Optical accessories and camera system

Abstract

Optical accessory (200) that is to be temporarily coupled to a surface of a separate machine vision device (100) along a camera axis (108) of an imaging device of the machine vision device (100), the optical accessory (200) comprising: a structural base (206) having a first surface and a central viewing area through which the machine vision device (100) can view a field of view; at least one mounting element (210) extending from a second surface of the structural base (206) to engage with a surface of the separate machine vision device (100), wherein the at least one mounting element (210) is dimensioned to have a length sufficient so that, when installed, the structural base (206) is positioned at a distance in front of a lens (204, 406) of the separate machine vision device (100); and a magnetic element (214, 412) arranged at a distal end of the at least one mounting element (210), wherein the magnetic element (214, 412) generates a magnetic retention force that secures the optical accessory (200) to a surface of the machine vision device (100).

Description

Technical field

[0001] This disclosure relates to an optical accessory and a camera system. background

[0002] Machine vision systems can use image capture devices, such as an electronic imaging device (e.g., a CMOS or CCD camera sensor), to record images of objects or coded symbols affixed to the objects, including, for example, barcodes, data matrices, and other symbols. The recorded image can then be processed using an identification algorithm to decode the pattern provided by the image or symbol in order to obtain data about the object to which the image or symbol is attached. These devices are used in both retail and manufacturing environments for providing pricing information for objects or goods, monitoring and maintaining inventory, and tracking industrial parts.Machine vision systems can include one of several different optical accessories that can be used to adjust or modify the recorded images. In some cases, optical accessories can be mounted (e.g., temporarily secured) to parts of the machine vision system.

[0003] For example, effective detection and processing of an encoded symbol by the machine vision system typically requires that the object containing the symbol be appropriately illuminated. Effective illumination may require one or more types of lighting to be positioned on or near the machine vision system.

[0004] Other types of optical accessories can also be used.

[0005] US patent 5208624A reveals a camera lens with a filter adapter assembly.

[0006] US 2010 / 0 176 319 A1 reveals a modular focus system for image-based code readers. Summary of the invention

[0007] The invention is defined in the independent claims. Advantageous embodiments are defined in the dependent claims.

[0008] In some aspects, an optical accessory may include a camera illumination module capable of positioning at least one illumination element relative to a lens of the machine vision system. The illumination module may include a structural base (e.g., an illumination plate) having a first surface and incorporating at least one illumination element arranged along the first surface, and at least one mounting element extending from a second surface of the illumination plate; and a magnetic element located at a distal end of one of the at least mounting elements. The magnetic element may be configured to (i) be received along a surface of the machine vision device; and (ii) generate a magnetic retention force suitable for securing the illumination module to the surface of the machine vision device.

[0009] In some aspects, a machine vision system for imaging an inspection field may include a camera comprising a housing that defines a camera axis; a lens arranged within a lens container along the camera axis; and an optical accessory. The optical accessory may include a structural base having a first surface; at least one mounting element extending from a second surface of the structural base; and a magnetic element located at a distal end of one of the at least one mounting element. The magnetic element may (i) be received along a surface of the housing, and (ii) generate a magnetic retention force suitable for securing the optical accessory to the surface of the housing.

[0010] In some aspects, an optical accessory may include an additional lens device for coupling to a surface of a machine vision device along a camera axis along an imaging device of the machine vision device. The additional lens device may include a lens module configured to be removably attached to a lens of the imaging device; and a magnetic element arranged in or on the lens module, the magnetic element being configured to generate a magnetic retention force to secure the lens module to a surface of the machine vision device.

[0011] In some aspects, a camera system may include a camera enclosure; a lens arranged in or along the camera enclosure along an optical axis of the camera system; and an optical accessory attached to the camera enclosure, the optical accessory being secured using a magnetic retention force provided by at least one magnetic element.

[0012] In some aspects, a machine vision system for illuminating and imaging an inspection field may include a camera device comprising a housing which includes an imaging device defining a camera axis, and a control unit connected to the imaging device, wherein the housing defines a lens container along the camera axis; a lens arranged within the lens container; a first optical accessory (e.g., an additional lens device) coupled to the lens along the camera axis; and a second optical accessory (e.g., an illumination module) coupled to the camera device or the additional lens device.The additional lens device may include a lens module configured to be removably connected to the lens; and a first magnetic element arranged in or on the lens module, the first magnetic element being configured to generate a magnetic retention force to secure the lens module to the lens of the imaging device. The illumination module may include a structural base (e.g.,a lighting panel, which has a first surface and includes at least one lighting element arranged along the first surface; at least one mounting element extending from a second surface of the structural base; and a second magnetic element arranged at a distal end of one of the at least one mounting element, wherein the second magnetic element is configured to: (i) be received along a surface of a component of the camera device; and (ii) generate a magnetic retention force suitable for securing the lighting module to the surface of the camera device.

[0013] In some aspects, a method for installing an optical accessory (e.g., an additional lens device) along a camera axis of an imaging device for a machine vision camera system may involve: the additional lens device having a lens arranged in a lens container along the camera axis; arranging a magnetic element in or on the additional lens device; using a magnetic force provided by the magnetic element to couple the additional lens device axially to the lens relative to the camera axis; aligning the additional lens device relative to the lens arranged in the imaging device; and electrically connecting the additional lens device to the machine vision camera system.

[0014] Embodiments may include one or more of the following features.

[0015] In some embodiments, an optical accessory may further include an orientation feature that restricts the orientation of the optical accessory relative to the machine vision device. For example, the at least one mounting element may include a first mounting element and a second mounting element, and the orientation feature may include a size and / or shape of the first mounting element that differs from a size and / or shape of the second mounting element.

[0016] In some embodiments, the alignment feature includes a distal end of the first mounting element having a first cross-sectional shape and a distal end of the second mounting element having a second cross-sectional shape, wherein the first cross-sectional shape is configured to be received in a first container along the surface of the machine vision device and is configured to be prevented from being received in a second container along the surface of the machine vision device, and wherein the second container is configured to receive the second cross-sectional shape.In some cases, the first cross-sectional shape has a first average width and the second cross-sectional shape has a second average width, the first average width being larger than the second average width, so that the distal end of the first assembly element can be received in the first container but not in the second container.

[0017] In some embodiments, the at least one mounting element includes at least two mounting elements, and the alignment feature includes a difference in the angular distance between two adjacent mounting elements relative to a central axis of the optical accessory (e.g., the illumination module).In some cases, the at least two mounting elements include a first mounting element and a second mounting element, wherein the difference in angular distance is a difference between (i) a first angular distance between the first and the second mounting element relative to the central axis of the optical accessory and (ii) a second angular distance between the first and the second mounting element relative to the central axis, wherein the first angular distance and the second angular distance are different regions of a total circumferential area around the central axis, and wherein the difference between the first angular distance and the second angular distance limits the orientations in which the optical accessory can be attached to the machine vision camera device.

[0018] In some embodiments, the magnetic element includes a first magnet, and the alignment feature includes an arrangement of the first magnet relative to the machine vision device. In some cases, the alignment feature includes an arrangement of the magnetic polarity of the first magnet relative to an arrangement of the magnetic polarity of a second magnet located in or on the machine vision device.

[0019] In some embodiments, the at least one mounting element includes an extended element that extends from the second surface of the structural base. In some embodiments, one or more of the mounting elements are arranged at a non-zero-degree angle (e.g., approximately orthogonal) relative to the second surface. In some embodiments, the optical accessory includes three or more extended mounting elements.

[0020] In some embodiments, the optical accessory includes a second magnetic element arranged along the structural base, configured to couple with another (e.g., a second) optical accessory. In some cases, the optical accessory includes the second optical accessory, which is magnetically coupled to the structural base.

[0021] In some embodiments, the optical accessories also include an electrical mounting element that is electrically coupled to the structural base, wherein the electrical mounting element is configured to electrically connect the at least one illumination element to at least one of a power source, a control device, or a signal-generating device of the machine vision device. In some cases, the signal-generating device includes a detection signal-generating device, such as one of several sensors (e.g., a temperature sensor), which is arranged on the structural base.

[0022] In some embodiments, the magnetic element comprises a ferromagnetic element configured to generate the magnetic retention force with a magnet arranged along the surface of the camera device or machine vision system. In some embodiments, the machine vision system or optical accessory may include an electrical mounting element electrically connected to the structural base, wherein the electronic mounting element electronically connects the optical accessory or a component thereof (e.g., the illumination plate or lens module) to at least one power source or control device of the machine vision system. In some embodiments, the electrical mounting element includes an electrical connector providing a wired connection to the structural base.The electrical connector can be configured to connect to the machine vision system. For example, the electrical mounting element can include an electronic contact area along a distal end of one of the at least one mounting element. The electrical contact area can be configured to electrically connect the optical accessory (e.g., the at least one illumination element) to the at least one power source or control device upon contact with a matching electrical contact surface. In some cases, the electrical contact area and the magnetic element are arranged along a distal end of the same mounting element. In some cases, the electrical mounting element includes one or more load-bearing, flexible connecting pins (e.g., spring-loaded contact pins).In some embodiments, the magnetic holding force connects the electrical contact area to the matching electrical contact surface.

[0023] In some embodiments, the optical accessories include a camera lens illumination module, and the structural base includes an illumination plate having at least one illumination element arranged along the first surface. In some embodiments, the lens is generally stationary within the lens housing.

[0024] In some embodiments, the housing includes an imaging device that defines a camera axis and a control unit that is connected to the imaging device.

[0025] In some embodiments, the surface of the machine vision device is a surface of a ferromagnetic retaining element arranged around the lens.

[0026] In some embodiments, the lens module includes an adjustable lens configured to modify an optical property of the machine vision device. For example, the adjustable lens may include a variably adjustable lens (e.g., a liquid lens device).

[0027] In some embodiments, the magnetic element is arranged such that when the lens module is attached to the lens via the magnetic retention force, the lens module is generally fixed axially along the camera axis, and the lens module is able to rotate about the camera axis.

[0028] In some embodiments, a second magnetic element is arranged along the lens module, wherein the second magnetic element is configured to couple with an optical accessory. In some cases, a second optical accessory is magnetically coupled to the lens module.

[0029] In some embodiments, the at least one magnetic element is a component of the optical accessory.

[0030] In some embodiments, the optical accessory includes an alignment feature or a mechanism that restricts an installed orientation of the optical accessory relative to the camera enclosure.

[0031] In some embodiments, the magnetic retention force is generated between a first magnetic element of the at least one magnetic element arranged on the optical accessory and a ferromagnetic retention element arranged on the lens, and in a fixed configuration, the first magnetic element is spaced away from the ferromagnetic element.

[0032] In some embodiments, using the magnetic force provided by the magnetic retaining element to axially couple the additional lens device to the lens involves positioning the magnetic element located on or in the additional lens device close to a ferromagnetic retaining element (e.g., a retaining ring) attached to the lens.

[0033] In some embodiments, the method may also involve adjusting the additional lens to change the focal length of the machine vision camera system.

[0034] As used here, the term magnet is intended to refer to a material or object that generates a magnetic field. This magnetic field contains a force that attracts ferromagnetic materials, such as iron-containing materials (e.g., iron), and attracts or repels other magnets.

[0035] A permanent magnet is typically an object made from a magnetized material, which generates its own magnetic field. Ferromagnetic materials are materials capable of being attracted to a magnet and are typically capable of being magnetized. Some examples of ferromagnetic materials include iron, nickel, cobalt, some rare-earth alloys, and some naturally occurring minerals, such as lodestone.

[0036] Ferromagnetic materials can be divided into magnetically “soft” materials, such as annealed iron, which can be magnetized but does not tend to remain magnetized, and magnetically “hard” materials, which do. Permanent magnets are typically made from hard ferromagnetic materials, such as Alnico and ferrites, which undergo special processing in a strong magnetic field during manufacturing to align their internal microcrystalline structure, making them very difficult to demagnetize.

[0037] Magnets can also contain an electromagnet. An electromagnet typically includes a coil of electrical conductor (e.g., a wire) that generates a magnetic field when an electric current flows through the wire. The coil stops generating the magnetic field when the current is no longer flowing through the wire. In some cases, the coil is wound around a core of ferromagnetic material, such as steel, which amplifies the magnetic field generated by the winding.

[0038] The embodiments may have one or more of the following advantages.

[0039] In some aspects, an optical accessory (e.g., a lighting module or an additional lens device) capable of quickly and easily coupling to a camera device (e.g., a machine vision system) using magnetic force can be attached and removed more quickly and easily than some other optical accessories, such as those connected to camera devices using fasteners or other more complex attachment methods. This advantage is possible because, in some cases, fasteners and other attachment methods require the use of additional tools for installation and removal. For example, if a camera device is mounted in a hard-to-reach location, a person can remove the optical accessory (e.g., a lighting module) simply by pulling it away from the camera device.(with one hand) remove, manually adjust or change the lens (e.g. with the opposite hand), e.g. to adjust the focal length of the camera device and then reattach the optical accessory to the camera device.

[0040] Because it can be attached to, removed from, and reattached to the camera device more quickly and easily, a person (e.g., a mechanic) working on the camera device can remove the optical accessory, adjust the lens, and reinstall the optical accessory more quickly. Faster disassembly and reassembly can reduce maintenance and downtime of the camera device, resulting in shorter downtimes for automated manufacturing, production, or inspection lines where the camera system is used.

[0041] In some aspects, an optical accessory incorporating mounting or alignment features or mechanisms, as described herein, can help prevent the optical accessory from being accidentally attached to the camera device in an incorrect orientation. In some cases, for example, when the optical accessory is a lighting device (e.g., a lighting module), limiting unwanted orientations of the lighting module can help create a proper lighting environment along the field of view based on the needs of the camera device and the environment it is imaging. As a result, the need for repairing or reconstructing a camera device can be reduced, and consequently, downtime for automated manufacturing, production, or inspection lines on which the camera device is used can be minimized. Brief description of the drawings Fig. Figure 1 is a perspective view of an exemplary machine vision system. Fig. Figure 2 is a perspective view of an exemplary lighting module magnetically attached to part of the housing of the machine vision system. Fig. Figure 3 is a perspective exploded view of the lighting module and the housing of the Fig. 2, which are separate from each other. Fig. Figure 4 is a perspective exploded view of another exemplary lighting module magnetically connected to part of a housing of another machine vision system. Fig. Figure 5 is a perspective view of a machine vision system that includes an additional lens device magnetically connected to a lens of the machine vision system. Fig. Figure 6 is a perspective exploded view of the lens of the Fig. 5, which is in the machine vision system of the Fig. 5 is installed. Fig. Figure 7 is a perspective view of the lens of the Fig. 5, which are in the machine vision system of Fig. 5 has been installed. Fig. Figures 8A and 8B are sequential cross-sectional views of the additional lens device of the Fig. 5, which are connected to the lens of the Fig. 7 is connected. Detailed description

[0042] In some aspects, some components of a machine vision system, such as optical accessories (e.g., illumination devices, camera focusing systems (e.g., autofocus lens systems) (e.g., liquid lens systems)), camera protective devices (e.g., protective lens cap devices), optical filters, and various other types of optical accessories), can be connected to and disconnected from a camera device of the machine vision system using magnetic connecting elements.

[0043] With reference to Fig. 1. In some embodiments, a machine vision system 100 may include a housing 102, an image sensor 104 (shown in dashed lines) within the housing 102, and a lens system (e.g., an adjustable lens device) 106 arranged along an outer surface of the housing 102. The image sensor 104 defines an optical axis (e.g., a camera axis) 108, which is generally perpendicular to the image sensor 104. During use, the image sensor 104 is capable of recording (e.g., electronically decoding) images of objects positioned along and near the camera axis 108.

[0044] The lens system 106 is connected to the housing 102 (e.g., connected by fasteners, directly connected via a threaded connection, or otherwise secured to the housing 102) and is essentially aligned with the camera axis 108. One or more components of the machine vision system 100, such as the image sensor 104, are connected (e.g., electrically connected via a cable 110) to a control unit (e.g., an internal control unit) 112, which receives data from the image sensor 104 and decodes the data for processing. The machine vision system 100 can be connected to a user interface 111 (e.g., electrically connected via a wired connection 109) for use or processing.While the machine vision system 100 shown is typically intended for fixed reading applications, handheld camera systems or other scanning devices may include essentially similar components and may likewise be used with the systems and methods described herein.

[0045] The machine vision system 100 can include one or more optical accessories or devices, such as illumination devices (e.g., camera lens illumination modules), to illuminate an area (e.g., an object inspection field) in front of the lens system 106 for sufficient viewing and imaging capabilities. In particular, the camera lens illumination module can illuminate a target area along the camera axis 108 so that images of objects in the inspection field can be recorded for processing. The attachment and use of other types of optical accessories are described in more detail below.

[0046] For example, with reference to Fig. 2. In some embodiments, an optical accessory (e.g., a camera illumination module) 200 can be coupled to a portion of a camera housing 202 of a camera system in which a camera lens 204, defining the camera axis 108, is arranged. The illumination module 200 includes a generally flat structural base (e.g., an illumination plate) 206, which has a first, forward-facing surface along which one or more illumination elements 208 are arranged. The illumination elements 208 can include any of various types of light-emitting devices, such as light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), liquid crystalline displays (LCDs), or other suitable light-emitting devices.While the lighting module has been described as having multiple lighting elements, in some embodiments the lighting module includes only one lighting element. In some embodiments, the generally flat structural base does not include any lighting elements.

[0047] In some embodiments, the illumination plate 206 has the form of a printed circuit board (e.g., a printed circuit board), and the illumination elements 208 have the form of surface-mounted light-emitting elements (e.g., surface-mounted LEDs) arranged along the printed circuit board. As shown, in some embodiments, the illumination plate 206 has the form of a substantially round, disc-shaped circuit board with a hole formed in a central area. The hole is sized and shaped to allow the camera lens 204 to view an inspection field through the hole in the illumination plate 206. In some embodiments, the hole has a diameter approximately 1 mm to 5 mm larger than the diameter of the lens 204. For example, if the lens 204 has the shape of an M12-sized lens, the hole may have a diameter of approximately 15 mm to 18 mm.In another example, if the lens 204 has the shape of a C-mounted lens, the hole can have a diameter of approximately 35 mm to approximately 40 mm.

[0048] With reference to Fig. 3 includes the lighting module 200 at least one (e.g. three in the in Fig. (See example 3) Mounting element 210 extending from a second, downward-facing surface of the illumination plate 206, allowing the illumination module 200 to be connected to the camera housing 202. The mounting elements 210 extend from the illumination plate 206 at non-zero angles (e.g., substantially right angles) relative to the second, downward-facing surface of the illumination plate 206. As shown, the mounting elements 210 are typically distributed around the illumination plate 206 at substantially equal intervals (e.g., substantially equal angular intervals relative to a central axis). However, in some embodiments, the mounting elements may be arranged around the illumination plate at different distances from one another.The mounting elements 210 are typically dimensioned to have a length sufficient so that, when installed, the lighting plate 206 is positioned at a distance in front of the camera lens 204 (i.e., farther away from the housing 202 than from the camera lens 204). Such spacing can help to reduce or limit shadows in the inspection field that could potentially be formed by the camera lens 204 if the lighting elements 208 were positioned behind the camera lens 204.

[0049] As in Fig. As shown in Figure 3, the mounting elements 210 are, in some embodiments, essentially cylindrical, elongated, beam-like elements that generally have a round cross-sectional shape. For the sake of simplicity, the other parts of the housing and the camera system are not shown. Fig. Figure 3 shows the following. However, the mounting elements can have other cross-sectional shapes. For example, the mounting elements can have a cross-sectional shape including other round shapes (e.g., elongated, elliptical, or circular shapes), polygonal shapes (e.g., rectangular, square, pentagonal, hexagonal, or other polygonal shapes), or a shape including a combination of one or more curved and / or straight sides.

[0050] The mounting elements 210 are distributed around the lighting plate 206 so that they can be received within several mounting recesses 212 formed along the camera housing 202. The mounting recesses 212 are typically dimensioned and shaped similarly to, but somewhat larger than, the cross-sectional size and shape of the mounting elements 210. For example, as in Fig. 3 shown, when substantially round mounting elements 210 are used, the mounting recesses 212 are formed as substantially round recesses to receive the mounting elements 210.

[0051] The assembly elements 210 can be formed by any suitable manufacturing technique (e.g. injection molding or machining) and can be made from any suitable material, such as metal, plastic, composite material or any suitable combination of these materials.

[0052] The mounting elements 210 can be connected to the lighting plate 206 using any of several suitable joining techniques or methods, including fastening using fasteners (e.g., screws or rivets), bonding using adhesive (e.g., glue or epoxy), mechanical bonding (e.g., welded, soldered, or attached via a press fitting), or any other suitable method. In some embodiments, the mounting elements 210 and the lighting plate 208 are formed as a single component.

[0053] At least one of the mounting elements 210 includes a retaining element, such as a magnetic element (e.g., a magnet or a ferromagnetic element) 214, which is arranged at a distal end (e.g., the end facing away from the lighting plate 206) of the mounting element 210. The magnetic element 214 can be attached to the mounting element 210 by any of several suitable methods, including a bolted connection, a bonded connection, or a press-fit connection. The magnetic element 214 is dimensioned and configured to magnetically couple an adjacent magnetic receiving element (e.g., a ferromagnetic element or a magnet) 216 that is arranged on or along the housing 202. For example, the magnetic receiving element 216 can be a ferromagnetic element that is coupled to the housing 202 (e.g., bolted, bonded, or pressed).In some embodiments, the magnetic receiving element 216 is formed as an integral component of the housing 202.

[0054] The magnetic element 214 is configured to produce a magnetic field that generates a magnetic holding force sufficient to couple the illumination module 200 to the housing 202. For example, in some embodiments, the magnetic holding force generated between the magnetic element 214 and the magnetic receiving element 216 can range from about 0.5 lbf to about 5 lbf.

[0055] The magnetic connection between the optical accessory and the machine vision system can take the form of several configurations. For example, as shown, in some embodiments the magnetic element located on the mounting element can include a magnet, and the magnetic receiving element on the housing can include a ferromagnetic element configured to generate a magnetic force with the magnet. Alternatively, in some embodiments the magnetic element located on the mounting element can include a ferromagnetic element, and the magnetic receiving element on the housing can include a magnet configured to generate a magnetic force with the ferromagnetic element.Alternatively, in some embodiments, the magnetic element mounted on the mounting element may contain a magnet, and the magnetic receiving element on the housing may also contain a magnet. The two magnets may be arranged to generate a magnetic force between them. For example, the magnets may be arranged to have opposite magnetic polarities (e.g., a magnetic north pole of one magnet facing a magnetic south pole of the other magnet).

[0056] The magnetic element 214 typically takes the form of a permanent magnet, such as a rare-earth magnet. In the example shown, the magnetic element is a neodymium magnet. In some embodiments, the magnetic element includes a composite permanent magnet (e.g., a ceramic magnet, a ferrite magnet, an Alnico magnet, or a flexible magnet). Alternatively or additionally, other types of magnets, such as electromagnets, may be used.

[0057] In some embodiments, the lighting module 200 includes an electrical mounting element to provide electrical power to the optical accessories, e.g., to power and control the lighting elements 208. For example, with reference to Fig. 3. In some embodiments, an electrical mounting element 218 takes the form of an electrical connector located at a distal end of the mounting elements 210. The electrical mounting element 218 is connected to the lighting elements 208, for example, via a wired connection (e.g., a cable harness) located within the mounting element 210 to the conductive areas along the lighting plate 206, along which the lighting elements 208 are arranged. By using the electrical mounting element 218 and the conductive areas of the lighting plate 206, electricity can be distributed and supplied from the camera system to the lighting elements 208. For example, electrical control signals or detection signals, such as those from a sensor (e.g.,(a temperature sensor) arranged on the illumination plate 206, is transmitted between the control unit 112 and the illumination plate 206 via the electrical mounting element 218. Specifically, the electrical mounting element 218 is dimensioned and configured to be electrically connected to a receiving electrical connector 220, which is arranged along the housing 202 and is electrically connected to one or more of the imaging sensors 104 or the control unit 112. Consequently, once connected, the illumination module 200 can be operated by the camera system to properly operate the illumination elements 208 to produce a desired illumination field based on the environment in which the camera system is used.

[0058] In some embodiments, the electrical fastener 218 and the receiving electrical connector 220 take the form of an electrical connector having one or more resilient, flexible electrical connection pins 222. In some embodiments, the flexible electrical connection pins include one or more pins that are biased (e.g., spring-loaded) against an intended mating electrical contact surface. Using the flexible electrical connection pins 222, an electrical connection can be established between the electrical fastener 218 and the receiving electrical connector 229 without integrally coupling the two connectors (i.e., without having to insert a male connector and retain it within a female connector).For example, when the electrical mounting element 218 is placed against or along the receiving electrical connector 220, which has flexible electrical connection pins 222, the flexible electrical connection pins 222 make contact and are bent by the corresponding electrical contacts 224 arranged along the electrical mounting element 218 to establish the desired electrical connection. Typically, when the illumination module 200 is installed on the camera housing 202, the magnetic elements 214 provide a magnetic retention force that temporarily secures the electrical mounting element 218 against the receiving electrical connector 220 to bend the flexible electrical connection pins 222 and establish the electrical connection.

[0059] With reference to Fig. 3. The electrical mounting element 218 and the magnetic element 214 can be arranged at a distal end of the same mounting element 210. By using this type of configuration, in which the magnetic element 214 surrounds the electrical mounting element 218 when the illumination module 200 is installed on the camera housing 202, the magnetic element 214 can help to align the electrical mounting element 218 and the receiving electrical connector 220, and thereby also help to align the flexible electrical connection pins 222 with the corresponding electrical contacts 224.

[0060] As previously discussed, the illumination module 200 can typically be attached quickly and easily to the camera housing 202 using the magnetic element 214. To install the illumination module 200, it can be aligned on the housing 202 (e.g., centrally along the camera axis 108) so that the electrical mounting element 214 is aligned with the receiving electrical connector 220, and so that each of the mounting elements 210 is aligned with a corresponding mounting recess 212. Once aligned, the illumination module 200 can simply be moved towards the housing 202 and placed on it. When placed on the housing 202, the magnetic element 214 generates a magnetic holding force that retains the illumination module 200 on the housing 202.As discussed previously, this retaining force also helps to establish an electrical connection by bending the electrical connection pins 222 with the corresponding electrical contacts 224. Once connected, the lighting elements 208 can be operated (e.g., by the camera device or the control unit) to illuminate a target area along the camera axis 108, so that images of objects positioned in the inspection field can be recorded for processing by the control unit.

[0061] As discussed below, in some embodiments the optical accessory may include an electrical connection (e.g., a wiring harness) with wires that are connected (e.g., soldered) to the illumination panel. The wiring harness may have a connector configured to engage with a corresponding connector of the machine vision system. Optical accessory application method

[0062] By using the optical accessories (e.g., the illumination module 200), a machine vision system can be set up more quickly and easily than other illumination modules and adjusted during use, if necessary. For example, the machine vision system can be mounted so that the camera axis 108 is generally directed toward a desired inspection area, such as a section of a production line. With the camera system in position, the lens 204 can be adjusted (e.g., manually) to properly focus the camera system. Once the lens 204 is correctly adjusted based on the desired inspection area, the illumination module 200 can be placed on the camera housing 202 and held in place by the magnetic retention force generated by the magnetic element 214.As previously discussed, when the lighting module 200 is installed on the camera housing 202, the magnetic holding force also holds the electrical mounting element 218 against the receiving electrical connector 220, allowing the flexible electrical connection pins 222 to bend and establish the electrical connection. Once installed, the lighting module 200 can be powered and operated, so that the lighting elements 208 emit light to illuminate the desired inspection area.

[0063] If it is necessary to change or adjust the lens 204 during use (e.g., as a result of a change in the inspection field or a change in the objects being imaged), the illumination module 200 can be easily removed (e.g., by manually pulling the illumination module 200 away from the housing 202), the lens 204 can be changed or adjusted, and the illumination module 200 can be reinstalled (e.g., by manually placing it back onto the housing 202). This ability to quickly modify the camera system without the use of additional tools or complex techniques can help reduce downtime in the environment where the camera systems are used and, consequently, can help reduce lost operating time that would otherwise occur during such adjustments.In some cases, it may be advantageous to be able to remove, adjust, and / or replace optical accessories with only one hand if the machine vision device is in hard-to-reach locations, e.g., if the machine vision system is located near automated processing areas (e.g., six feet above a conveyor belt).

[0064] While certain embodiments have been described, other embodiments are possible. In some embodiments, the optical accessory includes an alignment feature that helps to restrict the installed orientation of the optical accessory relative to the camera body. For example, in some embodiments, the alignment feature includes the magnetic element, which is arranged such that its magnetic polarity restricts the orientation in which the optical accessory can be attached to the body. In some embodiments, more than one mounting element (e.g., two mounting elements) includes a magnetic element, and the magnetic elements are arranged such that, due to their magnetic polarity, the optical accessory can only be correctly attached to the body in one orientation.

[0065] For example, in some embodiments, the positions of the mounting elements can help to limit the orientation in which the optical accessories can be installed. For example, with regard to Fig. 4, in some embodiments, includes an optical accessory (e.g., a lighting module) 300 and the mounting elements 210A, 210B, which are arranged separately from one another or separated from a mounting element 210 by different distances. As shown, a first mounting element 210A is separated from the mounting element 210, which includes a magnetic element 214 and an electrical fastening element 218, by a first angle θ1 relative to a central axis of the lighting module 300. In contrast, the second mounting element 210A is separated from the mounting element 210 by a second angle θ2 relative to the central axis of the lighting module 300.To receive the lighting module 300, a housing 302 includes a first mounting recess 212A and a second mounting recess 212B, arranged at the first angle θ1 and the second angle θ2 respectively, relative to the receiving electrical connector 220. In this configuration, as a result of the positions of the mounting elements 210A, 210B and the mounting recesses 212A, 212B, the lighting module 300 can only be properly installed in one orientation relative to the housing 302. If not properly oriented, if one of the mounting elements is aligned with an unintended mounting recess, then an adjacent mounting element would inadvertently come into contact with the housing (i.e., and not with an intended mounting recess).

[0066] Alternatively or additionally, in some embodiments, each of the two mounting elements includes a magnetic element arranged along its distal tip, wherein the two magnetic elements have outwardly facing polarities that are opposite to each other (e.g., one magnetic element has its north pole facing outwards and the other magnetic element has its south pole facing outwards). To receive the two magnetic elements of the mounting elements, the camera system (e.g., the housing) can include two matching magnetic receiving elements, which contain magnetic elements arranged in the same way so that their opposite polarities are facing outwards, in order to magnetically attract the magnetic elements arranged on the mounting elements when the optical accessory is positioned in a desired, matching orientation.For example, using this configuration, if the optical accessory is placed against the housing in an incorrect orientation, the polarities of the magnetic elements will typically cause the misaligned magnetic elements to repel each other and prevent the optical accessory from being installed incorrectly.

[0067] Alternatively or additionally, in some embodiments, the alignment feature includes the fact that the mounting elements and the mounting recesses have different cross-sectional shapes or sizes. For example, in some embodiments, the optical accessory includes at least two mounting elements that have different cross-sectional dimensions (e.g., average diameters), such that the mounting elements only fit into the mounting recesses in one orientation. This means that in an incorrect orientation relative to the housing, at least one of the mounting elements has a diameter that is too large to fit into a mounting recess that has a smaller diameter to accommodate the mounting element with the smaller diameter.

[0068] Additionally or alternatively, in some embodiments, the optical accessory includes at least two mounting elements having different cross-sectional shapes. For example, an optical accessory may include one mounting element having a generally round cross-sectional shape, dimensioned to be received in a generally round mounting recess, and one mounting element having a generally square cross-sectional shape, dimensioned to be received in a generally square mounting recess. Consequently, as a result of the differently shaped mounting elements and mounting recesses, the optical accessory can only be properly attached to the housing in one orientation.While the differently shaped mounting elements have been described as round or square shaped mounting elements, any two matching differently shaped mounting elements can be used to limit an installed orientation.

[0069] Additionally or alternatively, in some embodiments, the optical accessory includes a first mounting element, which contains the magnetic element and the electrical connector, and a second mounting element that is received in a mounting recess. Consequently, based on the structural differences between the receiving electrical connector and the mounting recess located along the housing, the optical accessory can only be installed correctly in one orientation.

[0070] While the optical accessories have been described as having extended mounting elements that act as spacers to position the optical accessories at a distance from the housing, other configurations are possible. For example, in some embodiments, the mounting elements take the form of beam-like spacers that are mounted to or otherwise connected with and extend from the camera housing instead of the structural base. In such embodiments, the structural base can be attached to the mounting elements (i.e.,, in contrast to the structural base and mounting elements being attached to the housing), In some embodiments both the structural base and the housing may include one or more mounting element portions, respectively extending from the structural base and the housing to appropriately position the structural base relative to the camera housing and the camera lens at a distance].

[0071] While the optical accessory has been described and illustrated as having three mounting elements, the optical accessory may include more or fewer mounting elements. For example, in some embodiments, the optical accessory includes one, two, four, five, six, seven, eight, or more mounting elements spaced apart around the illumination plate. In some embodiments, the mounting element takes the form of an arc-shaped (e.g., ring-like) mounting element arranged along a surface of the optical accessory. In some embodiments, a ring-like mounting element may take the form of a single ring-like magnetic element.

[0072] While the mounting recesses have been described as essentially round to receive essentially round mounting elements, other configurations are possible. For example, if the mounting elements in some embodiments have a different cross-sectional shape, the mounting recesses typically have a similar cross-sectional shape, such as other curved shapes (e.g., elongated, elliptical, or oval shapes), polygonal shapes (e.g., rectangular, square, pentagonal, hexagonal, or other polygonal shapes), or a shape including a combination of one or more curved and / or straight sides. For example, if, in some embodiments, mounting elements having a generally square cross-sectional shape are used, the mounting recesses may also have a generally square cross-sectional shape to accommodate the mounting elements.

[0073] While the structural base has been described as an essentially round lighting plate (e.g., a printed circuit board) with a centrally formed hole, lighting plates of other sizes and / or shapes are possible. For example, in some embodiments, the structural base has a different outer shape, such as other curved shapes (e.g., elongated, ellipsoidal, or oval shapes), polygonal shapes (e.g., rectangular, square, pentagonal, hexagonal, or other polygonal shapes), or a shape including a combination of one or more curved and / or straight sides.

[0074] In some embodiments, the structural base does not include a hole for the camera lens to view the inspection field. For example, the structural base may include a transparent or semi-transparent area (e.g., a transparent area along the camera axis) through which the camera lens can view the inspection field.

[0075] In some embodiments, the structural base is formed from several segments arranged around the camera lens. For example, the structural base can be formed from one or more segments arranged around the camera lens (e.g., on opposite sides of the camera lens).

[0076] While the structural basis has essentially been described as a printed circuit board, other configurations are possible. In some embodiments, the structural basis includes an enclosure-type device, such as a plastic body, which incorporates electrical connections to supply power to the lighting elements. Camera lens mounting devices

[0077] While the systems and methods previously described that use magnetic elements to connect one or more optical accessories to a machine vision system were generally described and illustrated as being implemented on the camera system's illumination modules, other configurations are possible. For example, other optical accessories, such as additional lens devices (e.g., a liquid lens device that can be adjusted to change the camera system's focal length), can be attached to a camera system using magnetic retention elements.

[0078] With reference to Fig. 5 and Fig. 6 includes, in some embodiments, a machine vision system 400, a housing 402, an image sensor 104 arranged within the housing 302, and an optical accessory (e.g., an additional lens device 404) arranged on a lens 406 of the image sensor 104 along a camera axis 108 that is substantially perpendicular to the image sensor 104. The lens 406 is secured within a recess 408 of the housing 402 along an outer surface of the housing 402. The lens 406 can be secured using any of various fastening techniques, including being attached via a threaded connection, being joined using adhesives, or being otherwise connected (e.g., welded or completely cast within the housing 402). With reference to Fig. Figure 6, which depicts the machine vision system 400 without the additional lens device 404 and with the lens 406 removed from the housing 402, shows the lens 406 incorporating a retaining element (e.g., a ferromagnetic retaining ring) 407 configured to engage with a magnetic element (e.g., a permanent magnet) 412 of the additional lens device 404. For example, as discussed below, during installation, the additional lens device 404 can be placed on the lens 406 so that the magnetic element 412 can provide a magnetic retaining force to secure the additional lens device 404 to the retaining ring 407 of the lens 406, thereby securing the additional lens device 404 to the housing 402.While the lens 406 has been described as including a retaining ring to interlock with the magnetic element, the lens may include retaining elements of other shapes and sizes that are arranged to be magnetically coupled with the magnetic element 412.

[0079] The additional lens device 404 includes a lens module 410, the magnetic element 412 (also shown in the Fig. 8A and Fig. 8B) and a wiring harness 414 that electrically connects the lens module 410 to the machine vision camera system 400. For example, as in Fig. As shown in Figure 7, a connector 416 of the cable harness 414 can be inserted and connected to the plug socket 418, which is arranged along a front surface of the housing 402. The plug socket 418 can be electrically connected to the internal electrical components of the machine vision camera system 400 or to a control unit that operates the machine vision camera system 400. The lens module 410 can include any of the devices or components for adjusting or changing different lenses. In the example shown and described here, the lens module 410 includes a camera focusing system, such as an autofocus system (e.g., a liquid lens system), which can be adjusted (e.g., remotely electronically adjusted) to change the focal length of the machine vision camera system 400.

[0080] In some embodiments, the lens module 410 may additionally or alternatively include other types of optical accessories or devices, such as illumination devices, camera focusing systems (e.g. autofocus lens systems (e.g. liquid lens systems)), camera protective devices (e.g. protective lens cap devices) and optical filters.

[0081] The magnetic element 412 is sized and configured to magnetically couple with the retaining ring 407, which is arranged along the lens 406. For example, the magnetic element 412 is configured to produce a magnetic field that generates a magnetic retaining force sufficient to couple the additional lens device 404 to the housing 402. For example, in some embodiments, the magnetic retaining force generated between the magnetic element 412 and the retaining ring 407 may be from about 0.5 lbf to about 5 lbf.

[0082] The magnetic element 412 typically takes the form of a general permanent magnet, such as a composite permanent magnet (e.g., a ceramic magnet, a ferrite magnet, an Alnico magnet, or a flexible magnet). In the example shown, the magnetic element is a neodymium-type magnetic element. Alternatively or additionally, other types of magnets can be used, such as other permanent magnets (e.g., rare-earth magnets or single-molecule magnets) or electromagnets.

[0083] To install the lens 406 and the additional lens assembly 404 on the housing 402, the lens 406 is first attached to the housing (e.g., within the recess 408 of the housing 402). In the example shown, the lens 406 is secured with a thread within the recess 408. Once secured in the recess 408, a cylindrical portion 409 of the lens 406, which is essentially aligned along the camera axis 108, extends outwards from the housing 402 to support and align the lens module 410. Then, with reference to Fig. 8A and Fig. 8B, the additional lens device 410 is aligned with the lens 406 so that a lens receiving aperture 411 of the additional lens device 404 is positioned in front of the cylindrical portion 409 of the lens 406. Once aligned, the additional lens device 404 can be placed on the lens 406 so that the cylindrical portion 409 is inserted into the lens receiving aperture 411 and received, and the magnetic element 412 is positioned near the retaining ring 407 so that a magnetic retaining force is generated between the magnetic element 412 and the retaining ring 407. As in Fig.As shown in Figure 8B, the magnetic element 412 and the retaining ring 407 do not necessarily need to be in contact with each other when installed, as long as they are in sufficiently close proximity to generate an adequate magnetic retention force. Separating the magnetic element 412 and the retaining ring 407 can help reduce the likelihood of improper fitting of the additional lens device 410 onto the lens 406, for example, as a result of variations in the length of the lens 406 or the additional lens device 410. For example, in some cases, the distance between the magnetic element 412 and the retaining ring 407 can be used to compensate for tolerance variations in the length of the lens 406, which may be up to 0.5 mm.

[0084] Once magnetically secured axially to the lens 406 along the camera axis 108, the additional lens device 404 can typically be rotated about the camera axis 108. For example, in some embodiments, the additional lens device 404 is rotated about the camera axis 108 to align the lens module 410 with a desired inspection field to be viewed and imaged by the machine vision camera system 400. Additionally, the additional lens device 404 can be rotated to align the cable harness 414 and the connector 416 so that the connector 416 can be inserted into the plug socket 418 to provide power and control signals to the additional lens device 404 or to send signals (e.g., measurement signals, such as liquid lens membrane stress signals) to the machine vision system 400.

[0085] While the electrical connection between the optical accessory and the camera device has been described and illustrated as being achieved via electrical connectors having flexible electrical contact pins, the electrical connection can be established using any of the other suitable electrical connectors. For example, in some embodiments, the optical accessory may incorporate any of the other different types of electrical connectors (e.g., a plug and socket type connector, a flat pin type connector, a jack plug (e.g., a registered jack plug), a USB type connector, a power connector, a terminal block type connector, or other suitable types of connectors). For example, the electrical fastener may be of a male or female style, and the housing may incorporate the opposite, corresponding electrical connector.

[0086] In some embodiments, the electrical mounting element includes an external electrical connector that is wired to the structural base (i.e., not located within or on the mounting elements). By using such a separate wired connector, the structural base can be attached to the camera housing (e.g., using a magnetic retention force), and the wired connector can then be connected to an adjacent connector within the housing (e.g., inserted into a coherent connector located within the camera housing). In some embodiments, the optical accessory includes a magnetic element on one of the mounting elements to secure the optical accessory to the housing, and likewise a connector having bendable pins and an additional magnetic element to join the bendable pins.

[0087] While the optical accessory (e.g., the additional lens device) has been described as being electrically connected to the machine vision camera system to receive electrical power and controls, other configurations are possible. For example, in some embodiments, the optical accessory is connected to an electrical source outside the machine vision camera system (e.g., electrically connected using the wiring harness). In some embodiments, the optical accessory is manually adjustable (e.g., by hand) and is not electrically connected to the machine vision camera system.

Claims

[1] Optical accessory (200) that is to be temporarily coupled to a surface of a separate machine vision device (100) along a camera axis (108) of an imaging device of the machine vision device (100), the optical accessory (200) comprising: a structural base (206) having a first surface and a central viewing area through which the machine vision device (100) can view a field of view; at least one mounting element (210) extending from a second surface of the structural base (206) to engage with a surface of the separate machine vision device (100), wherein the at least one mounting element (210) is dimensioned to have a length sufficient so that, when installed, the structural base (206) is positioned at a distance in front of a lens (204, 406) of the separate machine vision device (100); and a magnetic element (214, 412) arranged at a distal end of the at least one mounting element (210), wherein the magnetic element (214, 412) generates a magnetic retention force that secures the optical accessory (200) to a surface of the machine vision device (100). [2] Optical accessory (200) according to claim 1, wherein the surface of the machine vision device (100) comprises a surface of a ferromagnetic retention element arranged around the lens (204, 406). [3] Optical accessory (200) according to claim 1, wherein the optical accessory (200) comprises an adjustable lens that modifies an optical property of the machine vision device (100). [4] Optical accessory (200) according to claim 1, further comprising an electrical fastening element, wherein the electrical fastening element electrically couples the optical accessory (200) to at least one of a power source or control device of the machine vision device (100). [5] Optical accessory (200) according to claim 4, wherein the electrical fastening element comprises an electrical connector (220, 229) in a wired connection with the optical accessory, wherein the electrical connector (220, 229) connects to the at least one of a power source or control device of the machine vision device (100). [6] Optical accessory (200) according to claim 4, wherein, when connected to a power source, the electrical fastening element provides electrical power to adjust a focal length of the machine vision device (100). [7] A camera system comprising: a camera casing; a lens (204, 406) arranged in or along a front surface of the camera enclosure along an optical axis of the camera system; an optical accessory (200) which is removablely attached around the lens (204, 406) along the front surface of the camera enclosure in a separable and interchangeable manner, wherein the optical accessory (200) comprises a structural base (206) having a first surface and a central viewing area through which the camera system can view a field of view, and wherein the optical accessory (200) comprises at least one mounting element (210) extending from a second surface of the structural base (206) to engage with a surface of the camera system, wherein the at least one mounting element (210) is dimensioned to have a length large enough so that, when installed, the structural base (206) is positioned at a distance in front of the lens (204, 406); wherein the optical accessory (200) is attached using a magnetic retention force provided by at least one magnetic element (214, 412), wherein the at least one magnetic element (214, 412) is arranged at a distal end of the at least one mounting element (210) to secure the optical accessory (200) to a surface of the camera system. [8] Camera system according to claim 7, wherein the at least one magnetic element (214, 412) is a component of the optical accessories. [9] Camera system according to claim 7, wherein the optical accessory (200) comprises an alignment device which limits an installed alignment of the optical accessory relative to the camera enclosure. [10] Camera system according to claim 7, wherein the magnetic retention force is generated between a first magnetic element (214, 412) of the at least one magnetic element (214, 412) arranged on the optical accessory and a ferromagnetic retention element arranged on the lens (204, 406), and in a fixed configuration the first magnetic element (214, 412) is arranged separately from the ferromagnetic retention element.

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