Daylight hand lamp for inspecting painted surfaces, especially during paint repair work on motor vehicles

Abstract

Daylight hand lamp (1) for inspecting painted surfaces, particularly in the area of ​​paint repair work on motor vehicles, wherein the daylight hand lamp (1) has a light source (7) by means of which a light beam (6) can be generated, wherein the light beam (6) forms a beam cross-sectional area (11) at a distance of 30 cm ± 0.5 cm from the light source (7) along a beam axis (10) which is perpendicular to the beam axis (10), wherein the beam cross-sectional area (11) has at least a central core area (13) with an inner diameter of at least 16 cm, wherein at least in the core area (13) the light has a general color rendering index (CRi) with a value greater than 95, wherein the illuminance in the entire core area (13) is greater than 5000 Ix, wherein the beam cross-sectional area (11) additionally has an inner edge area (14) which surrounds the core area (13),wherein the illuminance in the inner edge region (14) decreases to at least 1000 ×, and wherein the light spectrum is at least homogeneous across the beam cross-sectional area (11), , that in a spectral range with a wavelength of 400 to 700 nm, the mean daylight deviation is less than 20% at least in the core and inner edge region (13, 14) and / or that in a spectral range with a wavelength of 400 to 700 nm the mean value of a spectral stability factor with reference to the beam center is less than 10% at least in the core and inner edge region (13, 14).

Description

[0001] The invention relates to a daylight hand lamp for inspecting painted surfaces, in particular in the context of paint repair work on motor vehicles, wherein the daylight hand lamp has a light source by means of which a light beam can be generated which has a daylight-like light spectrum and a high luminous intensity. State of the art

[0002] A visual inspection of painted surfaces is required for a number of painting jobs. This is especially true for automotive refinishing. A visual color comparison of the newly painted areas with the original surface areas is necessary because, despite detailed mixing specifications for paints and coatings by the paint industry, color variations can occur in practice. Furthermore, a visual comparison of color charts, color swatches, or reference panels with previously painted surfaces is often performed before the painting process to determine the correct color for the new paint job.

[0003] Besides checking color tones, a visual inspection also serves to identify other properties or defects of a painted surface. Examples include undesirable clouding, cratering, pinholes, orange peel, fisheye, sparkling, metallic effects, or variations in coating thickness, etc.

[0004] In the case of paint repairs on motor vehicles, it is also important to consider that the painted vehicle will later be assessed and accepted by the customer outdoors under natural light. Therefore, it is required that the painter inspect the painted surfaces of motor vehicles outdoors under natural daylight. However, since painting work, especially on motor vehicles, is carried out in enclosed spaces (paint booths) for environmental protection reasons and to shield the painting process, there is a need for at least a preliminary inspection of the painted surface directly in the paint shop or workshop. Inspection in enclosed spaces under artificial light also has the advantage of being carried out under constant, reproducible lighting conditions. In contrast, lighting conditions outdoors vary due to various influencing factors (weather, time of day, season, etc.).

[0005] For this reason, daylight handheld lamps were developed that can produce light as similar as possible to daylight with a relatively high luminous intensity, allowing for a meaningful assessment of painted surfaces. After completing the painting process, the painter can illuminate the painted surface with the handheld lamp, check the result of their work, and make any necessary touch-ups or corrections.

[0006] From DE 10 2014 018 940 A1, such a daylight handheld lamp for inspecting painted surfaces in the automotive repair sector is known, characterized by a daylight-like light spectrum at high luminous intensity. A wide variety of paint defects can be detected when inspecting surfaces with such a handheld lamp. Despite the high luminous intensity, some defects, color variations, etc., cannot be detected, or can only be detected with great difficulty, in the artificial light of the previously known handheld lamp. Object of the invention

[0007] The invention aims to provide a daylight hand lamp for inspecting painted surfaces, with the aid of which the detectability of color differences or defects on painted surfaces is facilitated or improved when inspecting under the artificial light of the daylight hand lamp. Description of the invention

[0008] The problem is solved by a daylight hand lamp with the features of claim 1.

[0009] The daylight hand lamp according to the invention has a light source by means of which a light beam or light bundle can be generated which forms a beam cross-sectional area at a distance of 30 cm ± 0.5 cm from the light source along a beam axis, which runs perpendicular to the beam axis.

[0010] A distance of 30 cm ± 0.5 cm from the light source is used because it falls within the range at which a painter typically holds a handheld lamp over the surface to be inspected. Thus, the properties of the beam cross-sectional area defined above correspond to a reference light spot or patch that would appear on a flat surface when the daylight handheld lamp according to the invention is positioned at a distance d of approximately 30 cm above the surface. The lamp is oriented such that the light beam strikes the surface perpendicularly.

[0011] It goes without saying that in actual use, the handheld lamp can be held in relation to the surface being inspected in such a way that the light beam strikes the surface at any angle. For example, when inspecting metallics, sparkling materials, etc., an angled illumination is preferable.

[0012] The distance of 30 cm ± 0.5 cm is measured from the outer surface of the last optical element of the light source that the light beam passes through before leaving the handheld lamp. This could, for example, be a thin cover disc of the light source.

[0013] The beam cross-sectional area or reference light spot defined in this way has at least one central core area with an inner diameter of at least 16 cm. In this core area, the light from the daylight handheld lamp according to the invention has a general color rendering index (CRI) greater than 95. Furthermore, the illuminance in the entire core area is greater than 5000 ×. Therefore, at a distance of 30 cm, the daylight handheld lamp can generate a bright light spot with a daylight-like light spectrum that also has a sufficient extent (>> 16 cm). These are important prerequisites for the daylight handheld lamp to be used for a reliable and meaningful optical inspection of painted surfaces.

[0014] The invention is based on the understanding that a significant improvement in the detectability of paint defects occurs when the properties of the generated light are optimized in an inner edge region directly surrounding the core area, according to the invention. In this inner edge region, the illuminance already decreases to 1000 lx. The inner edge region is therefore defined as the region that lies radially between the core area and the region where the illuminance falls below 1000 lx. Consequently, the inner edge region is surrounded by an outer edge region in which the illuminance decreases to the outer boundary of the beam cross-sectional area or the light spot.

[0015] The decisive factor for the daylight hand lamp according to the invention, which has surprisingly good properties for the inspection of painted surfaces, is that the light spectrum across the beam cross-sectional area is at least so homogeneous that in a spectral range with a wavelength of 400 to 700 nm, the average daylight deviation in the core and inner edge area is less than 20%.

[0016] Alternatively or additionally, the light spectrum across the beam cross-sectional area is at least so homogeneous that in a spectral range with a wavelength of 400 to 700 nm, the mean value of a spectral stability factor based on the beam center in the core and inner edge region is less than 10%.

[0017] The limitations of the spectral range between wavelengths of 400 to 700 nm result from the realization that it is essentially the light of this spectral range that influences the color impression of the painted surfaces.

[0018] The mean daylight deviation value, or the spectral stability factor relative to the center of the core area, are values ​​that, unlike, for example, the general color rendering index Ra, are particularly well suited for quantifying the homogeneity of the light impression, especially the color impression, when inspecting painted surfaces. This area corresponds to the spectral range that is essentially perceptible to the eye.

[0019] As is well known, the general color rendering index Ra (CRi value) is a metric used to describe the quality of color rendering of light sources with the same correlated color temperature. The general color rendering index incorporates the values ​​of the first eight test colors according to DIN 6169. However, because differences or changes in individual test colors can compensate for each other, and therefore the general color rendering index may hardly change despite visually perceptible hue shifts, it is not well suited to describing hue shifts of the same light source within a single light spot.

[0020] In the inner edge region, the illuminance has already decreased significantly. Therefore, it might be assumed that this dimly lit edge region would not have a significant impact on the reliability of visual inspection results. However, it has been shown that, due to the nature of the human eye, the light characteristics of the inner edge region unexpectedly have a strong influence on the visual perception of optical differences in the illuminated surface area. It is particularly important that, according to the invention, the light spectrum is homogeneous across both the core region and the inner edge region.

[0021] Preferably, the mean daylight deviation at a point on the beam cross-sectional area is calculated by determining a light spectrum normalized to the maximum intensity at that point. Then, the difference between the determined light spectrum and a daylight spectrum normalized to the maximum intensity is calculated. Finally, the mean of the differences is calculated over the spectral range from 400 to 700 nm.

[0022] Preferably, the average value of the spectral stability factor is calculated with respect to the center of the beam at a point on the beam cross-sectional area such that a light spectrum normalized to the maximum intensity is determined at that point. Preferably, only the maximum intensity in the visible wavelength range of 400 to 700 nm, and more preferably only a wavelength range between 380 and 580 nm, is considered during normalization.

[0023] The difference between the measured light spectrum and a light spectrum normalized to the maximum intensity, measured at the center of the beam, is then calculated. Finally, the average of these differences is calculated over the spectral range from 400 to 700 nm. This average represents the average of the spectral stability factor.

[0024] An inner diameter of 16 cm for the bright (>5000 ×) and daylight-like (CRi > 95) core area represents a minimum requirement for the generated light beam. In a particularly preferred embodiment, the core area has an inner diameter of at least 20 cm, preferably 24 cm.

[0025] In a particularly preferred embodiment, the core area is even brighter and the illuminance in the core area is greater than 6000 lx, preferably greater than 7000 lx, and even more preferably greater than 8000 lx.

[0026] The light from the beam cross-sectional area or the generated light spot is characterized by an even higher homogeneity if the mean daylight deviation in the core and inner edge area is less than 18%, especially less than 16%.

[0027] An embodiment offering the same advantage is characterized by an alternative or additional change in the mean daylight deviation in the core and inner edge regions by less than 6%, preferably less than 4%. It is advantageous if the mean daylight deviation in the core and inner edge regions is low. However, it is also advantageous if the (low) mean daylight deviation remains relatively constant, as this in turn ensures that the light spectrum changes only minimally.

[0028] Furthermore, in a particularly preferred embodiment, the mean value of the spectral stability factor, based on the beam center in the core region and inner edge region, is even less than 8%, in particular less than 6%.

[0029] In a particularly preferred embodiment, the illuminance in the inner edge region decreases to 500 Ix, preferably to 300 Ix, but the inner edge region still meets the requirements for the homogeneity of the light spectrum.

[0030] To avoid unwanted interference effects caused by an asymmetrical spot shape when inspecting painted products, the generated light beam has a circular cross-section. The intensity and light spectrum are constant in the circumferential direction. The core area is circular. The inner edge area is formed by an annular region surrounding the circular core area. Radially adjacent to the annular inner edge area is a very dim, annular outer edge area.

[0031] In the case of a particularly preferred intensity distribution, the inner edge region has a width greater than 4 cm, preferably greater than 6 cm, or even more preferably greater than 8 cm in the radial direction.

[0032] In particular, this allows a daylight hand lamp to create a light spot at a distance of 30 cm, the core and inner edge of which have a total diameter of at least 30 cm, preferably 40 cm, or even more preferably 50 cm.

[0033] Another parameter used to describe the color of artificial light is its color temperature. Preferably, in the daylight handheld lamp according to the invention, the color temperature of the light is greater than 5500 K and / or less than 6500 K, at least in the core and inner edge regions.

[0034] For example, a cost-effective halogen lamp could be used as the light source for the light fixture.

[0035] In a particularly preferred embodiment, the luminaire comprises one or more light-emitting diodes (LEDs) as the light source. LEDs are characterized by short start-up times, low power consumption, and a long service life.

[0036] To create a daylight-like light spectrum, it can preferably be provided that at least one light-emitting diode emits light with a light spectrum that differs from the light spectrum of another light-emitting diode, so that the superposition of the light spectra results in an overall spectrum that is as similar as possible to daylight.

[0037] In a particularly preferred embodiment, the luminaire comprises several light-emitting diodes as the light source, wherein the respective light-emitting diodes emit light with the same daylight-like light spectrum.

[0038] A variant of the invention is characterized by a particularly compact light source, in which one or more COB light-emitting diodes or COB LEDs are provided as the light source.

[0039] To ensure a high degree of similarity between the light spectrum of the generated light and that of daylight, a luminaire has proven effective in practice that incorporates one or more light-emitting diodes (LEDs) as its light source, which contain a color-imparting luminescent material, preferably a phosphor-based color-imparting luminescent material. Several different colored phosphors can be used to further improve the light spectrum.

[0040] One embodiment of the invention is characterized by particularly good optical properties, in which a high homogeneity of light intensity is achieved by the luminaire comprising several light-emitting diodes as a light source, wherein the light-emitting diodes are each provided with a lens.

[0041] A particularly homogeneous intensity distribution is achieved by the luminaire comprising several light-emitting diodes as the light source, wherein all light-emitting diodes are arranged in one plane, wherein several, in particular nine, light-emitting diodes are arranged uniformly on an outer circular path and several, in particular three, light-emitting diodes are arranged uniformly on an inner circular path.

[0042] For the handling of the daylight hand lamp according to the invention, it is advantageous if the daylight hand lamp is designed as a cordless, battery-operated lamp. A painter can guide the hand lamp along the surface to be inspected without hindrance from connecting cables.

[0043] In certain applications, such as inspecting highly reflective or bright surfaces, it is advantageous to be able to reduce the light intensity of the light source. For this reason, in a particularly preferred embodiment, the light intensity of the daylight handheld lamp is adjustable, at least dimmable within the range of 50–100% light intensity.

[0044] Further embodiments of the invention are the subject of the dependent claims and the exemplary embodiments of the invention described below. The invention will now be explained in more detail with reference to exemplary embodiments and the accompanying figures. Specifically, the figures show: Fig. 1. A side view of a daylight hand lamp including a schematic representation of the generated light beam, Fig. 2 the cross-sectional area of ​​the light ray according to Fig. 1 in a schematic representation, Fig. 3 a schematic representation of the measuring device for measuring the light beam of a daylight hand lamp, Fig. 4 the illuminance of the daylight hand lamp according to Fig. 1 depending on the distance D M to the center of the beam, Fig. 5 the illuminance as a function of the distance rM to the beam center according to Fig. 4 only in the outer distance area, Fig. 6 a comparison of the standardized light spectrum of daylight and the standardized light spectrum of the daylight hand lamp according to Fig. 1, Fig. 7 the difference of the normalized light spectra from Fig. 6, Fig. 8 the mean daylight deviation of the daylight hand lamp according to Fig. 1 as a function of the distance rM to the beam center in percent, Fig. 9 the mean value of the spectral stability factor of the daylight hand lamp according to Fig. 1 depending on the distance rM to the beam center in percent and Fig. 10 a front view of the head of the daylight hand lamp according to Fig. 1.

[0045] In Fig. Figure 1 shows a daylight hand lamp 1 for inspecting painted surfaces, particularly during paint repair work on motor vehicles. The hand lamp 1 has a head 2, a handle 3, and a detachably attached accumulator 4, in particular a lithium-ion accumulator, at the lower end of the handle 3. The head 2 has a light outlet opening 5 on its front, through which a light beam 6 can emerge. A light source 7 is arranged in the head 2 to generate the light beam 6. Fig. Figure 1 shows the head section 2 partially cut away in the area of ​​the light outlet opening 5 in order to show at least part of the light source 7.

[0046] A control element 8 is provided on the back of the headpiece 2, by means of which the luminous intensity of the generated light beam 6 can be adjusted, for example, in a range from 50 to 100% of the maximum luminous intensity. On the side opposite the control element 8 and below the headpiece 2, another control element 9 is arranged for switching the hand lamp 1 on and off.

[0047] Furthermore, in Fig. Figure 1 schematically depicts the light beam 6 produced by the hand lamp 1, which propagates along a beam axis 10. At a distance d of 30 cm ± 0.5 cm from the light source 7, the light beam 6 forms a beam cross-sectional area 11 perpendicular to the beam axis 10. This distance is measured from the outer surface of the last optical element of the light source 7 that the light beam 6 passes through before leaving the hand lamp 2. In this case, this optical element is a thin cover plate of the light source 7.

[0048] In Fig. Figure 2 shows the circular beam cross-sectional area 11 in a top view. The beam cross-sectional area 11 and its light properties correspond to the properties of a reference light spot that is formed on a flat surface using the handheld lamp 1 when the light source 7 of the handheld lamp 1 is held at a distance of 30 cm above the surface and the light beam 6 is directed perpendicularly to the surface.

[0049] The beam cross-sectional area 11, or the reference light spot, can be divided into three regions. Starting from the beam center 12, the beam cross-sectional area 11 has a central circular core region 13, an annular inner edge region 14, and an annular outer edge region 15. Regions 13, 14, and 15 are in Fig. 2 not shown strictly to scale.

[0050] The central core area 13, for example, has an inner diameter of at least 16 cm. At least in core area 13, the light has a general color rendering index (CRI) greater than 95. The illuminance throughout core area 13 is greater than 5000 ×.

[0051] In the case of an exemplary definition of the areas, the core area 13 transitions into the inner edge area 14 when the illuminance falls below 5000 lx. The inner edge area 14, in turn, transitions into the very dim outer edge area 15 when the illuminance has decreased to at least 1000 lx.

[0052] The color temperature of light beam 6 is greater than 5500 K, at least in the core and inner edge area 13, 14.

[0053] The light produced by the handheld lamp 1 is characterized by its homogeneous light spectrum, at least in the core and inner edge regions 13, 14. This is demonstrated by the fact that, within a spectral range with a wavelength of 400 to 700 nm, the average daylight deviation in the core and inner edge regions 13, 14 is less than 20%.

[0054] Furthermore, in the spectral range with a wavelength of 400 to 700 nm, the mean value of a spectral stability factor based on the beam center in the core and inner edge region 13, 14 is also less than 10%.

[0055] The following describes how the light beam 6 of the hand lamp 1 is measured and how the mean daylight deviation is ultimately calculated from the measurement results ( Fig. 7) and the mean value of the spectral stability factor relative to the beam center 12 ( Fig. 8) is determined.

[0056] In Fig. Figure 3 shows an exemplary measuring apparatus 20, by means of which the light properties of the hand lamp 1 can be determined. The hand lamp 1 is preferably attached to a tripod 22 at a distance d of 30 cm above a detector 21 (specifically the lens of the detector).

[0057] Detector 21 was a tested and calibrated MK350S spectral measuring device from UPRtek, which has a CMOS linear image sensor (spectral bandwidth: approx. 12 nm (half bandwidth), receptor size: diameter 6.6 mm + / - 0.1 mm, measuring range: 20 - 70,000 Ix, wavelength range: 380 - 780 nm, integration time span: 6 - 5,000 ms).

[0058] The receptor or measuring field of detector 21 is in Fig. Figure 3 shows two positions as examples. In the first position, the receptor is centered on the midpoint 12 of the light beam 6. In this position, the light properties at the beam center 12 are determined. Subsequently, the detector 21 is moved radially outward by 2 cm on the flat support surface 23. The light properties at this point on the beam cross-section, or the reference light spot, are determined. This process continues in 2 cm increments until a distance r is reached. M is reached from 24 cm from the center, i.e., a point is measured that lies on a circular path around the center 12, which has a diameter of 48 cm. In Fig. 3 is, as an example, the second position of detector 21, a position with a distance r. M from 24 cm to the beam center 12 shown.

[0059] All measurements were carried out under uniform conditions in a darkened room. Between measurements, the handheld light 1 was switched off to avoid measurement errors caused by different switch-on times.

[0060] In the Fig. 4 and Fig. 5 is the illuminance determined in this way as a function of the distance r. u the measuring station from the beam center 12 (r M = 0 cm). It is evident that the illuminance decreases continuously from the center of the beam 12 outwards. For inspecting painted surfaces, it is advantageous that the illuminance decreases gradually and not abruptly.

[0061] It's worth noting that the illuminance of a handheld lamp using LEDs as its light source has a particularly smooth transition at the edges. Such a smooth transition can also be achieved with a halogen lamp, for example. However, the light from a halogen lamp, in known models, has the disadvantage that the edges of the beam exhibit a different light spectrum (e.g., a reddish tint). This colored corona is problematic when inspecting painted surfaces.

[0062] Furthermore, it can be seen that the illuminance of the exemplary hand lamp 1 only increases at a distance r M from approximately 12 cm to below 5000 ix. Therefore, if core area 13 is defined as having an illuminance greater than 5000 ix throughout its entire area, the resulting core area 13 has an inner diameter of approximately 24 cm.

[0063] Another perspective or definition of core area 13 reveals, based on Fig. 4, that in the exemplary hand lamp the illuminance in a core area 13 with a diameter of 16 cm (r M = 8 cm) even larger than 10000 Ix.

[0064] Advantageously, the hand lamp 1 has a maximum illuminance - in the center of the beam 12 - of over 16000 Ix, specifically of over 20000 Ix.

[0065] Furthermore, the Fig. 4 and Fig. 5, that the inner boundary region 14, in a definition in which the inner boundary region 14 ends when the illuminance falls below 1000 Ix, at a distance r M to the center of the beam 12 of approximately 17 cm.

[0066] However, definitions are also applicable in which the inner boundary region 14 is the region in which the illuminance decreases to 500 ×, preferably to 300 ×. In this case, the inner boundary region 14 extends to a distance r. M of approximately 19 cm or 21 cm. Accordingly, the inner edge area 14 can have a width greater than 4 cm, preferably greater than 6 cm, or even more preferably greater than 8 cm.

[0067] To determine the daylight spectrum, measurements of daylight were taken with the UPRtek MK350S detector under different weather conditions, times of day, and orientations, and a daylight spectrum averaged from these measurements was calculated. This calculated daylight spectrum was then compared with the values ​​of standard illuminant class D (daylight), in particular D65 (6500 K) of the CIE standard colorimetric system. Only minor deviations were found, which have no relevant influence on the parameters calculated based on the daylight spectrum.

[0068] In Fig. Figure 6 shows the light spectra of daylight and the light beam of the hand lamp at the center of the beam 12, each normalized to its maximum intensity. The good agreement with the daylight spectrum is evident, which is also due to the fact that the light beam is in the center of the beam. Fig. This becomes clear in diagram 7. Fig. 7 is the difference in percent of the in Fig. The 6 normalized spectra shown in the relevant range of 400 to 700 nm can be taken from the relevant range.

[0069] Based on the displayed differences, the average value was calculated over the range of 400 to 700 nm. This yields the average daylight deviation of light beam 6 at beam center 12, expressed as a percentage. The average daylight deviation of light beam 6 is calculated analogously for the other measured distances r. M The beam center 12 was determined. The result is Fig. 8 shows the mean daylight deviation as a function of the distance r M shows.

[0070] The average daylight deviation is less than 20% across the entire measured distance range, and specifically even less than 18%. Up to a distance r M At a height of approximately 22 cm, the average daylight deviation is less than 16%.

[0071] Furthermore, the mean daylight deviation changes by less than 6% across the entire measured distance range, and specifically by less than 4%.

[0072] As already mentioned, in Fig. Figure 9 shows the mean value of a spectral stability factor relative to the beam center 12. The spectral stability factor is determined analogously to the mean daylight deviation, but instead of the difference with the normalized daylight spectrum, it is calculated using the normalized light spectrum at the beam center 12. Consequently, the mean value of the spectral stability factor at the center 12 (distance rM = 0 cm) is zero.

[0073] The mean value of the spectral stability factor, based on the beam center 12, is stable up to a distance r. M from about 20 cm less than 8%, up to my distance rM of about 14 cm less than 6%.

[0074] All in all, the diagrams show Fig. 8 and Fig. 9 the high degree and the special character of the beam homogeneity of the light beam produced by the hand lamp 1 6.

[0075] To generate the homogeneous light beam 6, the luminaire 7 comprises several light-emitting diodes (LEDs) as light sources, each emitting light with the same light spectrum. These can be, for example, COB LEDs. However, other designs are also conceivable. Preferably, the LEDs have a color-emitting material, e.g., a phosphor-based color-emitting material.

[0076] In Fig.Figure 10 shows a front view of the head 2 of the hand lamp 1. The front face of the lamp body 7 with the LEDs 24, each equipped with a lens, is clearly visible. The LEDs 24 are arranged in a plane. Nine LEDs 24 are evenly spaced on an outer circular path 25. Three LEDs 24 are evenly spaced on an inner circular path 26. This arrangement of the LEDs 24 results in a uniform intensity distribution of the generated light beam 6.

[0077] For example, instead of individual lenses for each LED, a single lens can be used for all LEDs. It is also conceivable to use a combination of individual lenses and a single lens for multiple LEDs.

[0078] It is understood that the figures merely illustrate a preferred embodiment of the invention. Other designs, particularly of the luminaire 7, which meet the requirements for the light properties according to the invention, are conceivable and will become apparent to those skilled in the art upon reading the foregoing explanations.

[0079] For example, a light source can be provided which, in addition to a cover plate, has one or more further optical elements (color filters, apertures, lenses) that are preferably interchangeable. The optical effects can also be achieved by a cover plate that also serves to protect the inside of the head.

[0080] In an application not shown, the handheld light can also be used as a stationary lighting device. For example, the handheld light can be mounted on a stand, a bracket on the ceiling or wall of the paint booth, a tripod, a handling device (robot), or a similar mounting system. Instead of being powered by a battery, the handheld light can also be connected to the mains power supply using an adapter, which is connected to the handheld light in place of the battery.

[0081] In general, the handheld light can also be connected to a control system, either wired or wirelessly (e.g., via Bluetooth). Using the control system, the handheld light can be switched on and off, or the light intensity can be adjusted. In this case, the on / off switch and the light intensity adjustment can be operated remotely using suitable devices. The on / off switch can also remain in the set position (on or off), while the light intensity can be remotely controlled or adjusted from 0% to 100%.

[0082] Sensors (e.g., color, surface, or distance sensors) may also be present. The settings of the handheld light are adjusted or regulated based on the sensor data (e.g., light intensity depending on distance).

[0083] A separate control system can also provide suggestions, for example, regarding the use of color filters or other optical elements, light intensity, etc., with which the handheld light should be equipped or adjusted to achieve optimal inspection results. This suggestion can also be based on sensor data, such as color, gloss level, distance, or surface roughness detection of the painted surface.

Claims

[1] Daylight hand lamp (1) for inspecting painted surfaces, in particular in the area of ​​paint repair work on motor vehicles, wherein the daylight hand lamp (1) has a light source (7) by means of which a light beam (6) can be generated, wherein the light beam (6) forms a beam cross-sectional area (11) at a distance of 30 cm ± 0.5 cm from the light source (7) along a beam axis (10) which is perpendicular to the beam axis (10), wherein the beam cross-sectional area (11) has at least a central core area (13) with an inner diameter of at least 16 cm, wherein at least in the core area (13) the light has a general color rendering index (CRi) with a value greater than 95, wherein the illuminance in the entire core area (13) is greater than 5000 Ix, wherein the beam cross-sectional area (11) additionally has an inner edge area (14) which surrounds the core area (13). surroundswherein the illuminance in the inner edge region (14) decreases to at least 1000 Ix, and wherein the light spectrum is at least homogeneous across the beam cross-sectional area (11), that in a spectral range with a wavelength of 400 to 700 nm, the mean daylight deviation is less than 20% at least in the core and inner edge region (13, 14) and / or that in a spectral range with a wavelength of 400 to 700 nm the mean value of a spectral stability factor with reference to the beam center is less than 10% at least in the core and inner edge region (13, 14). [2] Daylight hand lamp (1) according to claim 1, characterized by, that the calculation of the mean daylight deviation of a point on the beam cross-sectional area (11) is carried out in such a way that a light spectrum normalized to the maximum intensity is determined at the point, the difference of the determined light spectrum to a daylight spectrum normalized to the maximum intensity is formed, and then the mean of the difference amounts is formed over the spectral range from 400 to 700 nm. [3] Daylight hand lamp (1) according to claim 1 or 2, characterized by, that the calculation of the mean value of the spectral stability value with reference to the beam center (12) of a point on the beam cross-sectional area (11) is carried out in such a way that a light spectrum normalized to the maximum intensity is determined at the point, the difference of the determined light spectrum to a light spectrum normalized to the maximum intensity that was determined at the beam center (12) is formed, and then the mean value of the difference amounts is formed over the spectral range from 400 to 700 nm. [4] Daylight hand lamp (1) according to any one of the preceding claims, characterized by , that the core area (13) has an inner diameter of at least 20 cm, preferably 24 cm. [5] Daylight hand lamp (1) according to any one of the preceding claims, characterized by that the illuminance in the core area is greater than 6000 Ix, preferably greater than 7000 Ix, or even more preferably greater than 8000 Ix. [6] Daylight hand lamp (1) according to any one of the preceding claims, characterized by , that the mean daylight deviation in the core and inner edge area (13, 14) is less than 18%, in particular less than 16%. [7] Daylight hand lamp (1) according to any one of the preceding claims, characterized by that the mean daylight deviation in the core area and inner edge area (13, 14) changes by less than 6%, preferably by less than 4%. [8] Daylight hand lamp (1) according to any one of the preceding claims, characterized by , that the mean value of the spectral stability factor with reference to the beam center (12) in the core and inner edge region (13, 14) is less than 8%, in particular less than 6%. [9] Daylight hand lamp (1) according to any one of the preceding claims, characterized by , that the illuminance in the inner edge region (14) decreases to 500 Ix, preferably to 300 Ix. [10] Daylight hand lamp (1) according to any one of the preceding claims, characterized by, that the inner boundary region (14) is ring-shaped. [11] Daylight hand lamp (1) according to any one of the preceding claims, characterized by , that the inner edge region (14) has a width greater than 4 cm, preferably greater than 6 cm, or even more preferably greater than 8 cm. [12] Daylight hand lamp (1) according to any one of the preceding claims, characterized by , that the color temperature is greater than 5500 K and / or less than 6500 K, at least in the core and inner edge area (13, 14). [13] Daylight hand lamp according to one of the preceding claims, characterized by that the light fixture has at least one halogen lamp as its light source, [14] Daylight hand lamp (1) according to any one of the preceding claims, characterized by , that the light source (7) comprises one or more light-emitting diodes (24). [15] Daylight hand lamp (1) according to any one of the preceding claims, characterized by, that the luminaire (7) comprises several light-emitting diodes (24) as a light source, wherein the respective light-emitting diodes (24) emit light with the same light spectrum. [16] Daylight hand lamp according to one of the preceding claims, characterized by that the light source comprises one or more COB light-emitting diodes. [17] Daylight hand lamp (1) according to any one of the preceding claims, characterized by , that the luminaire (7) comprises as a light source one or more light-emitting diodes (24) which have a color-giving luminescent material, preferably a phosphor-based color-giving luminescent material. [18] Daylight hand lamp according to one of the preceding claims, characterized by that the luminaire comprises several light-emitting diodes as a light source, wherein at least one light-emitting diode is provided to form the light spectrum, which emits light with a light spectrum that differs from the light spectrum of another light-emitting diode. [19] Daylight hand lamp (1) according to any of the preceding claims, characterized by , that the luminaire (7) comprises several light-emitting diodes (24) as a light source, wherein the light-emitting diodes (24) are each provided with a lens. [20] Daylight hand lamp (1) according to one of the preceding claims, characterized by , that the light source (7) comprises several light-emitting diodes (24) as a light source, wherein all light-emitting diodes (24) are arranged in one plane, wherein several, in particular nine, light-emitting diodes (24) are arranged equally distributed on an outer circular path (25) and several, in particular three, light-emitting diodes (24) are arranged equally distributed on an inner circular path (26). [21] Daylight hand lamp according to one of the preceding claims, characterized by , that the daylight hand lamp (1) is designed as a cordless, accumulator (4) powered hand lamp (1). [22] Daylight hand lamp (1) according to any one of the preceding claims, characterized by, that the luminous intensity of the light beam (6) produced by the light source (7) is adjustable.

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