Camera shutter device with two-arm lever

Abstract

The present invention relates to a camera shutter device including an optical aperture (1) and an electromagnetic drive (2) having a linearly guided moving part fixedly disposed in the optical aperture (1), the moving part being fixedly connected to a first shutter blade (3) to form a unit (23). The unit (23) is connected to a drive end (4.1) of a two-arm lever (4) that is rotatable about a rotation axis (4.0). A counterweight (5) is provided at an output end (4.2) of the two-arm lever (4). A second gravitational force (F2) acting on the counterweight (5) generates a second torque (M2) about the rotation axis (4.0) of the two-arm lever (4) that counteracts a first torque (M1) generated by a first gravitational force (F1) acting on the unit (23).

Description

[Technical Field]

[0001] The present invention relates to a shutter device for a camera module (e.g. an infrared camera module) for use in particular in various kinds of photographic and thermal imaging devices and devices for measuring the image quality of lenses and calibrating image sensors, which shutter device uses electromagnetic forces for opening and closing, as is generally known from the patent literature. [Background technology]

[0002] Shutter devices are used in cameras and optical sensors to interrupt the light beam path when necessary. The main challenge in the design of such shutter devices is the ongoing miniaturization of camera modules under increasing demands on heat generation, operating time, lifetime, operating temperature, cost, etc. Known solutions include iris diaphragms, focal plane shutters or pivotable or guided shutters driven by electromagnetic forces or by motors.

[0003] In infrared or thermal imaging applications, to correct for certain detector parameters that frequently vary over time during camera operation, it is necessary to perform so-called "dark frame calibrations" at certain time intervals, where the shutter device is closed and the resulting dark image is used for offset correction. In radiometric cameras, such shutter devices also serve as temperature references to improve measurement accuracy.

[0004] Patent Document 2 discloses a shutter mechanism operated by electromagnetic force, in which there is a time interval between the opening and closing pulses. The shutter element is braked in a certain position by a stopper. At that time, it vibrates after the collision due to the kinetic energy still present. These vibrations may cause errors in the exposure time or blur the image because they are transmitted to the sensor.

[0005] Patent Document 3 discloses a shutter device for a camera module, comprising a frame, two shutter blades (shutter foils), a permanent magnet, a spring, two linear sliding structures, an electromagnet, and a light-transmitting zone. Each of the two shutter blades has two sliding cylinders, through which they are guided between two positions on two linear sliding structures arranged parallel to each other, designated as guide cylinders. The sliding cylinders on the shutter blades are permanent magnets. An electromagnet is centrally disposed on each of the guide cylinders. Depending on its polarity, it attracts or repels the sliding cylinders, designated as permanent magnets, against the spring force of a compression spring disposed around the guide cylinders. In the power-off state, the shutter blades abut against the frame, which acts as a stopper, in the first position, where the shutter blades release the light-transmitting zone. In the second position, the shutter blades close, slightly overlapping the light-transmitting zone. The sliding cylinders contact the electromagnets due to the effect of electromagnetic force. The same problem exists here, namely, vibration occurs at the end of the shutter element's movement.

[0006] A disadvantage of many prior art camera shutter devices that use electromagnetic forces to move a shutter blade between two positions is that a permanent magnet or ferromagnetic mass is actuated by a force resulting from a magnetic field to accelerate its mass and move the associated shutter blade between two positions without frequently damaging it directly or indirectly, and the shutter blade may rebound from its final position and unintentionally partially reopen or close the light beam path for a short period of time.

[0007] A shutter mechanism actuated by electromagnetic force is known from US Pat. No. 5,629,499, in which a shutter element opens an exposure aperture with an opening pulse and closes it with a closing pulse, whereby shock vibrations of the shutter element in the reverse position are avoided by the opening pulse partially overlapping the closing pulse, so that the shutter element releases most of its kinetic energy before reaching the reverse position.

[0008] The aforementioned patent document 5 discloses a camera shutter device having two shutter blades, each of which is connected to a linearly guided moving part of an electromagnetic drive via a rotatably mounted connecting member. The shutter blades and their respective moving parts are moved symmetrically in opposite directions relative to the axis of the rotatably mounted connecting member. Due to the substantially horizontal axis, the weight force of each moving part on the axis of the connecting member thus generates a torque that counteracts the torque generated by the weight force of the shutter blade. Therefore, the torques compensate each other, so that the release movement of each shutter blade between the open and closed positions can be performed with relatively little force. Any shock to the shutter blades that occurs when the release movement is stopped in two positions is kept to a minimum.

[0009] A double rocker is provided as a guide for the shutter blade in all exemplary embodiments of the aforementioned Patent Document 5. One arm of the rocker has a pin that engages with a first slot formed in the output end of the rotatably mounted connecting member. A second slot is formed in the other input end of the rotatably mounted connecting member, into which a pin provided in the moving part of the electromagnetic drive unit engages. The moving part of the electromagnetic drive unit, guided by a cylindrical coil, and the shutter blade are guided linearly and parallel to each other.

[0010] Patent Document 6 discloses an electromagnetically operated shutter having two shutter blades. The shutter blades are arranged symmetrically on one side of the exposure opening and are arranged to move in opposite directions along a common linear axis, the opposite blades being connected via a connecting element. 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, and the movement of the shutter blades can be slowed down. However, when the power is turned off, the shutter position is undefined.

[0011] Patent Document 7 discloses an electromagnetically operated camera shutter with two shutter blades. Each shutter blade is tilted about a pivot point and connected at a common bearing to a spring-loaded return lever, which is connected to an electromagnetic linear drive. The electromagnetic linear drive opens the shutter against the spring force of the return lever. The return lever has a counterweight to compensate for the weight force of the shutter mechanism acting on the return lever. This allows the shutter to be operated independently of the camera position.

[0012] The aforementioned patent document 1 discloses a camera shutter device having an optical aperture and an electromagnetic drive fixedly arranged relative thereto. A shutter blade is mounted on a linear guide section, and the shutter blade is movable between an open position exposing the optical aperture and a closed position covering the optical aperture. A two-arm lever is provided, pivotable about a pivot point and connected at its input end to the linear guide section, with a counterweight at its output end. The counterweight generates a torque on the pivot shaft, which counteracts the torque generated by gravity. A particular disadvantage of the above-mentioned shutter device is that a separate electric motor drive is required to move each of the two shutter blades. The shutter device is also unstable when powered off; vibrations, particularly shocks or variations in the actuation direction, can cause the shutter blades to move from their respective positions. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] DE2707175A1 [Patent Document 2] DE1447470A [Patent Document 3] CN202748581U [Patent Document 4] DE2642601C2 [Patent Document 5] DE3017893A1 [Patent Document 6] US4171987A [Patent Document 7] GB2235541A Summary of the Invention [Problem to be solved by the invention]

[0014] It is an object of the present invention to provide a camera shutter device that can have a more compact design. [Means for solving the problem]

[0015] This object is achieved by a camera shutter device according to the present invention, which includes an optical aperture, an electromagnetic drive unit fixedly installed relative to the aperture, a first shutter blade, and a two-arm lever. The electromagnetic drive unit has a linearly guided moving portion. The first shutter blade is movable between an open position exposing the optical aperture and a closed position covering the optical aperture. The two-arm lever is divided into an input end and an output end by a pivot position, and can pivot around the pivot position over a pivot angle range. The pivot position is located on a rotation axis fixed relative to the optical aperture, and the input end is in communication with the moving portion. The first shutter blade forms a unit fixedly connected to the moving part and has a counterweight at the output end of the two-arm lever, and a second gravitational force acts on the counterweight, producing a second torque about the axis of rotation that counteracts the first torque produced by the first gravitational force acting on the unit. Due to the first shutter blade being fixedly connected to the moving part and forming a unit therewith, and the presence of a counterweight at the output end of the two-arm lever, a second gravitational force acts on the counterweight which generates a second torque about the axis of rotation which counteracts the first torque caused by the first gravitational force acting on the unit.

[0016] The essence of the invention resides in the fact that the camera shutter device comprises either a first permanent magnet having at least one magnetic surface, which is assigned to the counterweight and fixedly arranged within the rotation angle range, thereby holding the counterweight in the open and closed positions by the magnetic force of the first permanent magnet, or first and second permanent magnets, each having at least one magnetic surface, which are assigned to the counterweight and arranged, thereby holding the counterweight in the open and closed positions by the magnetic force of the first or second permanent magnet.

[0017] In particular, the counterweight is made of a ferromagnetic material and is arranged such that one of the at least one magnetic surface faces one of two different surface portions of the outer periphery of the counterweight in each of the open and closed positions.

[0018] Advantageously, the counterweight is made of a ferromagnetic material and has at least two magnetic surfaces, one of which faces a surface portion of the inner circumferential surface of the counterweight in the open position and the other of which faces a different surface portion of the inner circumferential surface of the counterweight in the closed position.

[0019] Alternatively, the first permanent magnet is attached to a counterweight, and a magnetic armature having two end faces facing the counterweight is arranged within the rotation angle range, with one of the at least one magnetic face being 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.

[0020] In particular, the counterweight is made of a ferromagnetic material, and the first and second permanent magnets are arranged facing each other outside the rotation angle range, with one of the at least one magnetic surface of the first permanent magnet facing a surface portion of the outer circumferential surface of the counterweight in the open position, and one of the at least one magnetic surface of the second permanent magnet facing another surface portion of the outer circumferential surface of the counterweight in the closed position.

[0021] Advantageously, in each of the open and closed positions, the respective magnetic surfaces and the respective surface portions surround a gap which is narrower than any distance between the counterweight and the first and second permanent magnets during movement between the open and closed positions.

[0022] The counterweight advantageously comprises a second shutter blade fixedly connected to a linearly guided connecting rod which together with the second shutter blade forms a counterweight and which is rotatably mounted on the output end of the two-arm lever.

[0023] Advantageously, the electromagnetic drive is a solenoid having a coil and a ferromagnetic or permanent magnetic armature core attached to a plunger, the plunger being the moving part.

[0024] The ratio of the stroke length of the electromagnetic drive to the overall length of the camera shutter device in the direction of said stroke length is advantageously greater than 1:2.

[0025] For this purpose, the coil has a bobbin and advantageously at least two-phase windings, so that the movement of the plunger is caused simultaneously by both attractive and repulsive forces acting locally one after the other in the direction of the stroke length.

[0026] Particularly advantageously, the bobbin is a linear sliding guide for the plunger.

[0027] It is also advantageous if a ferromagnetic enclosure is provided surrounding the coil, thereby increasing the magnetic flux generated inside the coil and reducing the stray magnetic field generated around the coil.

[0028] The camera shutter device described in the aforementioned Patent Document 5 is clearly based on the consideration of at least partially compensating for the gravitational forces acting on the mass of the moving part of the electromagnetic drive unit, which also have gravitational forces acting on the shutter blade. For this purpose, the moving part and the shutter blade are connected to each other via a connecting member that is arranged to rotate around a pivot point. The pivot point is located between two pins, one on the shutter blade and one on the moving part, that are guided in elongated holes formed in the connecting member.

[0029] The invention is based on the discovery that a camera shutter device becomes more compact and more stable if the shutter blades are directly and fixedly connected to the moving part of the electromagnetic drive. A counterbalancing torque is generated by a counterweight which may also include a second shutter blade, so that one and two shutter blades can be driven by a single electromechanical drive.

[0030] The invention will be explained in more detail below with reference to exemplary embodiments and drawings. [Brief explanation of the drawings]

[0031] [Figure 1] 1 illustrates a first exemplary embodiment of a camera shutter device having a shutter blade (shutter foil) and a counterweight that is rotatable between a first permanent magnet and a second permanent magnet. [Figure 2] FIG. 10 shows a second exemplary embodiment, in which the counterweight is rotatable relative to the first permanent magnet. [Figure 3] FIG. 10 shows a third exemplary embodiment, in which the counterweight is rotatable relative to the first permanent magnet. [Figure 4] FIG. 10 illustrates a fourth exemplary embodiment in which a first permanent magnet is fixedly connected to a counterweight and is rotatable relative to a ferromagnetic armature. [Figure 5] FIG. 10 shows a fifth exemplary embodiment having two shutter blades. [Figure 6] FIG. 10 is a detailed exploded view of the solenoid and the first shutter blade. DETAILED DESCRIPTION OF THE INVENTION

[0032] In all embodiments, the camera shutter device according to the invention comprises an optical aperture 1, an electromagnetic drive 2 fixedly arranged relative to it and having a linearly guided moving part, and a first shutter blade 3 forming a unit 23 fixedly connected to the moving part.

[0033] The shutter blade 3 is movable to an open position (see Figures 1a and 2a) exposing the optical aperture 1, and to a closed position (see Figures 1b and 2b) covering the optical aperture 1. In addition, a two-arm lever 4 is provided, which is divided into an input end 4.1 and an output end 4.2 by a pivot point P and is rotatable about the pivot point P over a pivot angle range α. The pivot point P is located on a rotation axis 4.0 fixed with respect to the optical aperture 1. The input end 4.1 of the two-arm lever 4 communicates with the moving part by a rotary joint formed by a pin engaging in an elongated hole, and a counterweight 5 is provided at the output end 4.2 of the two-arm lever 4.

[0034] A first gravitational force F1, essentially determined by the mass of the plunger 8.2 and the first shutter blade 3, acts on the unit 23, while a second gravitational force F2, determined by its mass, acts on the counterweight 5.

[0035] A first gravitational force F1 generates a first torque M1 about the axis of rotation 4.0, which counteracts a second torque M2 about the axis of rotation 4.0 generated by a second gravitational force F2. The first and second torques M1, M2 are not necessarily constant and equal in the closed and open positions and throughout the intermediate movement sequences, but they always act in opposite rotational directions and largely compensate each other.

[0036] The optical aperture 1 may be a physically unrestricted area through which radiation impinges on the detector. It may also be an opening in a diaphragm or the receiving surface of a detector. The optical aperture 1 may have any shape, for example a round shape or preferably a rectangular shape, as shown in the following exemplary embodiment. Only the shape of the first shutter blade 3, or also the shape of the second shutter blade 7, as shown in the second exemplary embodiment, must match this.

[0037] Therefore, an embodiment of a camera shutter device having only a one-component shutter, which has only the first shutter blade 3, is advantageous for the use of the camera shutter device for offset adjustment in (especially thermal) infrared cameras (NUC, non-uniformity correction), where it is important that the shutter, which simply closes the optical aperture 1 during at least one image acquisition cycle, has a temperature that is as precisely uniform as possible over its surface. Thus, in the case of a two-component shutter with a first and second shutter blade 3, 7, which inevitably have different relative positions with respect to existing heat sources or heat sinks in the device, the temperature difference that occurs between the first and second shutter blade 3, 7 may already result in the shutter being less suitable for offset adjustment.

[0038] Nevertheless, the embodiment with first and second shutter blades 3, 7 may also be advantageous for other applications.

[0039] For both the camera shutter device having only the first shutter blade 3 as part of the counterweight 5 and the camera shutter device embodiment having the first shutter blade 3 and the second shutter blade 7, it is advantageous if a first permanent magnet 6.1 or first and second permanent magnets 6.1, 6.2 are arranged in association with the counterweight 5 to magnetically hold the counterweight 5 in the open and closed positions when the electromagnetic drive 2 is in the powered off state.

[0040] Each of the first and second permanent magnets 6.1, 6.2 has at least one magnetic surface 14. For the purposes of this description, a magnetic surface 14 is understood to be a surface having at least one magnetic pole.

[0041] In the following five exemplary embodiments, four of which each have only the first shutter blade 3 and one of which also have the second shutter blade 7, will be described with reference to the drawings.

[0042] According to a first exemplary embodiment, shown in the open position in FIG. 1 a and in the closed position in FIG. 1 b, the camera shutter device comprises only a first shutter blade 3 .

[0043] The counterweight 5 is made of a ferromagnetic material and is provided with first and second permanent magnets 6.1, 6.2 to 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 preferably two identical bar magnets with the same holding force and axis of symmetry, aligned with each other. The counterweight 5 has the shape of a round disk, the center of which is aligned with the center in the closed and open positions. The magnetic surface 14 facing the counterweight 5, which includes, for example, the north or south pole of the first or second permanent magnet 6.1, 6.2, respectively, is a generally flat surface or preferably a cylindrical section surface with a radius slightly larger than that of the counterweight 5.

[0044] Advantageously, the first and second permanent magnets 6.1, 6.2 do not act as stops themselves, and a gap 12 remains between the counterweight 5 and the first and second permanent magnets 6.1, 6.2, respectively, in the open and closed positions. The gap 12 is advantageous for limiting the holding force, in particular to prevent wear of the magnetic surface 14. The gap 12 is narrower than any distance between the counterweight 5 and the first and second permanent magnets 6.1, 6.2, respectively, during movement between the open and closed positions. This statement also advantageously applies to further exemplary embodiments described below.

[0045] The pivot angle range α is advantageously limited by the stroke length or by a mechanical stop against which the moving part or the two-arm lever 4 abuts. The electromagnetic drive 2 is realized here by a solenoid 8 having a coil 8.1 and a ferromagnetic or permanently magnetized armature core 8.2.1 attached to a plunger 8.2, which here represents the moving part of the electromagnetic drive 2.

[0046] As shown in Figure 6, the coil 8.1 has a bobbin 8.1.1 which not only serves as a support for the windings 8.1.2 but also advantageously as a sliding guide 10 for the plunger 8.2. For this purpose, the bobbin 8.1.1 extends beyond the length intended to accommodate the windings 8.1.2 and is formed with an elongated hole along its extension. The plunger 8.2, which is fixedly connected to the first shutter blade 3, can therefore slide inside the bobbin 8.1.1. No additional components are required to guide the plunger 8.2.

[0047] The first shutter blade 3, fixedly connected to the plunger 8.2, is linearly guided between the open and closed positions in a direction determined by the movement direction of the armature core 8.2.1, while the two-arm lever 4 is pivoted about a fixed pivot point P through 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 total length of the camera shutter device. The total length is the maximum extension of the camera shutter device in the direction of movement of the armature core 8.2.1. The connection between the two-arm lever 4 and the unit 23 is made via a pin-slot connection. Thus, during the operating sequence, the distance between the application point of the first weight force F1 and the pivot point P changes, thus changing the length of the first lever arm r1, which changes the first torque M1. The length of the second lever arm r2 remains constant. Furthermore, both torques M1 and M2 change due to changes in the angles φ1 and φ2. The first and second torques M1 and M2 do not necessarily change equally.

[0048] Due to the direct connection of the moving part, which in this first exemplary embodiment is the plunger 8.2, with the first shutter blade 3, the movement of the armature core 8.2.1 is transmitted with a 1:1 transmission ratio. To accommodate the winding 8.1.2, a short length on the bobbin 8.1.1 can be dimensioned compared to the range of movement of the plunger 8.2. The winding 8.1.2 is designed as at least a two-phase winding. It may consist of at least two bipolar single windings arranged one after the other on the bobbin 8.1.1, or a single-polarity winding set with two halves wound in opposite directions. The time-shifted, and therefore phase-shifted, control results in a relatively longer stroke length than that achievable with a coil having only a single winding of the same winding length. Longer stroke lengths can also be achieved by using a permanent magnet armature core 8.2.1 and alternating the use of attractive and repulsive forces by reversing the direction of the magnetic field in the coil 8.1. In the case of a single winding of both poles, the current is reversed for this purpose; in the case of a set of windings of one pole, the current is applied alternately to one or the other half of the winding.

[0049] Advantageously, the coil 8.1 is partially or completely surrounded by a ferromagnetic enclosure 11. The enclosure 11 increases the magnetic flux generated inside the coil 8.1 and reduces the stray magnetic field generated around the coil 8.1.

[0050] The second exemplary embodiment, shown in Fig. 2a in the open position and in Fig. 2b in the closed position, differs from the first exemplary embodiment and the previously described modified embodiment in that only the first permanent magnet 6.1 is present, its arrangement relative to the counterweight 5, and the geometric shape of the counterweight 5. Here, the shape of the counterweight 5 represents a segment of a round disk having two flat surface sections on its outer periphery that form an angle of less than 180° with respect to each other. One of the flat surface sections is opposite and parallel to the same magnetic surface 14 of the first permanent magnet 6.1 in the open or closed position, respectively. For this purpose, the first permanent magnet 6.1 is arranged within a rotation angle range α, where the magnetic surface 14 is a flat surface.

[0051] The third exemplary embodiment, shown in Fig. 3a in the open position and in Fig. 3b in the closed position, differs from the second exemplary embodiment in the shape of the counterweight 5. Here, the counterweight 5 has the shape of a wrench and has an inner circumferential surface that presents two flat surface areas, each facing a flat magnetic surface 14 in the open or closed position, with identical gaps 12 of equal thickness and width. A first permanent magnet 6.1 is arranged within the pivot angle range α and within the counterweight 5.

[0052] According to a fourth exemplary embodiment shown in Fig. 4a in the open position and in Fig. 4b in the closed position, the first permanent magnet 6.1 is fixedly attached to the counterweight 5 within the pivot angle range α and radially aligned with the pivot position P, so that the counterweight 5 itself does not need to be made of a ferromagnetic material in this case. A ferromagnetic armature 13 having two flat end faces 13.1 facing the pivot position P is also fixedly fixed within the pivot angle range α. In the open and closed positions, one of the end faces 13.1 faces each of the same magnetic surfaces 14, forming equal gaps 12.

[0053] The surface sections of the magnetic surface 14, the end face 13.1 or the inner or outer circumferential surface of the counterweight 5 are described in the exemplary embodiment as flat surfaces; they may also have 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 over the pivot angle range α can be clearly influenced by the design of the magnetic surface 14.

[0054] According to the fifth exemplary embodiment shown in Figures 5a and 5b, the counterweight 5 comprises a second shutter blade 7. This exemplary embodiment differs from the first exemplary embodiment only in the design of the counterweight 5.

[0055] The counterweight 5, which in the first exemplary embodiment is fixedly connected to the output end 4.2 of the two-arm lever 4 and thus moves along a circular path, moves linearly, as does the unit 23, perpendicular to the axis of rotation 4.0. For this purpose, unlike the unit 23, which is connected to the input end 4.1 of the two-arm lever 4 via a pin / slot connection, the counterweight 5 is rotatably connected to the output end 4.2 of the two-arm lever 4 via a pin / slot connection. Here, the length of the second lever arm r2 also changes during the movement sequence. Advantageously, compared to the connection of the first shutter blade 3 to the plunger 8.2, the second shutter blade 7 is attached to a connecting rod 9. The connecting rod 9 is made of a magnetic material and can therefore be held by the first or second permanent magnet 6.1, 6.2. Similar to the plunger 8.2, there is a pin on the connecting rod 9 that is guided in a slot formed in the two-arm lever 4.

[0056] A sliding guide 10 is provided for the linear guidance of the connecting rod 9. The first and second shutter blades 3, 7 are moved simultaneously in opposite directions by only one electromagnetic drive 2.

[0057] In particular, advantageous embodiments of the camera shutter device having only the first shutter blade 3 are significantly more compact than the prior art. Advantageously, the first or second permanent magnet 6.1, 6.2, which exerts a holding force in the direction of movement of the first shutter blade 3 in a position covering or exposing the optical aperture 1, ensures 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. [Explanation of symbols]

[0058] 1 optical aperture 2 Electromagnetic drive unit 3 First shutter blade 23 units 4 Two-arm lever 4.0 Rotation Axis 4.1 Input End 4.2 Output End 5 Counterweight 6.1 First permanent magnet 6.2 Second permanent magnet 7 Second shutter blade 8 solenoids 8.1 Coil 8.1.1 Bobbin 8.1.2 Windings 8.2 Plunger 8.2.1 Armature core 9 Connecting Rod 10 Slide Guide 11 Enclosure 12 Gap 13 Armature 13.1 Armature End Face 14 Magnetic Surface P rotation position α Rotation angle range M1 First Torque M2 Second Torque F1 1st weight force F2 2nd weight force φ1 1st angle φ2 2nd angle r1 First lever arm r2 second lever arm

Claims

1. A camera shutter device comprising: an optical aperture (1); an electromagnetic drive unit (2) fixedly disposed in the optical aperture (1) and having a linearly guided moving portion; a first shutter blade (3) movable between an open position exposing the optical aperture (1) and a closed position covering the optical aperture (1); and a two-arm lever (4) divided into an input end (4.1) and an output end (4.2) by a rotation position (P), and rotatable around the rotation position (P) over a rotation angle range (α), The pivot position (P) is located on a rotation axis (4.0) fixed relative to the optical aperture (1), the input end (4.1) is in communication with the moving part, the first shutter blade (3) forms a unit (23) fixedly connected to the moving part, there is a counterweight (5) at the output end (4.2) of the two-arm lever (4), and a second gravitational force (F ２ ) acts on the counterweight (5) and a first gravitational force (F １ ) generated by the first torque (M １ A second torque (M) about the rotation axis (4.0) that cancels out the ２ ) in a camera shutter device, a first permanent magnet (6.1) having at least one magnetic surface (14) is fixedly arranged within the rotation angle range (α) and assigned to the counterweight (5), so that the counterweight (5) is held in the open and closed positions by the magnetic force of the first permanent magnet (6.1); or a camera shutter device, characterized in that first and second permanent magnets (6.1, 6.2), each having at least one magnetic surface (14), are provided and are assigned to and arranged on the counterweight (5), so 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. 2. The camera shutter device according to claim 1, characterized in that, when only the first permanent magnet (6.1) is present, the counterweight (5) is made of a ferromagnetic material and one of the at least one magnetic surface (14) is arranged to face one of two different surface portions of the outer circumferential surface of the counterweight (5) in each of the open and closed positions.

3. 2. The camera shutter device according to claim 1, wherein, when only the first permanent magnet (6.1) is present, the counterweight (5) is made of a ferromagnetic material and has at least two magnetic surfaces (14), one of which is arranged to face a surface portion of the inner circumferential surface of the counterweight (5) in the open position, and the other of which is arranged to face a different surface portion of the inner circumferential surface of the counterweight (5) in the closed position.

4. When only the first permanent magnet (6.1) is present, the first permanent magnet (6.1) is attached to the counterweight (5), and a magnetic armature (13) having two end faces (13.1) facing the counterweight (5) is arranged within the rotation angle range (α); 2. The camera shutter device according to claim 1, wherein one of the at least one magnetic surfaces (14) is 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. 2. The camera shutter device according to claim 1, wherein, when the first and second permanent magnets (6.1, 6.2) are present, the counterweight (5) is made of a ferromagnetic material, the first and second permanent magnets (6.1, 6.2) are arranged opposite each other outside the rotation angle range (α), one of the at least one magnetic surface (14) of the first permanent magnet (6.1) is arranged facing a surface portion of the outer circumferential surface of the counterweight (5) in the open position, and one of the at least one magnetic surface (14) of the second permanent magnet (6.2) is arranged facing another surface portion of the outer circumferential surface of the counterweight (5) in the closed position.

6. 6. A camera shutter device according to claim 2, 3, 4 or 5, characterized in that the respective magnetic surfaces (14) and the respective surface portions or end faces (13.1) of the outer circumferential surface of the counterweight (5) surround a gap (12) in the open position and the closed position, the gap (12) being narrower than any distance between the counterweight (5) and the first and second permanent magnets (6.1, 6.2) during movement between the open position and the closed position.

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

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

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

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

2.

11. 10. Camera shutter device according to claim 9, characterized in that the coil (8.1) comprises a bobbin (8.1.1) and at least two phase windings (8.1.2).

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

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

Images