OPTOELECTRONIC DEVICE

Abstract

An optoelectronic device comprises a printed circuit board having at least a first printed circuit board section, a separate second printed circuit board section, and a flexible connecting section, wherein at least the first printed circuit board section is rigid. The second printed circuit board section is mechanically connected to the first printed circuit board section via the flexible connecting section, wherein respective contact elements of the first printed circuit board section and the second printed circuit board section are electrically connected via conductor tracks of the flexible connecting section. An optical component is arranged on the second printed circuit board section. For adjusting the position of the optical component, the optoelectronic device has a drive for the controlled movement of the second printed circuit board section relative to the first printed circuit board section, deforming the flexible connecting section.

Description

The present invention relates to an optoelectronic device having a printed circuit board which comprises at least a first printed circuit board section, a separate second printed circuit board section and a flexible connecting section, wherein at least the first printed circuit board section is rigid, wherein the second printed circuit board section is in mechanical connection with the first printed circuit board section via the flexible connecting section and respective contact elements of the first printed circuit board section and of the second printed circuit board section are in electrical connection via conductor tracks of the flexible connecting section, and wherein an optical component is arranged on the second printed circuit board section.An optoelectronic device having a plurality of printed circuit board sections and a flexible connecting section is disclosed, for example, in US 2009 / 0223300 A1. The use of a printed circuit board or printed circuit board which has both a rigid and a flexible section enables optimum utilization of the installation space available. In particular, the printed circuit board can be brought into a desired shape by folding.After the assembly of the known optoelectronic device, the shape of the printed circuit board remains unchanged. However, there is a desire to provide optoelectronic devices with movable parts.It is an object of the invention to specify an optoelectronic device of the aforementioned type which is of simple construction and can be used for applications with a movable or moving optical component.The object is achieved by an optoelectronic device having the features of claim 1.According to the invention, the optoelectronic device for a position adjustment of the optical component has a drive for controlled movement of the second printed circuit board section with respect to the first printed circuit board section, deforming the flexible connecting section. It is thus possible to adjust the optical component over a relatively wide travel path, even though it is arranged on the second printed circuit board section, i.e. is integrated into the printed circuit board, for example. It is therefore also not necessary, for example, to provide a complicated separate adjusting device such as a rotating polygonal mirror or a vibrating mirror. Thus, an optoelectronic device according to the invention is simple to produce and easily miniaturizable. The flexible connecting portion of the circuit board not only serves for electrically connecting the contact elements, but can also be used as a joint if necessary. The provision of an independent joint can then be dispensed with, which enables a reduction in the production costs.An optoelectronic device according to the invention can be used, for example, in laser scanners, projectors or cameras.A rigid printed circuit board section is understood to mean a printed circuit board section which is not designed for significant deformation with regard to the selection of material and the design. It is understood that such circuit board sections can nevertheless be deformed to a small extent and / or for a short transition time during handling. For example, each rigid printed circuit board section of an optoelectronic device according to the invention can comprise a rigid carrier plate made of a fiber composite material. The thickness of the carrier plate can be at least 1 mm. The flexible connecting section, on the other hand, is designed for a significant deformation with regard to the material selection and the design. The flexible connecting section can comprise a polyimide film, in particular a copper-laminated polyimide film. Preferably, the flexible connecting portion is less than 0.1 mm thick.It is preferred that the second printed circuit board section is likewise rigid, because the movement of two rigid components relative to one another is possible with particularly high precision. However, in certain applications, it may be desired that the optical component be disposed on a flexible circuit board portion.The first printed circuit board section can be configured for fastening to a carrier component or to a housing of the optoelectronic device, that is to say can comprise at least one screw hole or the like, for example. The high rigidity of the rigid printed circuit board section facilitates the fastening in this case.In principle, the optical component can be a simple optical component such as a mirror, a filter or a lens. Preferably, however, the optical component is an optoelectronic component which is electrically connected to contact elements of the second printed circuit board section.According to one embodiment of the invention, the optical component is a light transmitter or a light receiver. In particular, a laser diode can be provided as light transmitter. A photodiode, for example an avalanche photodiode (APD) or a photodiode array (imager), can be provided as the light receiver, for example. By adjusting the position of the light transmitter, for example, an emitted light beam can be deflected in a desired manner. The position adjustment of a light receiver enables, for example, a focus adjustment upon the reception of a focused light beam. It is also possible for both a light transmitter and a light receiver to be arranged on the second printed circuit board section. The position adjustment here runs synchronously for both components.One embodiment of the invention provides that the second printed circuit board section has an electrical circuit which comprises a control circuit of the light transmitter or of the light receiver and / or that the first printed circuit board section has an electrical circuit which comprises a signal processing circuit for processing signals of the light transmitter or of the light receiver. The electronics for the operation of the light transmitter and / or of the light receiver thus do not have to be provided separately, but rather can be integrated into the printed circuit board. This enables further miniaturization.A lens can be arranged on the first circuit board section or on the second circuit board section, which lens deflects light beams emitted by a light transmitter arranged on the other circuit board section as a function of an impact point. The lens converts lateral translation movements of the input beam into angular changes of the output beam. In many cases, it is easier to shift the second printed circuit board section instead of tilting it. The lens can nevertheless provide a beam deflection, as is required, for example, in scanners.A further embodiment of the invention provides that a light transmitter is arranged on a front side of the second printed circuit board section and a light receiver is arranged on an opposite rear side of the second printed circuit board section, or vice versa. By a movement of the second printed circuit board section, the transmission path and the reception path are adjusted equally. It can also be provided that a lens is arranged on a front side of the first printed circuit board section and a lens having the same effect is arranged on an opposite rear side of the first printed circuit board section. This makes it possible to ensure synchronous angular deflection for the transmission beam and the reception beam.The drive can be designed to displace the second printed circuit board section relative to the first printed circuit board section, preferably by a displacement path of at least 1 mm, particularly preferably by a displacement path of at least 3 mm, further particularly preferably by a displacement path of at least 10 mm. A drive suitable for displacement can be of relatively simple construction.The drive can be configured to displace the second printed circuit board section in a base plane of the first printed circuit board section, parallel to a base plane of the first printed circuit board section or transversely to a base plane of the first printed circuit board section. A displacement transversely to the base plane of the first printed circuit board section is suitable in particular for focus adjustment of a light receiver. If only a displacement in one direction is desired, a particularly simple construction results from the fact that an individual drive and a guide device, i.e. a guide linkage or the like, are provided.Alternatively or additionally to a displacement, the drive can be designed to tilt the second printed circuit board section relative to a base plane of the first printed circuit board section, preferably by a tilt angle of at least 3°, particularly preferably by a tilt angle of at least 7°. Tilting is advantageous in particular in scanner applications, wherein in this case no lens is required for converting a displacement movement into an angular deflection.According to a special embodiment, the second printed circuit board section is rectangular in a plan view, wherein individual actuators of the drive are arranged at three or four corner regions of the second printed circuit board section. The second printed circuit board section carrying the optical component can then be tilted in any desired manner or, with the same deflection of all individual actuators, can also be linearly displaced. If only tilting about a fixed tilting axis is required, an individual actuator in conjunction with a pivot joint is sufficient. For example, a lateral edge of the second circuit board section can project into a pocket arranged on the first circuit board section or can be encompassed by a clamp, as a result of which the pivot joint is formed. The individual actuator can then engage on the opposite edge region.A further embodiment of the invention provides that the first printed circuit board section has a frame-like shape and the second printed circuit board section is arranged in a central cutout of the first printed circuit board section and / or concentrically with respect to a central cutout of the first printed circuit board section. This enables a particularly compact construction.The circuit board may comprise an additional flexible connecting portion via which the second circuit board portion is in mechanical connection with the first circuit board portion, wherein respective first ends of the flexible connecting portions are connected to opposite inner edge regions of the recess and / or respective second ends of the flexible connecting portions are connected to opposite outer edge regions of the second circuit board portion. In this way, the second circuit board section is reliably held on the first circuit board section.In principle, the drive can be an electrostatic, mechanical, pneumatic or hydraulic drive. Preferably, however, the drive comprises an electromagnetic actuator. In particular, an electromagnetic direct drive can be provided. Such actuators are of simple construction and require only little installation space.A special embodiment of the invention provides that the electromagnetic actuator comprises a magnetic coil fastened to the first printed circuit board section or to the second printed circuit board section and a magnetic element interacting with the magnetic coil, which magnetic element is fastened to the other printed circuit board section or to a carrier component of the optoelectronic device. For activation of the actuator, the solenoid coil is to be put under current. This can be effected, for example, via an electronic circuit which is integrated into the first printed circuit board section or into the second printed circuit board section. This enables a particularly simple and compact embodiment.Preferably, the magnetic element is a permanent magnet. A current supply is then only required for one component of the electromagnetic actuator. In principle, however, a further magnetic coil could also be provided as the magnetic element. If necessary, each of the provided solenoids may include an iron core. According to a special embodiment of the invention, the electromagnetic drive comprises a voice coil motor.A further embodiment of the invention provides that the electromagnetic actuator comprises a magnet which generates a magnetic field oriented transversely to a base plane of the first printed circuit board section and interacts with at least one conductor track of the second printed circuit board section in order to induce a Lorentz force on the second printed circuit board section. When current flows in the conductive path, the second circuit board section is moved in the fixed magnetic field due to the Lorentz force. In this case, a plurality of parallel conductor tracks can reinforce the Lorentz force. By reversing the current direction, the relevant printed circuit board section can be moved in the reverse direction. Moreover, conductor tracks running at right angles to one another can be provided in order to enable deflection of the second printed circuit board section in different directions. In this embodiment, a magnetic coil does not necessarily have to be provided.In order to ensure exact control or regulation of the movement of the second printed circuit board section, the drive can comprise a sensor for determining the deflection of the second printed circuit board section with respect to the first printed circuit board section.An optoelectronic device according to the invention can also comprise an inertial measurement unit (IMU), wherein a control circuit of the optoelectronic device is configured to perform the position adjustment of the optical component such that mechanical influences from the outside are compensated. In this way, for example, shake protection for image sensors can be provided.Further developments of the invention can also be taken from the dependent claims, the following description and the attached drawings.The invention will be described below by way of example with reference to the drawings. FIG. 1 is a plan view of an optoelectronic device according to a first embodiment of the invention. FIG. 2 shows the optoelectronic device according to FIG. 1 in a lateral sectional view. FIG. 3 is a plan view of an optoelectronic device according to a second embodiment of the invention. FIG. 4 shows an optoelectronic device according to a third embodiment of the invention from the side. FIG. 5 is a perspective view of an optoelectronic device according to a fourth embodiment of the invention.The optoelectronic device 11 shown in FIGS. 1 and 2 and configured according to a first embodiment of the invention comprises a printed circuit board or printed circuit board 13 which comprises a first printed circuit board section 17 and a second printed circuit board section 19 separate therefrom. Both circuit board sections 17, 19 comprise rigid carrier plates, for example made of a fiber-reinforced plastic. As shown, the first printed circuit board section 17 is configured frame-like and has a central cutout 21. The second printed circuit board section 19 is arranged centrally within the central cutout 21.Here, the second circuit board section 19 is in mechanical connection with the first circuit board section 17 via two flexible connecting sections 23, 24. The flexible connecting portions 23, 24 preferably comprise a copper-clad polyimide film having a thickness of 0.1 mm or less and thus being easily deformable. Conductor tracks 25 of the flexible connecting sections 23, 24 serve for the electrical connection of contact elements, not shown, of the first printed circuit board section 17 and of the second printed circuit board section 19.In principle, the second printed circuit board section 19 could also be mechanically connected to the first printed circuit board section 17 via three or more flexible connecting sections 23, 24.The second printed circuit board section 19 is equipped with an optical component, here in the form of a light receiver 27. For example, the light receiver 27 can be designed as a photodiode. The light receiver 27 is preferably electrically connected to contact elements of the second printed circuit board section 19. On the second printed circuit board section 19 an electrical circuit can also be provided, which comprises, for example, a control circuit and / or an evaluation circuit of the light receiver 27. In addition, a signal processing circuit for processing signals of the light receiver 27 can be provided, for example, on the first printed circuit board section 17. The electronic circuits can also be distributed over the printed circuit board sections 17, 19. In certain applications, electrical circuits of the optoelectronic device 11 or parts thereof can also be provided on the flexible connecting sections 23, 24.As can be seen in FIG. 2, the light receiver 27 is located in the focus of a converging lens 29 during operation of the optoelectronic device 11. Therefore, the optoelectronic device 11 is provided with a drive 30 which is capable of moving the second printed circuit board section 19 with respect to the first printed circuit board section 17, wherein the two flexible connecting sections 23, 24 deform during the movement. In the embodiment shown in FIGS. 1 and 2, the movement takes place exclusively linearly in a displacement direction pointing transversely to a base plane 33 of the first printed circuit board section 17. A simple electromagnetic drive 30 is sufficient for this purpose, which comprises, for example, an actuator 66 having a magnetic coil 35 arranged on the first printed circuit board section 17 and a permanent magnet 37 arranged on the second printed circuit board section 19. For displacement of the second circuit board section 19, the magnet coil 35 is energized so that it attracts or repels the permanent magnet 37. The magnetic coil 35 is arranged here (in the illustration of FIG. 2 ) below the permanent magnet 37. In this way, when the magnet coil 35 is wound in such a way that the magnetic field lines in FIG. 2 are aligned vertically, the greatest possible part of the field strength is used. However, various geometric arrangements are possible for the magnet coil 35 and the permanent magnet 37. A preferred configuration is the embodiment of the drive 30 as a voice coil motor (voice coil motor). The magnet coil 35 can be surrounded in particular by a pot magnet. In the event of a current flowing through the magnet coil 35, the latter is then drawn into the pot magnet or pressed out of the latter depending on the polarity.In order to ensure an exact movement, the second printed circuit board section 19 can be guided on the first printed circuit board section 17 by means of a guide device. For example, a slide rail arrangement can be provided as a guide device. If tilting of the second printed circuit board section 19 relative to the first printed circuit board section 17 is also desired, three electromagnetic actuators could act on respective corner regions 39 (FIG. 1 ) of the second printed circuit board section 19.FIG. 3 shows a second embodiment of an optoelectronic device 41 according to the invention. However, no light receiver is provided here as the optical component, but a light transmitter 47, for example an edge emitter. This is electrically connected to contact elements of the second printed circuit board section 19 and is connected via these to a control circuit, which is preferably integrated into the second printed circuit board section 19.The light emitter 47 emits parallel to the surface of the second printed circuit board section 19. A deflecting lens 49, which is designed here as a converging lens, is fastened to the first printed circuit board section 17. Depending on the point of the entry surface of the deflection lens 49 at which the light beam of the light transmitter 47 impinges, different deflection angles result for the light beam. Thus, by moving the second printed circuit board section 19 relative to the first printed circuit board section 17, for example according to FIG. 3 transversely to the paper plane, a variable beam deflection can be achieved, as is desired in particular for laser scanners.The third embodiment of an optoelectronic device 51 shown in FIG. 4 differs from the above-described embodiments in that the printed circuit board 13 has only one flexible connecting section 23. Two edge regions 53 of the first printed circuit board section 17 and of the second printed circuit board section 19 are connected to one another mechanically via said first edge region. On the side facing away from the flexible connecting portion 23, the second printed circuit board portion 19 is accommodated in a pocket 57 made of metal or plastic, as a result of which a pivot bearing is formed. The second printed circuit board section 19 can thus be tilted with respect to the first printed circuit board section 17 in a particularly simple manner, for which only a single actuator 67 acting on the edge regions 53 is required, which actuator forms the drive 30 here.FIG. 5 shows a further embodiment of an optoelectronic device 61 which is configured similarly to the optoelectronic device 11 according to the first embodiment, wherein however the central cutout 21 of the first printed circuit board section 17 is smaller than the second printed circuit board section 19. The second printed circuit board section 19 could also be arranged laterally offset with respect to the central cutout 21. FIG. 5 also shows, by way of example, contact elements 65 of the printed circuit board 13. In order to facilitate the production of the first printed circuit board section 17 provided with the central cutout, it can be joined together from two parts, as is illustrated by dashed lines in FIG. 5.In an embodiment of the invention which is not shown, the second printed circuit board section 19 is located in the substantially homogeneous magnetic field of a permanent magnet. The movement of the second printed circuit board section 19 is caused by the Lorentz force which occurs when an electric current flows through a conductor track of the second printed circuit board section 19 oriented transversely to the magnetic field. As a result of the Lorentz force, a displacement of the second printed circuit board section 19 results.It has been found that travel paths up to the centimeter range are possible by means of a simple electromagnetic actuator. Due to the elasticity of the flexible connecting section 23, a spring force results which can be used in an advantageous manner. In principle, permanent magnets can be used instead of an iron core, wherein the magnetic field can be attenuated or amplified by the current flowing through the coil. In this way, it is possible to provide a prestress, so that an equilibrium of forces is established in the non-energized state. This is advantageous in particular in the case of mechanical vibrations, because in this way a vibration in both directions is possible. In a further embodiment, a non-magnetized iron core protrudes into a coil. The iron core is then pulled into the coil or pressed outwards depending on the current flow direction.Because the flexible connecting sections 23, 24 are used for movably mounting the second printed circuit board section 19 on the first printed circuit board section 17, it is possible to dispense with large and costly bearing units or joints and there are a wide variety of possibilities for miniaturization. Active optical components such as light emitter 47 and light receiver 27 can be spatially moved over considerable distances.List of reference characters11 Optoelectronic device 13 Printed circuit board 17 First printed circuit board section 19 Second printed circuit board section 21 Central cutout 23 Flexible connecting section 24 Flexible connecting section 25 Conductor track 27 Light receiver 29 Converging lens 30 Drive 33 Base plane 35 Magnet coil 37 Permanent magnet 39 Corner region 41 Optoelectronic device 47 Light transmitter 49 Deflection lens 51 Optoelectronic device 53 Edge region 57 Pocket 61 Optoelectronic device 65 Contact element 66, 67 ActuatorReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedUS 2009 / 0223300 A1

[0002]

Claims

Optoelectronic device (11, 41, 51, 61) having a printed circuit board (13) which comprises at least a first printed circuit board section (17), a separate second printed circuit board section (19) and a flexible connecting section (23, 24), wherein at least the first printed circuit board section (17) is rigid, wherein the second printed circuit board section (19) is in mechanical connection with the first printed circuit board section (17) via the flexible connecting section (23, 24) and respective contact elements (65) of the first printed circuit board section (17) and of the second printed circuit board section (19) are in electrical connection via conductor tracks (25) of the flexible connecting section (23, 24), wherein an optical component (27, 47) is arranged on the second printed circuit board section (19), and wherein the optoelectronic device (11, 41, 51, 61) is for a position adjustment of the optical component (27, 27, 47) has a drive (30) for controlled movement of the second printed circuit board section (19) with respect to the first printed circuit board section (17), deforming the flexible connecting section (23, 24).Optoelectronic device according to claim 1, wherein the optical component (27, 47) is an optoelectronic component which is electrically connected to contact elements (65) of the second printed circuit board section (19).Optoelectronic device according to claim 1 or 2, wherein the optical component is a light transmitter (47) or a light receiver (27).Optoelectronic device according to claim 3, wherein the second printed circuit board section (19) has an electrical circuit which comprises a control circuit of the light transmitter (47) or of the light receiver (27), and / or wherein the first printed circuit board section (17) has an electrical circuit which comprises a signal processing circuit for processing signals of the light transmitter (47) or of the light receiver (27).Optoelectronic device according to claim 3 or 4, wherein a lens (49) is arranged on the first printed circuit board section (17) or on the second printed circuit board section (19), which lens deflects light beams emitted by a light transmitter (47) arranged on the other printed circuit board section (17, 19) as a function of an impact point.Optoelectronic device according to one of claims 3 to 5, wherein a light transmitter (47) is arranged on a front side of the second printed circuit board section (19) and a light receiver (27) is arranged on an opposite rear side of the second printed circuit board section (19), or vice versa.Optoelectronic device according to one of the preceding claims, wherein the drive (30) is configured to displace the second printed circuit board section (19) relative to the first printed circuit board section (17), preferably by a displacement path of at least 1 mm, particularly preferably by a displacement path of at least 3 mm, further particularly preferably by a displacement path of at least 10 mm.Optoelectronic device according to claim 7, wherein the drive (30) is configured to displace the second printed circuit board section (19) in a base plane (33) of the first printed circuit board section (17), parallel to a base plane (33) of the first printed circuit board section (17) or transversely to a base plane (33) of the first printed circuit board section (17).Optoelectronic device according to one of the preceding claims, wherein the drive (30) is configured to tilt the second printed circuit board section (19) with respect to a base plane (33) of the first printed circuit board section (17), preferably by a tilt angle of at least 3°, particularly preferably by a tilt angle of at least 7°.Optoelectronic device according to one of the preceding claims, wherein the first printed circuit board section (17) has a frame-like shape and the second printed circuit board section (19) is arranged in a central cutout (21) of the first printed circuit board section (17) and / or concentrically with respect to a central cutout (21) of the first printed circuit board section (17).Optoelectronic device according to claim 10, wherein the printed circuit board (13) comprises an additional flexible connecting portion (23, 24) via which the second printed circuit board portion (19) is in mechanical connection with the first printed circuit board portion (17), wherein respective first ends of the flexible connecting portions (23, 24) are connected to opposite inner edge regions of the cutout (21) and / or respective second ends of the flexible connecting portions (23, 24) are connected to opposite outer edge regions of the second printed circuit board portion (19).Optoelectronic device according to one of the preceding claims, wherein the drive (30) comprises an electromagnetic actuator (66, 67).Optoelectronic device according to claim 12, wherein the electromagnetic actuator (66) comprises a magnetic coil (35) fastened to the first printed circuit board section (17) or to the second printed circuit board section (19) and a magnetic element (37) interacting with the magnetic coil (35), which magnetic element is fastened to the other printed circuit board section (17, 19) or to a carrier component of the optoelectronic device (11, 41, 51, 61).The optoelectronic device according to claim 13, wherein the magnetic element (37) is a permanent magnet.Optoelectronic device according to one of claims 12 to 14, wherein the electromagnetic actuator comprises a magnet which generates a magnetic field oriented transversely to a base plane (33) of the first printed circuit board section (17), which magnetic field interacts with at least one conductor track (25) of the second printed circuit board section (19) in order to induce a Lorentz force on the second printed circuit board section (19).

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