Lighting device for providing light for measuring the light properties of a material or light source, and modular system for producing several variants of a lighting device.

Abstract

The invention relates to a lighting device (10) for providing light for measuring the light properties of a material (19), comprising a housing which at least partially defines at least one receiving space (29), a holding device (34) for attaching a light source in the receiving space (29), a cover (14) detachably held on the housing and having a light emission opening (15) through which light emitted from the lighting device (10) can be directed onto the material (19), a light guide arrangement (26) arranged between the holding device (34) and the cover (14) through which light emitted from the light source can be directed to the light emission opening (15), and a control device (23) for controlling the power supply to the light source. The invention also relates to a modular system for producing several variants of such a lighting device (10).

Description

[0001] The invention relates to a lighting device for providing light for measuring the light properties of a material or a light source, comprising a housing that at least partially defines a receiving space, a holding device for a light source, a light guiding arrangement for directing light emitted by the light source, a control device for controlling the light source, and a cover for the housing. The invention also relates to a modular system for manufacturing several variants of a lighting device.

[0002] DE 199 17 306 A1 discloses an optical analysis device with a light-tight housing with a measuring chamber for receiving a sample, a measuring light receiver arranged in the housing for measuring light emanating from a sample, a reference light source with a light transmitter for calibrating the measuring light receiver, and a control and evaluation device connected to the measuring light receiver and the reference light source.

[0003] US Patent 5,260,584 A discloses a portable, handheld reflectometer that includes at least one blue light-emitting diode for measuring the optical brightness of an opaque material, such as a stack of paper.

[0004] DE 10 2008 026 803 A1 discloses an analytical apparatus system in combination with a digital camera and a method for determining substances in liquids using this system.

[0005] CN 114279563 A shows a portable radiation standard source and a radiation calibration method for an imaging spectrometer.

[0006] DE 823 013 B shows a device for directed red or infrared radiation, which is characterized by a reflector surface inclined in the area of ​​the emitter to a normal of the emitter surface and transitioning into a reflecting cylindrical surface after the opening.

[0007] The object of the invention is to provide a lighting device for supplying light for measuring the light properties of a material, which is particularly mobile or handy and with which light can be provided reproducibly or repeatably for light measurements. Furthermore, the object of the invention is to provide a modular system for manufacturing several variants of such a lighting device.

[0008] The problem is solved by the subject matter of the independent claims. Advantageous further developments or embodiments of the invention are described by the dependent claims, the following description, and the figures.

[0009] A first aspect of the invention relates to a lighting device for providing light for measuring the light properties of a material, comprising a housing, in particular opaque or light-tight, which at least partially delimits at least one receiving space, a holding device for attaching a light source in the receiving space, a cover which is held on the housing in a non-destructively reversible manner and which has a light emission opening through which light emitted from the light source can be emitted from the lighting device to act on the material, a light guiding arrangement arranged between the holding device and the cover through which light emitted from the light source can be guided to the light emission opening, and a control device for controlling a power supply, in particular an electrical supply, to the light source.In other words, the housing, which at least partially defines the recording space, can be closed with the lid. The lid can be detached from the housing non-destructively and reversibly by means of a magnetic device. For the magnetic device, the housing can, for example, have a first magnet and the lid a second magnet corresponding to the first. When the housing or recording space is closed with the lid, the two magnets can be positioned opposite each other and / or can make contact when the lid is held in place. The lid is attached to the housing by a lid holder, allowing for non-destructive and reversible detachment. For this purpose, the lid has a first magnet and the lid holder a second magnet. When the lid is mounted on the housing, the two magnets attract each other and make contact, thus holding the lid securely to the housing.The mounting device, on which the light source can be attached, can be arranged, particularly within the receiving chamber. The light guide is intended to direct light emitted by the light source to the cover, especially when the receiving chamber is closed by the cover, and in particular to the light emission opening of the cover. The light emission opening can be designed as a recess or hole in the cover, particularly a circular one. Light emitted or radiated by the light source can be emitted into the surroundings through the light emission opening. Preferably, the material whose light properties are to be examined when irradiated with light from the lighting device is arranged on an outer side or on the side facing the surroundings of the cover that closes the receiving chamber.In particular, the material covers the light emission aperture so that it is illuminated or at least partially traversed by the light guided to the emission aperture via the light guide arrangement and passing through it, for example, if the material is at least partially transparent. A measuring device, in particular a light measuring device, can be arranged or may be arranged downstream of the material, along the luminous flux originating from the light source. In other words, the lighting device is designed to be arranged at least indirectly on a light measuring device, with the material to be examined being arranged between the lighting device and the light measuring device.The control unit can be electrically connected to the mounting device, for example, by means of live cables, through which the light source, which can be attached to or is attached to it, can be supplied with current, thus causing it to illuminate. The control unit can be used, for example, to adjust the electrical power supplied to the light source. Additionally or alternatively, the control unit can maintain a constant voltage and / or current when the light source is supplied with electrical current, while varying the other parameter, i.e., the current or voltage.The lighting device offers the advantage that reproducible or repeatable lighting conditions can be created under the same conditions, meaning that the material can always be exposed to the same light in order to measure the material's light properties.

[0010] According to the invention, the holding device is designed to accommodate a sample holder for fixing the light source, and the sample holder can be removed from the holding device in a non-destructive and reversible manner. In other words, the light source is encompassed by or attached to the sample holder and can be attached to or replaced on the holding device. For this purpose, the holding device has two mounting rails, each with a stop, into which the sample holder can be inserted and moved along the mounting rails up to the two stops. The sample holder can then be fixed in a translational position by means of a magnetically attachable holder on the holding device.The sample holder can be fixed vertically (towards the lid) and laterally or transversely by the two mounting rails, in particular by guides in the two mounting rails, especially in a form-fitting manner. For this purpose, the mounting device has one or more magnets by means of which the sample holder can be fixed to the mounting device, thus ensuring that the sample holder is immovably fixed in all three spatial directions. The mounting device can have an electrical connection, for example, two electrical contacts, with which two contacts arranged on the sample holder can be electrically connected or made to connect when the sample holder is picked up in the mounting device or inserted until it reaches its stop. Electrically conductive lines, connected or connectable to the light source, can be arranged on the sample holder itself to supply the light source with electrical current from the mounting device.This offers the advantage that a sample holder, in particular a light source fixed to the sample holder, is interchangeable, and thus light from different light sources or light sources can be provided by the lighting device to illuminate the material to be examined.

[0011] The first aspect of the invention also includes embodiments or further developments that result in additional advantages.

[0012] A further development of the lighting device provides that a power measuring device, comprising a power sensor for measuring the electrical power and / or current and / or voltage that can be supplied to the light source or, in particular, is supplied or is supplied when the lighting device is in operation, is included in the lighting device. In other words, the power measuring device should be able to measure the current, voltage, and / or power supplied to the light source when the lighting device is in operation.Although the current, i.e., the power, amperage and / or voltage for operating the light source can be specified by the control unit, deviations from this may occur. For example, the actual electrical power (and / or amperage and / or voltage) reaching the light source may differ from the electrical power (and / or amperage and / or voltage) set by the control unit, for example due to electrical cable resistance through which the supply current from a power source or the control unit is supplied to the light source or the holding device.This offers the advantage that the actual electrical power, voltage, and / or current with which the light source is operated can be measured and adjusted if there is an intolerable deviation from the current values ​​set or specified by the control unit. The power sensor can, for example, be integrated into the holding device.

[0013] A further development of the lighting device provides that the housing has a touch-sensitive display and operating device for operating the control unit and / or for outputting measured values ​​from the power measuring device. The display and operating device can, for example, be designed as a touch display and be arranged on an outer surface of the housing, i.e., on a side of the housing facing the environment, in particular on a side visible from the outside, for example on a side wall of the housing.The display and control unit allows the user to view and adjust the specified target current (electrical power, voltage, and / or current) set via the control unit, for example, using buttons on the display. Alternatively, it can output current measurements (electrical power, voltage, and / or current) detected or sensed by the power sensor of the power measuring device. This offers the advantage of particularly easy adjustment and / or output of the current values ​​used to power the light source.

[0014] A further development of the lighting device provides that the light guiding arrangement is designed as a baffle arrangement with at least two planes, each with a perforated aperture having a corresponding opening, and that the light exit aperture and the perforations are arranged collinearly. Thus, the light source, the two openings, and the light exit aperture are arranged along a straight line, i.e., collinearly. This offers the advantage that the light exiting the aperture can be directed. The two perforated apertures can be arranged vertically, one above the other, between the lighting device and the cover or the light exit aperture in two parallel planes. Each perforated aperture can be designed as a plate that is opaque except for its respective opening.To prevent light reflections, the apertures can be black. The aperture closest to the light source in the vertical direction can be called the first aperture, and the one furthest away from the light source in the vertical direction can be called the second aperture. Non-collinear light rays are blocked by the apertures and cannot reach or pass through the light exit aperture. A light ray passing obliquely through the first aperture, i.e., at an angle to the line between the light source, the apertures, and the light exit aperture, can strike the plate of the aperture with the second aperture and thus cannot pass through the second aperture to reach the light exit aperture.Light rays aligned collinearly or parallel to the intended beam direction (from the light source through both apertures and through the light exit aperture) can pass through the first aperture, the second aperture, and the light exit aperture. This offers the advantage that the material under investigation can be illuminated with directed light. For example, this allows for a better assessment of the refractive index of the material than with undirected or diffuse light.

[0015] A further development of the lighting device provides that the light guide assembly is designed as a cylindrical reflector whose central axis, which can be an axis of rotational symmetry, can be arranged collinearly with the light emission aperture. In particular, the cylindrical reflector can be positioned between the light source and the light emission aperture such that the light source, its central axis, and the light emission aperture are aligned in a line or on a straight line. Viewed from the outside, the cylindrical reflector has a cylindrical shape and is hollow inside to allow light to pass through. The inside of the reflector, i.e., the side facing the light, can be white or mirrored, for example, coated with metal, so that the inside is light-reflecting.This offers the advantage that a particularly large amount of the light emitted by the light source can be directed to or through the light exit aperture. Specifically, light rays entering the reflector at an angle, i.e., deviating from the reflector's central axis, are not filtered out as with a pinhole aperture, but are reflected from the inside of the reflector and thus directed to or through the light exit aperture. This can be particularly advantageous when the material under investigation is to be illuminated with a large amount of light, or at least with partially undirected or diffuse light.

[0016] A further development of the lighting device provides that the housing has an external mounting device. The housing can have a top surface to which the cover can be attached, or which either includes or supports the cover in its attached state; a bottom surface positioned opposite the top surface to the intended beam direction; and side walls formed in the four directions perpendicular to the intended beam direction, i.e., around the intended beam direction. The mounting device can be arranged on the inside of the bottom surface or bottom wall of the housing. On the outside of the housing, the mounting device can, for example, include one or more flanges by means of which the lighting device can be fixed.For example, one or more flanges can have one or more holes through which screws can be passed, allowing the lighting device to be attached to a measuring device, for instance. This offers the advantage that the lighting device cannot slip or move relative to the measuring device and / or the material being examined during a light measurement; in other words, it can be fixed in place. The desired beam direction or light guidance direction can run along a line from the light source to the light-emitting aperture.

[0017] A further development of the lighting device stipulates that the lighting device be designed as a portable lighting device. In other words, the lighting device should be portable, especially by one person, and therefore weigh less than 15 kilograms, preferably less than 5 kilograms, and have a volume of less than 0.03 m³. 3It has a shape (corresponding to a cube with 30 cm edges). This offers the advantage that the lighting device, for example in a laboratory for light analysis, is particularly easy to handle, meaning it can be positioned particularly well on a measuring device.

[0018] A further development of the lighting device stipulates that, for operation, the device must have a power plug that can be connected to a standard 230-volt household electrical system. In other words, the lighting device should be operable via a 230-volt power supply. Additionally or alternatively, the lighting device can be operated using, for example, an American standard electrical system that provides 110 volts. This offers the advantage of particularly easy operation.

[0019] A second aspect of the invention relates to a modular system for manufacturing several variants of a lighting device, particularly according to the first aspect of the invention. Advantages and advantageous developments of the first aspect of the invention are to be regarded as advantages and advantageous developments of the second aspect of the invention, and vice versa.

[0020] The modular system comprises at least the housing, the holding device, the control device, at least two covers with at least one light exit aperture, wherein the light exit apertures have different diameters, as light guiding arrangements at least two aperture arrangements each with a pair of passage openings of the same diameter, wherein the pairs of passage openings have different diameters, each corresponding to a light exit aperture of a cover, and as light guiding arrangements at least two cylindrical reflectors with different diameters, each corresponding to a light exit aperture of a cover, whereby at least four construction variants can be produced, which differ from each other at least in the following ways.Design variant 1 can have a first cover, in particular with a first light exit aperture, and a first of the aperture arrangements as light guiding arrangements. Design variant 2 can have a second cover, in particular with a second light exit aperture, and a second of the aperture arrangements as light guiding arrangements. Design variant 3 can have the first cover with a first of the cylindrical reflectors as a light guiding arrangement, and design variant 4 can have the second cover with a second of the cylindrical reflectors as a light guiding arrangement. The two different reflectors can each have different diameters.In relation to the light exit aperture, this means in particular that the light guiding arrangements each have the same diameter, for example the round openings of the aperture arrangements or the diameter of the reflectors, as the corresponding light exit aperture of a cover.

[0021] This offers the advantage that the lighting device is designed to be compatible with various measuring devices.

[0022] Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawings. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the figures alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0023] This shows: Fig. 1 a schematic, perspective view of the exterior of a lighting device according to the invention with display and operating device on a front side; Fig. 2 a schematic, perspective view of the lighting device according to the invention with display and operating device on a front side and mounting device on a rear side; Fig. 3 a schematic representation of an arrangement of the lighting device according to the invention on a measuring device with material to be examined; Fig. 4 a schematic sectional view of the lighting device according to the invention during operation of the lighting device; and Fig. 5 another schematic sectional view of the lighting device according to the invention.

[0024] In the figures, identical or functionally equivalent elements are provided with the same reference symbols.

[0025] Fig. Figure 1 shows a schematic, perspective view of the exterior of a lighting device 10, looking towards the front of the lighting device 10, on which a display and control device 17 may be arranged. As in Fig. As shown in Figure 1, the display and control unit 17 can be designed as a touch-sensitive display, also called a touch display. As shown in Fig. As shown in Figure 1, the front panel with the display and control unit 17 can be angled to ensure that the display content of the display and control unit 17 is particularly easy for the user to read. A control unit 23 can be operated via the display and control unit 17, by means of which the user can adjust the electrical power, voltage, and / or current with which a light source is to be operated. The light source 10 can include a power measuring device, which may have a power sensor by means of which the actual electrical power, voltage, and / or current with which the light source is currently being operated or supplied during operation can be determined or measured.The measured values ​​detected by the power measuring device can be output to a user via the display and control unit 17. On the front, for example, a storage compartment 16 can be arranged next to the display and control unit 17. This compartment can define a cavity for storing cables, particularly power cables, which can supply power to the display and control unit 17 and / or the light source. A reversibly, and in particular non-destructively, removable cover 14 with a light emission opening 15 can be arranged on or enclosed by the top of the light unit 10. The light unit 10 can be designed to be portable, for example, so that it can be carried by a person.For this purpose, the lighting device 10 can have a longitudinal dimension 11 in a longitudinal direction, a transverse dimension 12 in a transverse direction, and a vertical dimension 13, each of which may not exceed 50 cm, and in particular not exceed 30 cm. The housing of the lighting device 10 and / or the cover 14 may be made of plastic and, in particular, may be 3D printed.

[0026] Fig. Figure 2 shows a schematic, perspective view of the exterior of the lighting device 10 with the display and control unit 17, the storage compartment 16, the cover 14, the light emission opening 15 and a mounting device 18. The mounting device 18 can be, as shown in Fig. The mounting device 18, as shown in Figure 2, can be arranged on the housing opposite the front side in the longitudinal direction or on the rear side encompassed by the housing. The mounting device 18 can, in particular, be formed integrally with the housing, especially with the rear side of the housing, and can, for example, be 3D-printed together with the housing.

[0027] Fig. Figure 3 shows a schematic representation of an arrangement of the lighting device 10 on a measuring device 20, wherein a material 19 to be examined for its light properties can be arranged between the lighting device 10, in particular between the cover 14 and the measuring device 20. In this arrangement, the lighting device 10 can be fixed relative to the measuring device 20 and the material 19 by means of the mounting device 18. The measuring device 20 can, for example, be mounted as shown in Fig. Figure 3 shows a so-called integrating sphere. During a measurement or during operation of the lighting device 10 in this arrangement, light beams provided by the lighting device 10 can be emitted from a light exit aperture 15 (not in Fig. 3 shown) exit the lid 14, penetrate the material 19 for example and subsequently or in the direction of the beam after the material 19 the light rays 21 can enter the measuring device 20 or the integrating sphere via an adjustable aperture 22.

[0028] Fig. Figure 4 shows a schematic sectional view of an imaginary section through the lighting device 10 during operation of the lighting device 10. As in Fig. As shown in Figure 4, the lighting device 10 can be divided into two sections by means of the housing. The first section is an electronics section 31, in which the display and operating unit 17, the storage compartment 16, and the control unit 23 can be arranged. The storage compartment 16 and the display and operating unit 17 can be enclosed by a display cover 24, which can be removed from the housing without damage and which can form the front. The control unit 23 can be implemented as a microprocessor circuit, such as an Arduino®, and can be attached to a mounting wall 33 in the electronics section 31. A second section or area of ​​the lighting device 10 can be designated as the light section 32. The light section 32 can at least partially define a receiving space 29, which can be defined vertically by the cover 14.A holding device 34 for receiving a sample holder 36, on which a light source can be fixed, can be arranged internally on a bottom side or bottom wall of the housing and have two fixed mounting rails 35, in particular formed integrally with the housing, into which the sample holder 36 with the light source can be inserted. The sample holder 36, inserted into the mounting rails 35, can, for example, be inserted into the holding device 34 along the mounting rails 35 up to a stop provided by each of the mounting rails 35 and then fixed in a translational or transverse direction by means of a holder 37 of the holding device 34. For this purpose, the holding device 34 can include one or more magnets by means of which the holder 37 can be fixed to the holding device 34 and the sample holder 36 can thus be fixed immovably in all three spatial directions.The holding device 34 and the lighting device 10 are thus designed to accommodate and operate different light sources within a sample holder 36 in the receiving chamber 29. The different light sources can, for example, emit light with different color coordinates or different colors. The electronics section 31 and the lighting section 32 can be spatially connected via a cable passage 30, through which electrically conductive cables, for example, for supplying the sample holder 36 with current via the light source, can be routed. The cover 14 can be attached to the housing by means of a cover holder 25 in a non-destructively reversible manner.For this purpose, for example, the lid 14 can have a first magnet and the lid holder 25 a second magnet, whereby, when the lid 14 is mounted on the housing, the two magnets can attract each other, in particular contact each other, and thus hold the lid 14 attached to the housing. A light guide arrangement 26 can be arranged in the receiving chamber 29 in the vertical direction between the sample holder 36 with the light source and a light emission opening 15 of the lid 14. As in . Fig. As shown in Figure 4, the light guiding arrangement 26 can be configured as an aperture arrangement with two parallel apertures, each of which can have passage openings 27, 28. The light source, the two passage openings 27, 28, and the light exit aperture 15 can be arranged collinearly, i.e., on a line or straight line, whereby one direction of extension or length of the straight line can run along a light guiding direction or intended beam direction. The light guiding arrangement 26, for example, the one shown in Figure 4, can be configured as a diaphragm arrangement with two parallel apertures, each of which can have passage openings 27, 28. The light source, the two passage openings 27, 28, and the light exit opening 15 can be arranged collinearly, i.e., on a line or straight line, with one direction of extension or length of the straight line running along a light guiding direction or intended beam direction. Fig. The aperture arrangement shown in Figure 4 can be designed to be interchangeable or replaceable and, in particular, can be removed vertically from the receiving chamber 29 when the cover 14 is open or removed, and replaced by a second aperture arrangement or by a cylindrical reflector. It is specifically provided that the diameter of the light exit aperture 15, designed as a round recess, corresponds to the diameter of the cylindrical reflector and / or the diameter of the passage openings 27, 28, also designed as round recesses. This can mean that the diameter of the light exit aperture 15, the first passage opening 27, and the second passage opening 28 are the same, for example, 10 mm. As shown in Figure 4, the diameter of the light exit aperture 15, the first passage opening 27, and the second passage opening 28 are the same, for example, 10 mm. Fig. As shown in Figure 4, the aperture arrangement ensures that only light rays 21 emitted by the light source can pass through the two apertures 27, 28 and through the light exit aperture 15, provided these rays deviate only up to a certain degree, for example, 1 to 4 degrees, from the intended beam direction. Light rays 21 deviating more significantly are blocked as shown in Figure 4. Fig. 4 are held back by the apertures and / or by the cover 14 or collide with them and cannot pass through the openings 27, 28 and / or through the cover 14, in particular through the light exit opening 15.

[0029] Fig. Figure 5 shows another schematic sectional view of an imaginary section through the lighting device 10 with a section plane perpendicular to a transverse direction of the lighting device 10. As in Fig. As shown in Figure 5, the mounting device 18, arranged on the outside of a rear side of the housing, can have at least one bore through which at least one screw can be passed, by means of which the lighting device 10 can be attached, in particular for mounting on a measuring device 20. As shown in Fig. As shown in Figure 5, the cover 14 in the area immediately surrounding the light exit aperture 15 can be designed as a variable or adjustable aperture 22.

[0030] A particularly preferred embodiment is described below.

[0031] The lighting device 10 offers the following advantages. The light source, which can also be referred to as the lamp, can be interchanged by fixing the different light sources on separate sample holders 36. Reproducible measurement results can be achieved with the fixed (but also interchangeable) light source, which can be an LED (Light Emitting Diode). The LED current for operating the lamp and / or its brightness can be adjusted in small increments using a suitable DC LED driver. Particularly easy operation of the lighting device 10 can be achieved through a user interface touch display, which can also be referred to as a display and control device 17, for example, by allowing for small-scale current adjustment.Live feedback of the measured current value on the display, provided by an integrated current sensor (also known as a power sensor), can be available. Various inserts or light guide arrangements 26 can be provided for optimal light focusing and / or shaping (white reflector and black aperture or aperture arrangement). Adaptation to the geometry of the respective measuring device (also known as measuring equipment 20) can be achieved through various box closures or covers 14 with openings adapted to the measuring devices, such as the light exit aperture 15, and geometries in the covers. A color selection for the components (black / white) can be implemented to suit the lighting requirements. The lighting device 10, designed as a portable box, can be mobile and flexible, with a connection to a power outlet.This allows for particularly fast measurement setup and measurements in conjunction with various measuring instruments. The light box, which can also be referred to as a lighting device 10, can be used as an aid in light source and material measurements with regard to various optical quantities and / or parameters such as transmission and / or chromaticity (color).

[0032] Technically, the lighting device 10 can be implemented as follows. The light box can include a light source, which can also be referred to as a light source, such as an interchangeable LED; a holder 36, which can also be referred to as a sample holder and is attached in all spatial directions; at least two different inserts or light guiding arrangements 26 for focusing and / or guiding the light, such as a double aperture or pinhole arrangement or a reflector; three different magnetically attachable covers 14 for optimal compatibility with the respective (light) measuring instruments; a control unit 23 with a touch display for controlling the brightness and / or current of the light source; an integrated current sensor or power sensor that reports the applied and / or set current during operation; and a mounting device 18 for positioning the light box in front of and / or on the measuring instrument.

[0033] The materials 19 to be examined are placed on the light aperture, which can also be referred to as the light exit aperture, of the light box. By placing the light aperture or the material 19 against a measuring device, the light values ​​can be measured reproducibly (reproducibility through fixing the light source in all spatial directions). The light box can therefore also be used for the visual assessment of the examined materials. The integration of all components within the housing allows for a flexible and / or mobile measurement setup, as the light box can be connected to a standard 230V socket using a single plug. The current and voltage can be adjusted to the appropriate values ​​for the light source by the electronics or control unit 23 within the light box. The brightness of the light source can be conveniently adjusted in very small increments via the touch display integrated into the light box.Each LED or light source can be glued to its own sample holder 36 and thus fixed in place. Within the light box, the sample holder 36 can be fixed in all three spatial directions by two slide-in rails, which can also be referred to as mounting rails 35, with stops, and by a magnetically attachable and detachable mounting rail or holder 37 of the holding device 34, in order to ensure reproducible measurement results (no slippage of the light source and identical positioning of the light source for every measurement, even after removing and reinserting the light source). Various inserts and / or attachments allow the light box to be optimally adapted to specific measurements.Two or three different covers 14 with different hole diameters or diameters of the respective light exit aperture 15 for the exit of the light beam from the light source located in the box can be provided, as well as two different inserts for focusing and / or guiding the light beam or light beams 21. For example, an internally white cylindrical reflector, for instance as a light guiding arrangement 26, can be used for the visual assessment of materials 19 placed on the light box in order to diffuse as much light as possible through the light exit aperture. A black double aperture or aperture arrangement with respective aperture diameters or diameters of the passage openings 27, 28 can be matched to the diameter of the associated cover.This allows the light to be focused, resulting in a highly directed beam exiting the light outlet 15, and ensuring that as much of the light exiting the light box as possible enters the measuring device. Convenient and precise adjustment of the light source's brightness / current via a touchscreen or display 17 is provided, and feedback and verification of the set current value during operation via an integrated current sensor.

[0034] Overall, the examples show how the lighting device 10 can provide a metrological aid for measuring and visually assessing material and light source combinations.

Claims

[1] Lighting device (10) for providing light for measuring the light properties of a material (19) or a light source, comprising a housing which at least partially defines at least one receiving space (29), a holding device (34) for attaching a light source in the receiving space (29), and a cover (14) which is held on the housing by means of a cover holder (25) in a non-destructively reversible manner, wherein the cover (14) has a first magnet and the housing has a second magnet, and in the state of the cover (14) being mounted on the housing, the two opposing magnets attract each other, in particular contact each other, and thus hold the cover (14) attached to the housing, and the cover (14) has a light emission opening (15) through which light emitted from the light source can be emitted from the lighting device (10) to act on the material (19).with a light guiding arrangement (26) arranged between the holding device (34) and the cover (14), through which light emitted by the light source can be guided to the light exit aperture (15), and with a control device (23) for controlling a power supply to the light source, wherein the holding device (34) is designed to receive a sample holder (36) for fixing the light source, wherein the sample holder (36) can be removed from the holding device (34) non-destructively and reversibly, wherein the holding device (34) has two mounting rails (35) each with a stop, into which the sample holder (36) can be inserted and moved along the mounting rails (35) up to the two stops and can be fixed immovably in the translational direction by means of a holder (37) that can be magnetically attached to the holding device (34), for which purpose the holding device (34) comprises one or more magnets,by means of which the holder (37) can be fixed to the holding device (34), [2] Lighting device (10) according to claim 1 characterized by a power measuring device comprising a power sensor for measuring the electrical power and / or the electrical current and / or the electrical voltage supplied to the light source when the lighting device (10) is operated. [3] Lighting device (10) according to any one of the preceding claims with reference to claim 2, characterized by , that the housing has a touch-sensitive display and operating device (17) for operating the control device (23) and / or for outputting measured values ​​from the power measuring device. [4] Lighting device (10) according to any one of the preceding claims, characterized by, that the light guidance arrangement (26) is designed as an aperture arrangement with at least two planes, each with a pinhole aperture having a respective passage opening (27,28), and that the light exit opening (15) and the passage openings (27,28) are arranged collinearly. [5] Lighting device (10) according to one of claims 1 to 3, characterized by , that the light guidance arrangement (26) is designed as a cylindrical reflector, the central axis of which can be arranged collinearly with the light exit aperture (15). [6] Lighting device (10) according to any one of the preceding claims, characterized by , that the housing has a mounting device (18) on the outside. [7] Lighting device (10) according to any of the preceding claims, characterized by , that the lighting device (10) is designed as a portable lighting device (10). [8] Lighting device (10) according to any of the preceding claims, characterized by, that the lighting device (10) has a power plug that can be connected to a household electrical network providing 230 volts for the operation of the lighting device (10). [9] Modular system for manufacturing several variants of a lighting device (10) according to one of the preceding claims, wherein the modular system comprises at least the housing, the holding device (34), the control device (23), at least two covers (14) each with a light emission opening (15), wherein the light emission openings (15) have different diameters, as light guiding arrangements (26) at least two aperture arrangements each with a pair of passage openings (27, 28) of the same diameter, wherein the pairs of passage openings (27, 28) have different diameters, each corresponding to a light emission opening (15) of a cover (14), and as light guiding arrangements (26) at least two cylindrical reflectors with different diameters, each corresponding to a light emission opening (15) of a cover (14),wherein at least four construction variants can be produced, each characterized by at least the following, wherein each construction variant comprises a lid holder (25), holder rails (35), a sample holder (36) and a holder (37) according to claim 1:, • Construction variant 1: by means of a first of the covers (14) with a first of the aperture arrangements as a light guiding arrangement (26); • Construction variant 2: by means of a second of the covers (14) with a second of the aperture arrangements as a light guiding arrangement (26); • Construction variant 3: through the first of the covers (14) with a first of the cylindrical reflectors as a light guiding arrangement (26); and • Construction variant 4: through the second of the covers (14) with a second of the cylindrical reflectors as a light guiding arrangement (26).

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