CAMERA SHUTTER DEVICE WITH A DOUBLE-SIDED LEVER

Description

[0001] The invention relates to a shutter device for a camera module (e.g. an IR camera module), in particular for use in various types of photographic and thermal imaging devices, as well as devices for measuring the image quality of lenses and for calibrating image sensors, which uses electromagnetic forces for opening and closing, as is generically known from DE 27 07 175 A1.

[0002] Shutter devices are used in cameras and optical sensors to interrupt the optical beam path when necessary. A major challenge in the design of such shutter devices is the ongoing miniaturization of camera modules, coupled with increasing demands on heat generation, response time, lifetime, operating temperature, cost, and so on. Common solutions include iris diaphragms, focal plane shutters, or pivoting or guided shutter blades driven electromagnetically or by a motor.

[0003] In infrared or thermal imaging applications, it is necessary to perform a so-called "dark frame calibration" at certain intervals to correct certain detector parameters that often drift during camera operation. This involves closing a shutter, and the resulting dark image is used for offset correction. In radiometric cameras, such a shutter also serves as a temperature reference to improve measurement accuracy.

[0004] DE 1 447 470 A discloses an electromagnetically actuated shutter mechanism in which there is a specific time interval between an opening and closing pulse. The shutter element is decelerated by stops in a specific position. After impact, it vibrates due to the remaining kinetic energy. These vibrations can lead to inaccurate exposure times or image blur due to the transmission of vibrations to the sensor.

[0005] From CN 202 748 581 U, a shutter device for a camera module is known, comprising a frame, two shutter blades, permanent magnets, springs, two linear sliding structures, electromagnets, and a light transmission zone. The two shutter blades each have two sliding cylinders, via which they are guided between two positions on the two parallel linear sliding structures, which are designed here as guide cylinders. The sliding cylinders on the shutter blades are permanent magnets. An electromagnet is arranged centrally on each guide cylinder, which, depending on the polarity, attracts or repels the sliding cylinders, which are designed as permanent magnets, against the spring forces of the compression springs arranged around the guide cylinders. When de-energized, the shutter blades are in a first position, in which the shutter blades expose the light transmission zone, and the frame acts as a stop.In the second position, the shutter blades close the light transmission zone, slightly overlapping each other. The sliding cylinders rest against the electromagnet under the influence of magnetic force. The same problems exist here, namely the occurrence of vibrations at the end of the shutter element's travel.

[0006] A disadvantage of many prior-art camera shutter devices that use magnetic force to move a shutter blade into two positions is that the magnetic field exerts a force on a permanent magnet or a ferromagnetic body, accelerating its mass and moving the associated shutter blade directly or indirectly, often undamped, into the two positions. The shutter blade can rebound from the end positions and inadvertently partially open or close the optical beam path again for a short time.

[0007] DE 26 42 601 C2 discloses an electromagnetically actuated shutter mechanism in which a shutter element opens an exposure aperture with an opening pulse and closes it with a closing pulse. Impact oscillations at the reversal points of the shutter element are avoided by partially overlapping the opening pulse with the closing pulse, causing the shutter element to release most of its kinetic energy before reaching a reversal point.

[0008] From the aforementioned DE 30 17 893 A1, a camera shutter device with two shutter blades is known, each of which is connected via a rotatably mounted connecting link to a linearly guided movable part of an electromagnetic drive. The shutter blades and their respective associated movable parts are moved in opposite directions to one another symmetrically to an axis of the rotatably mounted connecting links. Thus, with a substantially horizontal alignment of the axis, the weight of the movable parts on the axis of the connecting links creates a torque that counteracts a torque caused by the weight of the shutter blade. The running movement of the respective shutter blade between an open position and a closed position can thus be carried out with considerably less force, since the torques compensate for each other.Any impact of the shutter blade when stopping the running movement in either position is kept to a minimum.

[0009] In all embodiments of the aforementioned DE 30 17 893 A1, a double rocker arm is provided as a guide for the closure blades. One arm of the rocker arm is provided with a pin that engages a first elongated hole formed at an output-side end of the rotatably mounted connecting link. At the other, drive-side end of the rotatably mounted connecting link, a second elongated hole is formed, into which a pin located on the movable part of the magnetic drive engages. The movable part of the magnetic drive, guided in a cylindrical coil, and the closure blade are guided linearly parallel to each other.

[0010] An electromagnetically operated shutter known from US Pat. No. 4,171,987 A has two shutter blades. The shutter blades are arranged symmetrically on both sides of an exposure aperture and are mounted for movement in opposite directions along a common linear axis, with the opposing movement being coupled via a connecting link. The free ends of the shutter blades are each designed as an electromagnetic linear drive. One drive is used to open the shutter and one to close it, so that the movement of the shutter blades can also be decelerated. However, when de-energized, the position of the shutter is undefined.

[0011] GB 2 235 541 A discloses an electromagnetically operated camera shutter with two shutter blades. The shutter blades are each pivotally mounted around a pivot point and connected at a common bearing point to a spring-loaded reset lever, which in turn is connected to an electromagnetic linear drive. The shutter is opened by the electromagnetic linear drive, counteracting the spring force of the reset lever. The reset lever has a counterweight that balances the weight of the shutter mechanism acting on the reset lever. This is intended to make the shutter independent of the camera's position when operating the shutter.

[0012] From the aforementioned DE 27 07 175 A1, a camera shutter device with an optical opening and an electromagnetic drive fixed to the latter is known. A shutter blade is attached to a linearly guided part and can be moved into an open position, exposing the optical opening, and a closed position, covering the optical opening. A two-sided lever pivotable about a pivot point is provided, which is connected to the linearly guided part at a drive-side end and has a counterweight at its output end. This counterweight exerts a torque on the rotational axis, which counteracts a torque caused by weight. A particular disadvantage of the aforementioned shutter devices is that a separate electric motor drive is required to move each of the two shutter blades.The locking device is also unstable when de-energized, meaning that vibrations, particularly impacts or vibrations acting in the direction of the actuating movement, can cause the locking leaves to move from their respective positions.

[0013] It is the object of the invention to provide a camera shutter device which can be made more compact.

[0014] This object is achieved for a camera shutter device according to the invention with an optical opening and an electromagnetic drive fixed to the optical opening, a first shutter blade and a two-sided lever.

[0015] The electromagnetic drive has a linearly guided, moving part.

[0016] The first shutter leaf is movable into an open position exposing the optical opening and into a closed position covering the optical opening.

[0017] The two-sided lever is divided by a pivot point into a drive end and an output end, and can be pivoted around the pivot point over a pivoting angle range. The pivot point is arranged on a rotation axis fixed to the optical opening, and the drive end is connected to the movable part.

[0018] The first locking blade forms a unit, firmly connected to the movable part, and a counterweight is located at the output end of the double-sided lever. A second weight force acts on the counterweight, causing a second torque about the rotation axis that counteracts a first torque caused by a first weight force acting on the unit.

[0019] Because the first locking blade is firmly connected to the movable part and forms a unit with it and there is a counterweight at the output end of the two-sided lever, a second weight force acts on the counterweight, which causes a second torque about the axis of rotation, which counteracts a first torque caused by a first weight force acting on the unit.

[0020] It is essential to the invention that either the camera shutter device has a first permanent magnet, which has at least one magnetic surface and is fixedly arranged within the pivot angle range in such a way that the counterweight is held in the open position and the closed position by the magnetic force of the first permanent magnet, or a first and a second permanent magnet, each having at least one magnetic surface, are present. These are assigned to the counterweight in such a way that the counterweight is held in the open position and the closed position by the magnetic force of the first or second permanent magnet.

[0021] In particular, the counterweight consists of a ferromagnetic material and one of the at least one magnetic surface is arranged in the open position and the closed position opposite one of two different surface sections of an outer peripheral surface of the counterweight.

[0022] It is advantageous if the counterweight consists of a ferromagnetic material and at least two magnetic surfaces are present, wherein one of the at least two magnetic surfaces is arranged opposite a surface section of an inner circumferential surface of the counterweight in the open position and another of the at least two magnetic surfaces is arranged opposite another surface section of the inner circumferential surface of the counterweight in the closed position.

[0023] Alternatively, it is advantageous if the first permanent magnet is attached to the counterweight and a ferromagnetic armature with two end faces facing the counterweight is arranged within the pivoting angle range, wherein one of the at least one magnetic surface 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.

[0024] In particular, the counterweight is made of a ferromagnetic material, and the first and second permanent magnets are arranged opposite each other outside the pivot angle range. One of the at least one magnetic surface of the first permanent magnet is arranged opposite a surface portion of an outer peripheral surface of the counterweight in the open position, and one of the at least one magnetic surface of the second permanent magnet is arranged opposite another surface portion of the outer peripheral surface of the counterweight in the closed position.

[0025] Advantageously, the respective magnetic surface and the respective surface section in the open position and the closed position each enclose a gap which is narrower than any distance of the counterweight from the first or second permanent magnet during the movement between the open and the closed position.

[0026] The counterweight may advantageously contain a second locking blade.

[0027] It is advantageous if the second locking blade is firmly connected to a linearly guided connecting rod, which together with the second locking blade forms the counterweight and is rotatably mounted on the output end of the two-sided lever.

[0028] Advantageously, the electromagnetic drive is a lifting magnet with a coil and a ferromagnetic or permanent magnetic armature core, wherein the armature core is attached to a plunger which represents the moving part.

[0029] The ratio of a stroke length of the electromagnetic drive to the length of the camera shutter device in the direction of the stroke length is advantageously greater than 1:2.

[0030] For this purpose, the coil has a coil body and advantageously at least a two-phase winding, whereby the movement of the plunger is caused simultaneously by both attractive forces and repulsive forces, which act locally one after the other in the direction of the stroke length.

[0031] It is particularly advantageous if the coil body represents a linear sliding guide for the plunger.

[0032] It is also advantageous to have a ferromagnetic enclosure surrounding the coil, which increases the magnetic flux generated inside the coil and reduces the stray field generated around the coil.

[0033] The camera shutter device described in the aforementioned DE 30 17 893 A1 is apparently based on the idea of ​​at least partially compensating the weight force acting on the mass of the movable part of an electromotive drive unit with the weight force acting on the shutter blade. For this purpose, the movable part and the shutter blade are connected to each other via a connecting link mounted for rotation about a pivot point. The pivot point is located between two pins, which are provided on the shutter blade and the movable part, respectively, and are each guided in an elongated hole formed in the connecting link.

[0034] The present invention is based on the finding that the camera shutter device can be designed more compactly and stably if the shutter blade is firmly connected directly to the movable part of the electromagnetic drive. A counteracting torque is generated by a counterweight, which may also contain a second shutter blade, allowing one or two shutter blades to be driven with a single electromechanical drive.

[0035] The invention is explained in more detail below using exemplary embodiments and drawings. These show: Fig. 1a and 1b: a first embodiment of a camera shutter device with a shutter blade, wherein the counterweight is pivotable between a first and a second permanent magnet, Fig. 2a and 2b: a second embodiment, wherein the counterweight is pivotable relative to a first permanent magnet, Fig. 3a and 3b: a third embodiment, wherein the counterweight is pivotable about a first permanent magnet, Fig. 4a and 4b: a fourth embodiment, wherein a first permanent magnet is fixedly connected to the counterweight and is pivotable relative to a ferromagnetic armature, Fig. 5a and 5b: a fifth embodiment with two shutter blades and Fig. 6: a detailed view with a lifting magnet and a first shutter blade in an exploded view.

[0036] A camera shutter device according to the invention contains in all embodiments an optical opening 1, an electromagnetic drive 2 fixedly arranged thereto with a linearly guided, movable part and a first shutter blade 3 which forms a unit 23 fixedly connected to the movable part.

[0037] The shutter blade 3 is in an open position releasing the optical opening 1 (see Fig. 1a and Fig. 2a ) and into a closed position covering the optical opening 1 (see Fig. 1b and Fig. 2b )movable. In addition, a two-sided lever 4 is present, which is divided by a pivot point P into a drive-side end 4.1 and an output-side end 4.2 and can pivot about the pivot point P over a pivot angle range α. The pivot point P is arranged on a rotation axis 4.0 that is fixed to the optical opening 1. The drive-side end 4.1 of the two-sided lever 4 is connected to the movable part via a rotary joint formed by a pin engaging in an elongated hole, and a counterweight 5 is present at the output-side end 4.2 of the two-sided lever 4.

[0038] A first weight force F 1 acts on the unit 23, essentially determined by the mass of the plunger 8.2 and the first closure leaf 3, while a second weight force F 2 acts on the counterweight 5, determined by its mass.

[0039] The first weight force F 1 causes a first torque M 1 about the rotation axis 4.0, which counteracts a second torque M 2 about the rotation axis 4.0, which is caused by the second weight force F 2. The first and second torques M 1 , M 2 are not necessarily constant and equal in the open and closed positions and throughout the movement in between, but always act in opposite directions of rotation and largely compensate each other.

[0040] The optical opening 1 can be a non-physically defined area through which radiation strikes a detector. It can also be the opening of an aperture or the receiving surface of a detector. It can have any shape, e.g., a round or, preferably, a rectangular shape, as shown in the following exemplary embodiments. Only the shape of the first shutter blade 3 or, as shown in a second exemplary embodiment, a second shutter blade 7, must be adapted accordingly.

[0041] A design of the camera shutter device with a single-part shutter, i.e., one that only has the first shutter blade 3, is advantageous for use of the camera shutter device for offset adjustment in a (particularly thermal) IR camera (NUC, Non-Uniformity Correction), where it is important that the shutter, which temporarily closes the optical opening 1 for at least one image acquisition cycle, has a temperature as uniform as possible on its surface. In the case of a two-part shutter, i.e., one that has the first and second shutter blades 3, 7, which necessarily have a different relative position to existing heat sources or heat sinks within the device, a resulting temperature difference between the first and second shutter blades 3, 7 can already make the shutter unsuitable for offset adjustment.

[0042] Nevertheless, a design with a first and a second closure leaf 3, 7 can also be advantageous for other applications.

[0043] Both for an embodiment of the camera shutter device with only the first shutter blade 3 and with the first shutter blade 3 and the second shutter blade 7 as part of the counterweight 5, it is advantageous if a first permanent magnet 6.1 or a first and a second permanent magnet 6.1, 6.2 are assigned to the counterweight 5 in order to hold the counterweight 5 in the open position and in the closed position when the electromagnetic drive 2 is de-energized by magnetic force.

[0044] The first and second permanent magnets 6.1, 6.2 each have at least one magnetic surface 14. A magnetic surface 14 in the context of this description is understood to be a surface that has at least one magnetic pole.

[0045] In the following five exemplary embodiments, four designs are described with reference to drawings, each of which has only the first closure leaf 3, as well as one design which also has a second closure leaf 7.

[0046] According to a first embodiment, shown in Fig. 1a in an open position and shown in Fig. 1b in a closed position, the camera shutter device has only the first shutter blade 3.

[0047] The counterweight 5 is made of a ferromagnetic material and includes a first and a second permanent magnet 6.1, 6.2 that hold the counterweight 5 in the open position and, alternatively, in the closed position when the electromagnetic drive 2 is de-energized. The first and second permanent magnets 6.1, 6.2 are advantageously two identical bar magnets with the same holding force and an axis of symmetry, which are arranged in alignment with one another on a straight line. The counterweight 5 has the shape of a round disk, the center of which lies on the straight line in the open and closed positions. The magnetic surfaces 14 facing the counterweight 5, here containing, for example, the north or south pole of the first or second permanent magnet 6.1, 6.2, are typically flat surfaces or, advantageously, cylindrical section surfaces with a slightly larger radius than that of the counterweight 5.

[0048] Advantageously, the first and second permanent magnets 6.1, 6.2 themselves do not act as stops, and a gap 12 remains between the counterweight 5 and the first or second permanent magnet 6.1, 6.2 in the open and closed positions. The gap 12 is advantageous for limiting the holding force and, in particular, prevents wear of the magnetic surface 14. The gap 12 is narrower than any distance between the counterweight 5 and the first or second permanent magnet 6.1, 6.2 during movement between the open and closed positions.

[0049] This statement also applies advantageously to the further embodiments described below.

[0050] The pivoting angle range α is advantageously limited by the stroke length or by mechanical stops against which, for example, the movable part or the two-sided lever 4 strikes. The electromagnetic drive 2 is implemented here by a lifting magnet 8, with a coil 8.1 and a ferromagnetic or permanent-magnetic armature core 8.2.1, which is attached to a plunger 8.2, which here represents the movable part of the electromagnetic drive 2.

[0051] The coil 8.1 has a coil body 8.1.1, which not only serves as a carrier for the winding 8.1.2, but also advantageously as a sliding guide 10 for the plunger 8.2, as shown in Fig. 6 For this purpose, it is extended beyond a length intended to accommodate the winding 8.1.2 and is slotted along the extension. The plunger 8.2, which is firmly connected to the first closure plate 3, can thus slide within the coil body 8.1.1. No additional component is required to guide the plunger 8.2.

[0052] The first shutter leaf 3, which is firmly connected to the plunger 8.2, is guided linearly between the open and closed positions in a direction predetermined by the direction of movement of the armature core 8.2.1, while the two-sided lever 4 is pivoted about a fixed pivot point P over a pivot angle range α. The movement of the armature core 8.2.1 occurs over a stroke length that is advantageously 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 direction of movement of the armature core 8.2.1. The connection to the two-sided lever 4 and the unit 23 is established via a pin-and-slot connection. Thus, during the movement sequence, the distance of the point of application of the first weight force F 1 from the pivot point P changes, and consequently the length of a first lever arm r 1 , which also changes the first torque M 1 . The length of a second lever arm r 2 remains constant.Furthermore, both torques M 1 , M 2 change due to the changes in the angles φ 1 , φ 2 . The first and second torques M 1 , M 2 do not have to change equally.

[0053] Through the direct connection of the movable part, which in this first embodiment is the plunger 8.2, with the first closure leaf 3, the movement of the armature core 8.2.1 is transmitted at a transmission ratio of 1:1. In order to be able to dimension a short length on the coil body 8.1.1 for accommodating the winding 8.1.2 compared to the range of movement of the plunger 8.2, the winding 8.1.2 is designed as an at least two-phase winding. It can consist of at least two bipolar individual windings arranged one behind the other on the coil body 8.1.1 or of unipolar winding pairs whose two halves are wound in opposite directions. A temporally and thus phase-shifted control leads to a comparatively longer stroke length than would be achievable with a coil with only one individual winding of the same winding length. A longer stroke length is also achieved when using a permanent-magnet armature core 8.2.1 and the alternating use of attractive and repulsive forces by reversing the direction of the magnetic field of coil 8.1. In bipolar single windings, the current flow is reversed; in unipolar winding pairs, current is alternately applied to one or the other half of the winding.

[0054] Advantageously, the coil 8.1 is partially or completely enclosed by a ferromagnetic housing 11, whereby a magnetic flux arising inside the coil 8.1 is increased and a stray field arising around the coil 8.1 is reduced.

[0055] The second embodiment, shown in Fig. 2a in an open position and shown in Fig. 2b in a closed position, differs from the first embodiment or versions of the mentioned modifications in that only a first permanent magnet 6.1 is present, by its arrangement relative to the counterweight 5 and the geometric shape of the counterweight 5. The shape of the counterweight 5 here represents a segment of a round disk, which has two flat surface sections on its outer circumferential surface that enclose an angle of less than 180° with each other, wherein one of the flat surface sections lies parallel to an identical magnetic surface 14 of the first permanent magnet 6.1 in the open or closed position. For this purpose, the first permanent magnet 6.1 is arranged within the pivoting angle range α. The magnetic surface 14 is a flat surface here.

[0056] The third embodiment, shown in Fig. 3a in an open position and in Fig. 3b In a closed position, it differs from the second embodiment in the shape of the counterweight 5. This counterweight 5 has the shape of an open-end wrench, with an inner circumferential surface featuring two flat surface areas. In the open or closed position, these face one of the flat magnetic surfaces 14, each with an identical gap 12 of the same thickness and width. The first permanent magnet 6.1 is arranged within the pivot angle range α and within the counterweight 5.

[0057] According to the fourth embodiment shown in Fig. 4a in an open position and in Fig. 4b In a closed position, the first permanent magnet 6.1 is fixedly attached to the counterweight 5 within the pivot angle range α and radially aligned to the pivot point P, which is why the counterweight 5 itself does not have to be made of a ferromagnetic material in this case. Within the pivot angle range α, a ferromagnetic armature 13 is also statically fixed, with two flat end faces 13.1 facing the pivot point P. In the open position and the closed position, one of the end faces 13.1 is opposite an identical one of the magnetic surfaces 14 and forms an identical gap 12.

[0058] The magnetic surfaces 14, the end faces 13.1, or the surface sections on an inner or outer circumferential surface of the counterweight 5 were described as flat surfaces in the exemplary embodiments; they can also take on other surface shapes, such as cylindrical, conical, or spherical surface sections. It is known to those skilled in the art that the specific course of the magnetic force during movement across the pivot angle range α can be specifically influenced by the design of the magnetic surfaces 14.

[0059] According to a fifth embodiment, shown in the Fig. 5a und Fig. 5b the counterweight 5 contains a second closure leaf 7. This embodiment differs from the first embodiment only in the design of the counterweight 5.

[0060] The counterweight 5, which in the first embodiment is firmly connected to the output-side end 4.2 of the double-sided lever 4 and is thus moved on a circular path, here moves like the unit 23 in a straight line and orthogonal to the axis of rotation 4.0. In this respect, it is comparable to the unit 23, which is connected to the drive-side end 4.1 of the double-sided lever 4 via a pin-slot connection, and is rotatably connected to the output-side end 4.2 of the double-sided lever 4 via a pin-slot connection, whereby the length of the second lever arm r 2 changes during the movement sequence. The second locking leaf 7 is advantageously attached to a connecting rod 9, comparable to the connection of the first locking leaf 3 to the tappet 8.2. The connecting rod 9 is made of a ferromagnetic material and can thus be held by the first or second permanent magnets 6.1, 6.2. As with the plunger 8.2, there is a pin on the connecting rod 9 which is guided in an elongated hole formed on the two-sided lever 4.

[0061] A sliding guide 10 is provided for linear guidance of the connecting rod 9. The first and second locking blades 3, 7 are moved simultaneously in opposite directions by a single electromagnetic drive 2.

[0062] In particular, an advantageous embodiment of the camera shutter device with only a first shutter blade 3 is significantly more compact compared to the prior art. By advantageously exerting a holding force in the direction of movement of the first shutter blade 3 by the first and second permanent magnets 6.1, 6.2 in the position covering the optical opening 1 or in the position uncovering the optical opening 1, it is ensured that the first shutter blade 3 is held in a stable position, even when shocks or vibrations act on the camera shutter device in the direction of movement. List of reference symbols

[0063] 1 optical aperture 2 electromagnetic drive 3 first shutter leaf 23 unit 4 two-sided lever 4.0 axis of rotation 4.1 drive end 4.2 output end 5 counterweight 6.1 first permanent magnet 6.2 second permanent magnet 7 second shutter leaf 8 lifting magnet 8.1 coil 8.1.1 coil body 8.1.2 winding 8.2 plunger 8.2.1 armature core 9 connecting rod 10 sliding guide 11 housing 12 gap 13 armature 13.1 end face of the armature 14 magnetic surface P pivot point α pivot angle range M 1 first torque M 2 second torque F 1 first weight F 2 second weight φ 1 first angle φ 2 second angle r 1 first lever arm r 2 second lever arm

Claims

1. A camera shutter device comprising an optical opening (1), an electromagnetic drive (2) fixedly arranged relative to the optical opening (1) and having a linearly guided movable part, a first shutter blade (3) movable to an open position exposing the optical opening (1) and to a closed position covering the optical opening (1), and a two-armed lever (4) divided by a pivot point (P) into an input end (4.1) and an output end (4.2) and pivotable about the pivot point (P) over a pivot angle range (α), wherein the pivot point (P) is arranged on an axis of rotation (4.0) fixedly arranged relative to the optical opening (1) and the input end (4.1) is connected to the movable part, the first shutter blade (3) forming a unit (23) fixedly connected to the movable part, and a counterweight (5) is present at the output end (4.2) of the two-armed lever (4), wherein a second weight force (F2) acting on the counterweight (5) causes a second torque (M2) about the axis of rotation (4.0) which counteracts a first torque (M1) caused by a first weight force (F1) acting on the unit (23), characterized in that a first permanent magnet (6.1), having at least one magnetic face (14), is fixedly arranged within the pivot angle range (α) in association with the counterweight (5) in such a way that the counterweight (5) is held in the open position and the closed position by the magnetic force of the first permanent magnet (6.1), or a first and a second permanent magnet (6.1, 6.2), each having at least one magnetic face (14), are provided, which are arranged in association with the counterweight (5) in such a way that the counterweight (5) is held in the open position by the magnetic force of the first permanent magnet (6.1) and 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, in case only the first permanent magnet (6.1) is present, said counterweight (5) is made of a ferromagnetic material and one of said at least one magnetic faces (14) is arranged opposite one of two different surface portions of an outer circumferential surface of said counterweight (5) in the open position and the closed position, respectively.

3. The camera shutter device according to claim 1, characterized in that, in case only the first permanent magnet (6.1) is present, said counterweight (5) is made of a ferromagnetic material and at least two magnetic faces (14) are present, one of said at least two magnetic faces (14) being arranged opposite a surface portion of an inner circumferential surface of said counterweight (5) in the open position and another of said at least two magnetic faces (14) being arranged opposite another surface portion of said inner circumferential surface of said counterweight (5) in the closed position.

4. The camera shutter device according to claim 1, characterized in that, in case only the first permanent magnet (6.1) is present, the first permanent magnet (6.1) is attached to the counterweight (5) and a ferromagnetic armature (13) with two end faces (13.1) facing the counterweight (5) is arranged within the pivot angle range (α), one of the at least one magnetic faces (14) being arranged opposite one of the two end faces (13.1) in the open position and opposite 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, in case the first and second permanent magnets (6.1,6.2) are present, said counterweight (5) is made of a ferromagnetic material and said first and second permanent magnets (6.1,6.2) are arranged opposite each other outside the pivot angle range (α) and one of the at least one magnetic faces (14) of said first permanent magnet (6.1) is arranged opposite a surface portion of an outer circumferential surface of the counterweight (5) in the open position, and one of the at least one magnetic faces (14) of the second permanent magnet (6.2) is arranged opposite another surface portion of the outer circumferential 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 respective magnetic face (14) and the respective surface portion of the outer circumferential surface of the counterweight (5) or the respective end face (13.1) in the open position and the closed position each enclose a gap (12) with each other which is narrower than any distance of the counterweight (5) from the first or second permanent magnet (6.1, 6.2) during the movement between the open and the closed position.

7. The camera shutter device according to any one of the preceding claims, characterized in that the counterweight (5) contains a second shutter blade (7).

8. The camera shutter device according to claim 5 and 7, characterized in that the second shutter blade (7) is fixedly connected to a linearly guided connecting rod (9) which, together with the second shutter blade (7), forms the counterweight (5) and is rotatably mounted on the output end (4.2) of the two-armed lever (4).

9. The camera shutter device according to claim 1, characterized in that the electromagnetic drive (2) is a solenoid (8), with a coil (8.1) and a ferromagnetic or permanent magnetic armature core (8.2.1), which is attached to a plunger (8.2), the plunger (8.2) being the moving part.

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

11. The camera shutter device according to claim 10, characterized in that the coil (8.1) comprises a bobbin (8.1.1) and an at least two-phase winding (8.1.2).

12. The camera shutter device according to claim 11, characterized in that the bobbin (8.1.1) is a linear sliding guide (10) for the plunger (8.2).

13. The camera shutter device according to claim 9, characterized in that a ferromagnetic enclosure (11) is provided which encloses the coil (8.1), whereby a magnetic flux arising inside the coil (8.1) is increased and a stray field arising around the coil (8.1) is reduced.