Optical arrangement and method for setting an optical component held by a mount into a periodic linear oscillation

Abstract

The invention relates to an arrangement for periodically moving an optical component.

Description

[0001] Optical arrangement and method for setting an optical component mounted with a mount into a periodic linear oscillation

[0002] Technical area

[0003] The invention relates to an arrangement for periodically moving an optical component.

[0004] State of the art

[0005] From JP2003315656 A a mobile phone with a camera is known in which the focus lens of the camera is vibrated by means of an eccentric in order to realize a vibration function for notifying the operator, whereby no additional vibration unit is required.

[0006] JPH07-162732 A discloses an autofocus system for a camera with a lens oscillating at 30 Hz, in which the direction of the focus position is determined by the oscillating lens. Disadvantages include the link between the oscillation frequency and the field frequency of the frame rate and the relatively high energy consumption of the oscillation excitation.

[0007] DE 2648419 A1 discloses a testing device for checking the position of the image plane of a lens. In this device, a lens is oscillated by means of an oscillating plate. The disadvantage is that the lens is moved along a curved path and, in addition, the lens can tilt relative to the optical axis. Therefore, this system can only achieve small oscillation amplitudes without compromising the optical quality of the image.

[0008] DE 10 2017 214 474 A1 discloses an actuator with an inherent position sensor for moving a lens to a focus position. The actuator's control bandwidth is chosen to be significantly larger than the mechanical resonance frequency of the spring-mass system in order to achieve a fast autofocus process. A disadvantage is the relatively high energy consumption of the drive.

[0009] US 2021 0 149 170 A1 discloses a method for recording a z-stack. The object of the invention

[0010] The object of the invention is to provide an optical arrangement and a method for setting an optical component mounted in a mount into periodic linear oscillation. The aim is to achieve low energy consumption and improved efficiency.

[0011] Solution to the task

[0012] The object is achieved by an optical arrangement according to claim 1 and a method according to claim 10. This method can be advantageously carried out with the optical arrangement.

[0013] Advantages of the invention

[0014] The advantage of the invention lies in the improved energy efficiency of the optical arrangement and the ability to quickly capture image sequences at different object planes. Due to the improved energy efficiency, the optical arrangement can be compact in design, resource-efficient in production, and sustainable in operation.

[0015] Description

[0016] In the following, an optical arrangement according to the invention and the method according to the invention are described.

[0017] The optical arrangement according to the invention comprises

[0018] • a carrier

[0019] • an optical component mounted with a mount, in particular wherein the optical component comprises at least one of the following elements: o a plane mirror, o a curved mirror, o an optical lens, o an optical lens group, o a light source o an image sensor at least one electrically operable linear drive element with an oscillating element and a stator, and • at least one return spring.

[0020] In the optical arrangement according to the invention

[0021] • the stator is mechanically connected to the carrier,

[0022] • the socket is mechanically connected to the oscillating element,

[0023] • the oscillating element is mounted so that it can move relative to the stator in one direction of movement,

[0024] • the linear drive element is designed to cause the mount with the optical component to oscillate linearly in the direction of movement,

[0025] • the return spring is intended to provide a restoring force between the oscillating element and the stator.

[0026] In addition, the optical arrangement has a resonance frequency f r The linear drive element is operable in such a way that the mechanical vibration has an oscillation frequency f that corresponds to the resonance frequency f r The optical component can therefore be moved periodically. Resonant operation can have the advantage that less drive energy is required than in non-resonant operation. This allows the drive element to be smaller. Furthermore, if the optical arrangement is implemented in a handheld device, a smaller accumulator can be used.

[0027] The optical component mounted in the mount can have an optical axis that runs, for example, in a z-direction. To mount the optical component, the mount can be ring-shaped. It is also possible for the optical component to be mounted on only one side of the mount. This means that the optical component is in mechanical contact with the mount only at one or more points, without the mount enclosing the component.

[0028] The carrier can be designed, for example, as an optical bench, a base plate or a housing.

[0029] The electrically operable linear drive element can drive a movement of the socket in a direction z. The direction z can be the direction of movement of the linear oscillation of the socket in the sense of a one-dimensional oscillation along a line. The linear drive element can comprise a ferromagnetic element and a magnetic coil, which exerts a force on the ferromagnetic element as a function of an electric current. The magnetic coil can be designed as a stator, i.e., be firmly connected to the carrier, and the ferromagnetic element can represent the oscillating element. Alternatively, the magnetic coil can represent the oscillating element and the ferromagnetic element the stator.

[0030] The return spring can also be referred to as a return spring arrangement. For example, the return spring can be designed as a spiral spring. This can be the cheapest solution. However, the return spring can fatigue due to mechanical stress. Advantageously, the return spring can be designed as a magnet arrangement comprising a first permanent magnetic element and a second permanent magnetic element. This can have the advantage that no mechanical stress is present. A repulsive magnetic coupling can exist between the first permanent magnetic element and the second permanent magnetic element. This can be achieved by having a similar pole, for example the north pole, of the second permanent magnetic element opposite a similar pole, for example also the north pole, of the first permanent magnetic element at a certain distance.This can generate a first repulsive force, for example in the z-direction, the strength of which can decrease with increasing distance. The return spring can also comprise a third permanent magnetic element. In this case, the other magnetic pole, for example the south pole, of the second permanent magnetic element can be opposed by a similar pole, for example also the south pole, of the third permanent magnetic element at a second distance, whereby a second repulsive force, for example in the -z-direction, is formed between the second and third permanent magnetic elements. For this purpose, the permanent magnetic elements can be magnetized in the z-direction. The -z-direction can mean the negative z-direction. The first and third permanent magnetic elements can be connected to the carrier, while the second permanent magnetic element can be connected to the socket.Since the first and second repulsive forces are oppositely directed and depend on the respective distance between the permanent magnetic elements, the first to third permanent magnetic elements form a return spring without mechanical contact. The second permanent magnetic element can be connected to the oscillating element or be identical to it. In the latter case, the second permanent magnetic element can therefore also function as an oscillating element. As a permanent magnet, it can also be a ferromagnetic element, which, in cooperation with the magnetic coil, can exert a force in one direction of movement. The first permanent magnetic element and the third permanent magnetic element can be designed as ring magnets. This allows the drive force of the linear drive element to be transferred to the socket on the coil axis.For this purpose, a fixed mechanical connection can be provided between the linear drive element and the socket.

[0031] The restoring force exerted by the return spring can be proportional to the elongation, which can also be described as a linear relationship. Elongation can be understood as the change in the position of the oscillating element relative to its force-free neutral position. Elongation can be equivalent to the elongation of the return spring, whereby compression of the spring can be considered a negative elongation. In a magnetic spring, elongation can be defined as the change in position of the movable magnetic element relative to its force-free neutral position.

[0032] In a particularly advantageous embodiment, the restoring force can depend non-linearly on the elongation. In particular, the restoring force can increase disproportionately as a function of the elongation. This can mean that the restoring force at the upper and lower ends of the deflection range is greater in magnitude than would be the case with a proportional dependence of the restoring force on the elongation. As a comparative proportional restoring force, one can choose one whose proportionality factor corresponds to the increase of the existing non-linear restoring force in the neutral position. Such a disproportionate dependence can be achieved, for example, with a return spring designed as a magnet arrangement. The disproportionality can be particularly pronounced if the static first and third permanent magnetic elements are arranged as close as possible to the ends of the intended deflection range, i.e.the amplitude of the second, movable, permanent-magnetic element. Advantageously, the minimum distance, measured in the direction of movement, between the second permanent-magnetic element and the first permanent-magnetic element at the end of the intended deflection range can be less than a third of this distance in the force-free neutral position, advantageously less than 25% and particularly advantageously less than 20%. The same minimum distance can be provided at the other end of the deflection range between the second and third permanent-magnetic elements. The non-linearity of the restoring force can be caused by the dipole character of the permanent-magnetic elements or can be particularly pronounced in its expression. Advantageously, the optical arrangement can have attenuation with a degree of attenuation D, wherein the quality factor Q=1 / (2*D) is between 5 and 10,000, in particular between 10 and 1,000, in particular between 20 and 100.Damping can be achieved, for example, through frictional forces in the linear guide. It is also possible to use a shock absorber to achieve a defined damping effect. It is also possible to provide an ohmic resistor parallel to the magnetic coil to achieve a defined damping effect on the oscillation of the optical arrangement.

[0033] The oscillation of the optical arrangement can cause a time-dependent force on the carrier. This can be unfavorable. To compensate for this force on the carrier, the optical arrangement can also include a compensation arrangement that can be set into counter-oscillation to generate an oppositely directed time-dependent force on the carrier. Ideally, this can make the carrier force-free.

[0034] The arrangement can advantageously comprise at least one sensor. In particular, the sensor can have a magnetic field sensor, a coil, a position sensor or a light barrier or be designed as such. The sensor can be provided to determine a position of the optical component and / or a speed of the optical component. For this purpose, the sensor can detect the position or speed of the oscillating element or the mount relative to the carrier. It is also possible for the sensor to detect the position or speed of the optical component. The sensor signal can be used to synchronize the periodic electrical energy for operating the linear drive element with the oscillation of the optical component. For this purpose, the sensor signal can be amplified and, if necessary, phase-shifted to control the electrical drive energy of the linear element.The sensor signal can also be used to determine the recording times for images. For this purpose, for example, an image can be triggered at specific positions on the optical component. It can be particularly advantageous if a first sensor is used to control the oscillation. A second sensor, in particular a position sensor, can then be used to trigger an action, such as an image capture, at specific positions on the optical component. It is also advantageous if only one sensor is used equally for both tasks.

[0035] Advantageously, the optical arrangement can also comprise a control unit and the arrangement can form a control loop with the control unit, with which the oscillation frequency f can be adjusted to the resonance frequency f ris controllable. For this purpose, the sensor signal can be fed to the control unit. For this purpose, a control system with electrical feedback can be designed

[0036] Advantageously, the optical arrangement can comprise at least one linear guide. This can be designed, for example, as a dovetail guide or as a roller bearing. The linear guide can be designed to be movable in the z-direction.

[0037] Advantageously, the vibration element can have an amplitude of 1 mm to 20 mm, in particular 2 mm to 10 mm, measured from the smallest to the largest deflection value (peak-to-peak value), and / or a resonance frequency f rbetween 5 Hz and 60 Hz, especially between 7.5 Hz and 30 Hz. If the restoring force depends disproportionately on the elongation, the resonance frequency can be varied within a certain resonance frequency range by changing the oscillation amplitude. This may make it possible to precisely tune the resonance frequency. In the case of strong nonlinearity at the ends of the deflection range, even a slight change in amplitude may be sufficient to provide a resonance frequency range accessible for frequency tuning, allowing the target value of the resonance frequency to be set despite all manufacturing tolerances of the components, such as the tolerances of the masses of the moving components and the remanence induction of the permanent magnetic elements. Furthermore, it may be possible for the mechanical resonance frequency to adjust itself if the linear drive element is driven at a predetermined target frequency.This may eliminate the need for electrical control of the frequency of the linear drive element. In other words, the mechanical resonance frequency of the mechanical oscillating system can be automatically adjusted to the specified target frequency of the drive element by controlling the amplitude, which would not be possible if the restoring force were proportional to the elongation.

[0038] To determine the disproportionate dependence of the restoring force on the elongation, one can proceed as follows. For each elongation s of the return spring, one can determine a restoring force F(s) and a first derivative F'(s)=dF(s) / ds. The first derivative in the neutral position can be denoted F'(0), and the first derivative at the points of smallest and largest elongation, i.e., the reversal points of the oscillation, can be denoted by F'(s m in) and F'(Smax). Then a ratio F'(s m in) / F'(0) and F'(sma x) / F'(0) form a measure of the disproportionality, whereby both ratios can be greater than 1.5, advantageously between 2 and 100, particularly advantageous between 3 and 30 and especially advantageous between 3 and 10. A high disproportionality can also, as explained below, favor an optimized oscillation form of the optical component. However, an excessively high disproportionality can lead to shaking of the arrangement as a result of increased recoil at the reversal points of the oscillation. Therefore, it can be useful to specify a maximum value of the disproportionality in addition to the minimum value. The distance between the reversal points of the oscillation can be referred to as the amplitude of the oscillation, whereby the elongation has a range {s m into the ma x} can be covered.

[0039] If, however, only a small amplitude were provided around the neutral position of the magnetic spring, the restoring force could be essentially proportional to the elongation. In this case, the advantages of disproportionality could not be utilized.

[0040] Advantageously, the linear drive element can comprise a coil. Advantageously, a capacitor can be connected in parallel with the coil, which can serve to tune an electrical resonance frequency to a mechanical resonance frequency of the optical arrangement.

[0041] Advantageously, the optical arrangement can be used to periodically adjust a focus position of the optical component.

[0042] Furthermore, a method for setting an optical component mounted with a mount into a periodic linear oscillation is specified, comprising the following steps:

[0043] • Providing a periodic electrical drive signal with multiple periods,

[0044] • Supplying the periodic electrical drive signal to an electrically operable linear drive element, wherein the linear drive element causes a driving force on the socket, wherein a position of the socket relative to a carrier changes periodically,

[0045] • Applying a restoring force dependent on the position of the socket by means of a return spring,

[0046] • Continuously recording a measured value of the position of the socket and / or the instantaneous speed of the socket by means of a first sensor,

[0047] • Feeding the measured value to a control unit,

[0048] Regulating the periodic electrical drive signal to a resonance frequency of the optical arrangement by means of the control unit and / or tuning the resonance frequency of the optical arrangement to a desired frequency by adjusting the amplitude of the oscillation of the optical component (2).

[0049] Advantageously, the oscillation of the optical component can be a sinusoidal oscillation. A sinusoidal oscillation can be easily generated using the linear drive element if an electrical drive signal of the same frequency, phase-shifted to the oscillation of the optical component, is provided, for example, by an electrical resonant circuit.

[0050] Alternatively, an optimized oscillation shape of the optical component may be advantageous, the temporal profile of which lies between a sine oscillation and a triangular oscillation of the same amplitude. For this purpose, a pure sine oscillation and a pure triangular oscillation can be used, which have the same frequency, phase, and amplitude as the oscillation of the optical component. In a range between a zero crossing and a maximum value of the oscillation of the optical component, the pure sine oscillation can represent an upper limit and the pure triangular oscillation a lower limit of the oscillation of the component. An approximately triangular oscillation shape can be promoted by a disproportionate dependence of the restoring force of the return spring on the elongation.With the optimized oscillation shape, the duration of the time intervals unusable for image acquisition around the direction reversal points of the movement of the optical element can be reduced.

[0051] Tuning the resonant frequency of the optical assembly to a desired frequency by adjusting the amplitude of the linear oscillation of the optical component can be achieved by making the restoring force of the return spring disproportionately dependent on the elongation. Increasing the amplitude can then increase the resonant frequency. Adjusting the amplitude of the linear oscillation of the optical component can be achieved by adjusting the electrical energy supplied to the linear drive element. Defined damping of the oscillation assembly within the optimal damping range specified above can improve the controllability of the resonant frequency.

[0052] Advantageously, the method according to claim can also comprise: • imaging an object onto an image sensor by means of the optical component, wherein, depending on the position of the mount, a plane on the object side is sharply imaged onto the image sensor,

[0053] • Continuously capture multiple images at different positions of the mount using the image sensor.

[0054] Advantageously, during continuous image capture, an image of the object can be triggered at a specific position of the mount. A second sensor can be provided for this purpose. This can be designed as a clock generator that triggers an image capture at each predetermined position of the mount. This sensor can, but does not have to, be identical to the first sensor. In this case, this sensor can be used both to record the measured value for the control unit for regulating the periodic drive signal and to trigger the image capture. However, it can also be advantageous to use two separate sensors. Although the latter can be more complex, it results in better accuracy of the image capture positions.

[0055] In order to be able to record the images continuously, the oscillation can be stationary, i.e. it can last with essentially the same frequency and amplitude for a certain period of time, for example for at least 1, 10 or 100 seconds. A sufficient number of images can then be recorded for precise analysis. It is also possible to rotate the object slowly relative to the optical arrangement during the stationary oscillation in order to record sequences of images from different viewing directions. This can make any undercuts in the surface of the object visible. It can also improve the accuracy of a three-dimensional model described below. Slow rotation can mean that the amount of twist is less than 5° per period of the oscillation, advantageously less than 2° and particularly advantageously less than 1°.The relative rotation can also be achieved by arranging the object in a fixed space and guiding the optical arrangement around the object at least in sections.

[0056] Advantageously, the method may also include:

[0057] Forming a z-stack from several of the acquired images of a period. Creating a two-dimensional image of increased depth of field from the z-stack and / or creating a three-dimensional model of the object from the z-stack.

[0058] Advantageously, the method may also include:

[0059] • Creating a two-dimensional or three-dimensional video from several successively produced two-dimensional images or three-dimensional models.

[0060] The figures show the following:

[0061] Fig. 1 shows a principle of an optical arrangement.

[0062] Fig. 2 shows a first embodiment.

[0063] Fig. 3 shows a principle of an optical arrangement with compensated bearing force.

[0064] Fig. 4 shows a second embodiment.

[0065] Fig. 5 shows an embodiment of a control of the oscillation of the optical arrangement.

[0066] Fig. 6 shows waveforms of the optical arrangement.

[0067] Fig. 7 shows a magnetic coil with a parallel capacitor.

[0068] Fig. 8 shows two magnetic coils with a parallel capacitor.

[0069] Fig. 9 shows a third embodiment of an optical arrangement.

[0070] Fig. 10 shows a fourth embodiment of an optical arrangement.

[0071] Fig. 11 shows a fifth embodiment of an optical arrangement.

[0072] Examples of implementation

[0073] The invention is explained below using exemplary embodiments.

[0074] Fig. 1 shows the principle of an optical arrangement. The optical arrangement 1 comprises a carrier 7. In the principle diagram in Fig. 1, the function of the carrier 7 is shown as a fixed bearing for one end of the return spring 16. The time-dependent drive force Fd(t) with the reference numeral 9 acts on the other end of the return spring. The oscillating element 13 is guided displaceably in the z direction by means of a linear guide 6. The oscillating element 13 is connected to the mount 5 so that the latter, together with the optical component 2, can also be displaced in the z direction. The combined mass of the oscillating element 13, the mount 5, and the optical component 2, in conjunction with the spring constant of the return spring 16, can form a mechanical oscillating system. The carrier 7, acting as a fixed bearing, must transmit the bearing force F g (t) at the supported end of the return spring.

[0075] Fig. 2 shows a first embodiment. In the first embodiment according to Fig. 2, this is shown as a base plate. The return spring 16 is designed as a contactless magnetic spring. For this purpose, a first permanent magnetic element 18 is provided, which is arranged in a magnetic coupling 22 with a second permanent magnetic element 19. Opposing similar magnetic poles, between which a first repulsive force develops, are each shown here in equally filled black. In addition, the other magnetic pole of the second permanent magnetic element 19, shown not filled in, is opposite a similar pole of a third permanent magnetic element 20, whereby a second repulsive force develops between the second 19 and third permanent magnetic element 20.Since the first and second repulsive forces are oppositely directed and depend on the respective distance between the permanent magnetic elements, the first to third permanent magnetic elements 18, 19, 20 form a return spring 16 without mechanical contact. The return force can, particularly due to the dipole nature of the permanent magnetic elements, increase disproportionately depending on the elongation, i.e., the instantaneous position of the second permanent magnetic element 18. As the second permanent magnetic element 18 approaches the first permanent magnetic element 18 or the third permanent magnetic element 20, the magnitude of the return force exceeds the value that would be present with a return force linearly dependent on the elongation. In this example, the second permanent magnetic element 19 simultaneously functions as an oscillating element 13.As a permanent magnet, it also represents a ferromagnetic element 10, which, in cooperation with the magnetic coil 11, can exert a force in a direction of movement 14. The magnetic coil is provided here as a stator 15, i.e., it is firmly connected to the carrier 7. Likewise, the first and third permanent-magnetic elements 18, 20 are firmly connected to the carrier. The electrically operable linear drive element 8 comprises the magnetic coil 11 and the ferromagnetic element 10. The first permanent-magnetic element 18 and the third permanent-magnetic element 20 are designed as ring magnets in this example.

[0076] As a result, the drive force 9 of the linear drive element 8 can be transmitted to the mount 5 on the coil axis 12. A fixed mechanical connection, such as a push rod, is provided for this purpose. Furthermore, an optical component 2 with an optical axis 4 is provided, which is mounted on the mount 5. In particular, the optical component 2 can comprise at least one of the following elements: a plane mirror

[0077] • a curved mirror

[0078] • an optical lens

[0079] • an optical lens group,

[0080] • a light source

[0081] • an image sensor

[0082] The oscillating element 13 is mounted so as to be displaceable relative to the stator 15 in a direction of movement 14. A linear guide 6 is provided for this purpose.

[0083] The linear drive element 8 is intended to cause the mount 5 with the optical component 2 to oscillate linearly in the direction of movement 14.

[0084] The return spring 16 is intended to provide a restoring force between the oscillating element 13 and the stator 15 in order to form a mechanically oscillatable system.

[0085] The optical arrangement 1 has a resonance frequency f r The linear drive element 8 is operable in such a way that the mechanical oscillation into which the optical arrangement is set has an oscillation frequency f which corresponds to the resonance frequency f r corresponds.

[0086] Advantageously, the optical arrangement 1 can have a damping factor D, with the quality factor Q=1 / (2*D) being between 5 and 10,000, in particular between 10 and 1,000, in particular between 20 and 100. The damping can be achieved, for example, by frictional forces of the linear guide. It is also possible to additionally use a shock absorber to achieve a defined damping.

[0087] Optionally, the arrangement can advantageously comprise at least one sensor 26, 27. In particular, the sensor can have or be designed as a magnetic field sensor, a coil, a position sensor or a light barrier. The sensor can be provided to determine a position of the optical component 2 and / or a speed of the optical component. For this purpose, the sensor can detect the position or speed of the oscillating element 13 or the mount 5 relative to the carrier 7. In the illustration, the first sensor 26 and the second sensor 27 are mechanically connected to the carrier 7. It is also possible for the sensor to detect the position or speed of the optical component 5 if it is attached at a suitable location. The sensor signal can be used to synchronize the periodic electrical energy for operating the linear drive element 8 with the oscillation of the optical component 2.For this purpose, the sensor signal can be amplified and, if necessary, phase-shifted to control the electrical drive energy of the linear drive element 8.

[0088] In a modification of all embodiments, not shown in the figures, the linear drive element 8 is designed such that a ferromagnetic element 10 forms the stator 15, ie is firmly connected to the carrier 7, while the coil 11 represents the oscillating element 13, ie is mechanically connected to the socket 5.

[0089] In the further embodiments, the reference symbols introduced here continue to apply accordingly.

[0090] Fig. 3 shows the principle of an optical arrangement with compensated bearing force. Here, compensation of the force on the bearing 7 is provided. The compensation arrangement 24 comprises a compensation return spring 16a, a compensation oscillating element 13a, a compensation magnetic coil 15a, a compensation linear guide 6a, and a compensating mass 25. The compensating mass is set in oscillation in the opposite direction to the mount 5 by means of a further linear drive element 13a, 15a) by means of a compensation drive force Fk(t) into an oscillation in phase opposition to the oscillation of the optical component in order to generate a resulting bearing force F g (t) = 0.

[0091] Fig. 4 shows a second embodiment. In this example, the optical arrangement 1 is shown with the compensation arrangement 24. The compensating mass 25 is selected here such that it corresponds to the sum of the masses of the mount and the optical component 5. The compensation spring 18a, 19a, 20a is selected in a similar way to the return spring 18, 19, 20, as explained above with reference to Fig. 2. A first permanent-magnetic compensation element 18a is provided as the compensation return spring, which is arranged in a magnetic coupling 22 with a second permanent-magnetic compensation element 19a. Opposing magnetic poles of the same type, between which a first repulsive force develops, are each shown in the same solid black.In addition, the other magnetic pole of the second permanent magnetic compensation element 19a, which is not shown in a filled-in form, is opposed by a similar pole of a third permanent magnetic compensation element 20a, whereby a second repulsive force is formed between the second 19a and third permanent magnetic compensation element 20a.

[0092] Fig. 5 shows an embodiment of a control of the oscillation of the optical arrangement. The optical arrangement here has a control unit 28, wherein the arrangement with the control unit 28 forms a control loop with which the oscillation frequency f is adjusted to the resonance frequency f ris controllable. For this purpose, the sensor signal 5 is fed to the control unit 28 as an actual value 31. The control unit 28 controls the linear drive element 8 by means of a drive signal 9, so that a controlled system with electrical feedback is formed. A setpoint 30 can be provided by an optional function generator 32, which is compared in the control unit with the actual value 31 from the sensor. Alternatively, the control to the resonant frequency can be achieved without a setpoint specification in the sense of a self-oscillating oscillator, solely by the feedback sensor signal.

[0093] Fig. 6 shows oscillation shapes of the optical arrangement. Shown is a sine oscillation 37 of the z-coordinate of the optical component, normalized to the amplitude S, over time t, normalized to the period T. For some applications, a triangular oscillation 38 can be ideally aimed for. In particular, if an image is to be recorded at equidistant points of the z coordinate, the images can be recorded at equidistant times in the case of a triangular oscillation. Shown is a triangular oscillation 38 which has the same frequency, amplitude, and phase as the sine oscillation 37. However, an ideal triangular oscillation is difficult to achieve. By exciting the magnetic coil with a triangular voltage oscillation shape, an optimized oscillation shape 39 can be achieved which lies between the sine oscillation 37 and the ideal triangular oscillation 38.

[0094] Fig. 7 shows a magnetic coil with a parallel capacitor. Here, the linear drive element 8 comprises a magnetic coil 11. A capacitor 40 is connected in parallel with the coil 11, which serves to tune an electrical resonance frequency to a mechanical resonance frequency of the optical arrangement 1.

[0095] Fig. 8 shows two magnetic coils with a parallel capacitor. Here, the magnetic coil 11 of the linear drive element and the magnetic coil 11a of the compensation arrangement are connected in series and connected in parallel with a capacitor 40. Fig. 9 shows a third embodiment of an optical arrangement. Here, the optical component 2 comprises a plurality of lenses 2a, 2b. The optical arrangement 1 can advantageously be used to periodically adjust a focus position of the optical component 2 along the optical axis 4. In this case, an object (in the sense of an observation object) 33 can be imaged onto an image sensor 34. The periodic movement of the optical component 2 changes the focus position, i.e. the distance of the optical component from the image sensor 34. As a result, different planes of the object 33 are successively imaged sharply onto the image sensor. Images recorded one after the other can thus represent a z-stack.A second sensor 27 can be used to determine the current position of the mount 5 in order to trigger an image recording with the image sensor 34 at predetermined positions.

[0096] In this example, the first 18, the second 19, and the third permanent magnetic element 20 form a contactless return spring. Here, the oscillating element 13 is designed as a ferromagnetic element 10 as a separate component, which is not identical to the second permanent magnetic element 19. Since identical magnetic poles face each other, a repulsive magnetic coupling 22 is created. The first and third permanent magnetic elements 18, 20 are connected to the carrier, while the second permanent magnetic element 19 is connected to the socket 5. Since the second permanent magnetic element 19 experiences a distance-dependent repulsive force on both sides, a force-free position of the return spring 16 exists in the center. The ferromagnetic element 10 can, but does not have to, be permanently magnetic. Here, too, the magnetic coil 11 forms the stator 15 of the linear drive element 8.The first sensor 26 can be used to resonantly control the linear drive element 8.

[0097] In a modification, the optical component whose position is periodically adjusted can be the image sensor. In this case, the image sensor is arranged on the mount, and the lenses are fixed. Such an arrangement is shown below in the fifth embodiment.

[0098] Fig. 10 shows a fourth embodiment of an optical arrangement. Here, it is shown how the spring 16 of the first embodiment can be combined with the arrangement of the third embodiment. It is also shown that the optical imaging can be realized with a single lens as the optical component 2. Fig. 11 shows a fifth embodiment of an optical arrangement. In this example, the optical component 2 is embodied as an image sensor 34. The second sensor 27 can be embodied as a proximity sensor. It can also be embodied as an optical encoder, for example if a scale is attached to the horizontal part of the mount 5.

[0099] This example also shows that the spring can comprise four permanent magnetic elements 18, 19, 20, 21. There is a magnetic coupling between the first 18 and second 19 as well as between the third 20 and fourth permanent magnetic element 21.

[0100] 22.

[0101] The reference symbols used consistently in all figures are as follows:

[0102] 1. Optical arrangement

[0103] 2. Optical component

[0104] 3. additional optical component (fixed)

[0105] 4. Optical axis

[0106] 5th version

[0107] 6. Linear guide

[0108] 7. Carrier

[0109] 8. Linear drive element

[0110] 9. Driving force

[0111] 10. Ferromagnetic element

[0112] 11. Solenoid coil

[0113] 12. Coil axis

[0114] 13. Oscillating element

[0115] 14. Direction of movement

[0116] 15. Stator

[0117] 16. Return spring, contactless spring

[0118] 17. Permanent magnetic element

[0119] 18. First permanent magnetic element

[0120] 19. Second permanent magnetic element

[0121] 20. Third permanent magnetic element

[0122] 21. Fourth permanent magnetic element

[0123] 22. Magnetic coupling

[0124] 23. Restoring force 24. Compensation arrangement

[0125] 25. Leveling compound

[0126] 26. First sensor

[0127] 27. Second sensor 28. Control unit

[0128] 29. Drive signal

[0129] 30. Setpoint

[0130] 31. Actual value

[0131] 32. Function generator 33. Object

[0132] 34. Image sensor

[0133] 35. Beam of light

[0134] 36. Central ray

[0135] 37. Sine wave 38. Triangular wave

[0136] 39. Optimized waveform

[0137] 40. Capacitor

Claims

Patent claims 1. Optical arrangement (1) comprising • a carrier (7) • an optical component (2) mounted with a mount (5), in particular wherein the optical component (2) comprises at least one of the following elements: • a plane mirror • a curved mirror • an optical lens • an optical lens group, • a light source • an image sensor • at least one electrically operable linear drive element (8) with an oscillating element (13) and a stator (15), • at least one return spring (16), wherein • the stator (15) is mechanically connected to the carrier (7), • the socket (5) is mechanically connected to the oscillating element (13), • the oscillating element (13) is mounted so as to be displaceable relative to the stator (15) in a direction of movement (14), • the linear drive element (8) is provided to set the mount (5) with the optical component (2) into a linear oscillation in the direction of movement (14), • The return spring (16) is provided to provide a restoring force between the oscillating element (13) and the stator (15), wherein the return spring (16) is designed as a magnet arrangement comprising a first permanent magnetic element (18) and a second permanent magnetic element (19), wherein a repulsive magnetic coupling (22) exists between the first permanent magnetic element (18) and the second permanent magnetic element (19). the optical arrangement (1) has a resonant frequency f r the linear drive element (8) is operable such that the mechanical oscillation has an oscillation frequency f which corresponds to the resonance frequency f r corresponds.

2. Optical arrangement (1) according to claim 1, wherein the arrangement further comprises an attenuation with an attenuation degree D, wherein the quality factor Q=1 / (2*D) is between 5 and 10000, in particular between 10 and 1000, in particular between 20 and 100.

3. Optical arrangement (1) according to one of the preceding claims, wherein the arrangement comprises at least one sensor (26, 27) (in particular magnetic field sensor, coil, position sensor, light barrier).

4. Optical arrangement (1) according to one of the preceding claims, wherein the arrangement further comprises a control unit (28) and the arrangement forms a control loop with the control unit (28) with which the oscillation frequency f to the resonance frequency f r is adjustable.

5. Optical arrangement (1) according to one of the preceding claims, wherein the return spring (16) has a disproportionate dependence of the restoring force on the elongation.

6. Optical arrangement (1) according to claim 5, wherein the resonance frequency f r can be tuned by varying the amplitude of the linear oscillation in a frequency range.

7. Optical arrangement (1) according to one of the preceding claims, wherein the oscillation element has an amplitude of 1 mm to 20 mm, in particular 2 mm to 10 mm, measured from the smallest to the largest deflection value (peak-to-peak value), and / or a resonance frequency f r between 5Hz and 60Hz, especially between 7.5Hz and 30Hz.

8. Optical arrangement (1) according to one of the preceding claims, wherein the linear drive element comprises a coil and a capacitor (40) is connected in parallel with the coil, which capacitor serves to tune an electrical resonance frequency to a mechanical resonance frequency of the optical arrangement (1).

9. Use of an optical arrangement (1) according to one of the preceding claims for periodically adjusting a focus position of the optical component (2).

10. Method for setting an optical component (2) mounted with a mount (5) into a periodic linear oscillation, comprising the following steps: • Providing a periodic electrical drive signal (29) with several periods, • Supplying the periodic electrical drive signal (29) to an electrically operable linear drive element (8), wherein the linear drive element (8) causes a driving force on the socket (5), wherein a position of the socket (5) relative to a carrier (7) changes periodically, • Applying a restoring force dependent on the position of the socket (5) by means of a restoring spring (16), wherein the restoring spring (16) is designed as a magnet arrangement comprising a first permanent magnetic element (18) and a second permanent magnetic element (19), wherein a repulsive magnetic coupling (22) exists between the first permanent magnetic element (18) and the second permanent magnetic element (19). • Continuously recording a measured value of the position of the socket (5) and / or the instantaneous speed of the socket (5) by means of a first sensor (26), • Feeding the measured value to a control unit (28), • Regulating the periodic electrical drive signal (29) to a resonance frequency of the optical arrangement by means of the control unit (28) and / or tuning the resonance frequency of the optical arrangement to a desired frequency by adjusting the amplitude of the oscillation of the optical component (2).

11. The method according to claim 10, wherein the oscillation of the optical component is a sinusoidal oscillation or an optimized oscillation form (39) whose temporal course lies between a sinusoidal oscillation (37) and a triangular oscillation (38) of the same amplitude.

12. Method according to claim 10 or 11 further comprising • imaging an object (33) onto an image sensor (34) by means of the optical component (2), wherein, depending on the position of the mount (5), a plane on the object side is sharply imaged onto the image sensor (34), • Continuous recording of several images at different positions of the mount (5) using the image sensor (34).

13. Method according to claim 12, wherein during the continuous recording of the images, an image recording is triggered at a specific position of the frame (5).

14. Method according to claim 12 to 13, further comprising • Forming a z-stack from several of the acquired images of a period • Creating a two-dimensional image of increased depth of field from the z stack and / or creating a three-dimensional model of the object from the z stack.

15. The method of claim 12 to 14, further comprising: producing a two-dimensional or three-dimensional video from a plurality of successively produced two-dimensional images or three-dimensional models.

Images