Lighting device and method with automatic shadow formation compensation

Abstract

To provide an illumination device and an illumination method capable of illuminating a surface.SOLUTION: A control unit (10) captures an illuminance specification and controls light sources (a.1, b.1, c.1) of an illumination device in such a way that the maximum illuminance achieved on the surface is equal to the illuminance specification. Each light source (a.1, b.1, c.1) can be controlled independently of any other light sources. Several distance meters (dm.2,..., dm.6) measure the respective distance between themselves and the illuminated surface. The control unit (10) detects the event that an object (AO) is shading an area of the surface and causes this shading to be at least partially compensated. For this purpose, the control unit (10) increases the maximum illuminance of unshaded light sources (a.1, b.1, c.1). Preferably, the maximum illuminance of light sources that are redundant or partially redundant to shaded light sources and are not themselves shaded is increased.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to a lighting device and a lighting method with automatic compensation for brightness changes caused by shadow formation. Shadow formation is caused by objects located in the space between the lighting device and the surface being illuminated by the lighting device. [Background technology]

[0002] Such lighting devices are used, for example, to illuminate an operating table and, therefore, a patient on the operating table. Objects, such as body parts of a person treating the patient or instruments used, can get between the lighting device and the patient on the operating table, thereby casting a shadow on the illuminated patient. If shadow formation is not detected, or if it is detected but not adequately compensated for, this can result in the patient area not being illuminated brightly enough.

[0003] Typically, lighting devices include multiple light sources that are directed toward the operating table. Therefore, objects between the lighting device and the operating table usually do not cast perfect shadows ("drop shadows"), but simply result in less illumination of individual areas of the illuminated surface, i.e., the patient, than desired. This should also be understood as being included in the term "shadow formation." Summary of the Invention [Problem to be solved by the invention]

[0004] The problem on which the invention is based is to provide an illumination device and an illumination method which can automatically compensate for shadows cast by human body parts and / or by objects better than known illumination devices and illumination methods. [Means for solving the problem]

[0005] The above-mentioned problem is solved by a lighting device having the features of claim 1 and a lighting method having the features of claim 14. Advantageous configurations are set out in the dependent claims. Advantageous configurations of the lighting device according to the invention are also advantageous configurations of the lighting method according to the invention, as far as this is reasonable, and vice versa.

[0006] The lighting device according to the invention and the lighting method according to the invention make it possible to illuminate a surface, which is for example an operating table or also a patient on an operating table.

[0007] In the following, we first define some terms that relate to lighting devices and that will be used hereinafter to describe the present invention.

[0008] The lighting device according to the invention, as well as many lighting devices known from the prior art for medical purposes, comprise a plurality of individual light sources. In the following, the term "lighting unit" will be used. This term is a generic term for the lighting device as a whole and for each individual light source and group of light sources.

[0009] The "Illuminance" (Ev) of a lighting unit is the luminous flux per unit area that starts from the lighting unit and strikes a surface. The SI unit is Lux = Lumen / m 2 In a plane perpendicular to the central optical axis of the lighting unit, the illuminance of the lighting unit typically reaches a maximum at the intersection of the central optical axis with this plane. In particular, if the lighting unit comprises several individual light sources, the maximum illuminance value may be assumed outside the intersection, for example on a circle centered on the intersection. The maximum illuminance is usually related to the distance between the lighting unit and the object to be illuminated, and is therefore often related to a predetermined reference distance. In medical applications, the reference distance is often 1 m.

[0010] For the sake of distinction, the term "total irradiance" is used for the irradiance achieved by the lighting device as a whole, and the term "individual irradiance" for the irradiance generated by an individual light source. Correspondingly, the terms "maximum overall irradiance" of a lighting device and "maximum individual irradiance" of an individual light source are used. (Local) irradiance and maximum irradiance are variable quantities that each take on a single value at a given time. In contrast, the maximum possible individual irradiance of a light source is a value that is predetermined by the light source's structure and only gradually decreases over time due to aging, if any. The maximum individual irradiance lies between zero and the maximum possible individual irradiance (which is also inclusive).

[0011] The lighting unit has a central optical axis and generates a light field on the illuminated surface. This light field has an illuminance that varies across the illuminated surface and has a maximum value at one point or one area of ​​the surface. This area is hereinafter referred to as the "maximum area." The maximum area may be a discrete point or, idealized, may be a ring, preferably having as its center the intersection of the optical axis and the illuminated surface.

[0012] The light field of a lighting unit can be described by a three-dimensional representation, where the illuminated surface, assumed to be planar, extends in the xy plane of this representation, and the illuminance achieved by the lighting unit at a point (x, y) on the surface is plotted on the z axis. In many cases, the light field of a lighting unit is idealized to have the shape of a bell curve, which reaches its maximum at the intersection of the optical central axis and the illuminated surface.

[0013] If the illuminated surface is flat and perpendicular to the central optical axis of the lighting unit, the area of ​​the surface where the averaged illuminance is x% of the maximum illuminance is typically a circle. The average illuminance in this area with x% illuminance is preferably the average value of the illuminances at several points on this circle, in particular at least four points evenly distributed on this circle. The standard IEC 60601-2-41 for surgical lighting equipment specifies as many as eight evenly distributed points on the circle. The diameter of this circle is often referred to as the light field diameter d x The light field diameter d is also referred to as the distance between the lighting unit and the surface being illuminated. x is often related to a predetermined reference distance between the lighting unit and the surface being illuminated, for example a reference distance of 1 m. For medical lighting units, often x=10%, often x=50%, the light field diameter is the diameter at which the illuminance is one tenth or half of the maximum illuminance at the surface Ob. For lighting units for operating tables, d 10 is typically 13cm to 35cm. In many configurations, the user 10 A desired value for can be predetermined.

[0014] Light field diameter d x The circle defined immediately above, with x It is also called "yen". x The center point of the circle is the intersection of the optical central axis and the illuminated surface. x The area on the surface that is enclosed by a circle and has the shape of a perfect circle will be referred to hereafter as "d x It is called the "area."

[0015] The lighting device according to the invention and the lighting method according to the invention make it possible to illuminate surfaces, such as surfaces of a medical operating table and of a patient on the operating table, facing the lighting device. The lighting method according to the invention is carried out using the lighting device according to the invention.

[0016] The lighting device according to the invention has a central optical axis and includes a light source set with a plurality of light sources. Preferably, the light source set includes at least 10 light sources, particularly preferably at least 30 light sources, in particular at least 60 light sources. The lighting device may include at least one further light source, which does not belong to the light source set and therefore does not necessarily have all the properties that a light source of the light source set has according to the invention or preferably has, as described below.

[0017] The light sources of a light source set can be externally controlled and may all have the same structure, or at least two of the light sources of a light source set may be different from each other.

[0018] Each light source of the light source set has an optical axis. The optical axes of two different light sources do not coincide with each other because the two light sources are spaced apart from each other. Each light source can generate a light field on the illuminated surface. Preferably, the light field of a light source is rotationally symmetrical with respect to the optical axis of the light source. The characteristic predetermined by the structure of the light source is the maximum possible individual irradiance of the generated light field, which is preferably related to the reference distance. All light sources of the light source set may have the same maximum possible individual irradiance. At least two light sources of the light source set may differ from each other in terms of their maximum possible individual irradiance.

[0019] At each point in time, the maximum individual irradiance of a light source takes a value between zero and the maximum possible individual irradiance of this light source (inclusive). The current value of the maximum individual irradiance of a light source of a light source set is defined and changed by an external driving control, in particular independently of the other light sources of the light source set and thus independently of the respective current values ​​of the maximum individual irradiance of the other light sources.

[0020] As already mentioned above, the lighting device achieves its maximum overall illuminance at its maximum area. In many cases, the maximum area is rotationally symmetrical with respect to the intersection of the lighting device's central optical axis and the illuminated surface. If the lighting device is moved laterally or tilted relative to the illuminated surface, the maximum area generally moves across the illuminated surface. What maximum overall illuminance the lighting device achieves at the surface and where the maximum area is located relative to the central optical axis is related, on the one hand, to the respective maximum individual illuminance of each light source and, on the other hand, to the respective orientation of the optical axis of the light source relative to the central optical axis.

[0021] The lighting device further includes a distance measurement assembly. The distance measurement assembly includes a plurality of distance measuring devices, i.e., at least two distance measuring devices, which are spaced apart from one another. Each distance measuring device of the distance measurement assembly has a measurement direction facing the illuminated surface. Each distance measuring device can measure a measure of the distance between itself and a light-scattering object in the measurement direction. The light-scattering object may be the illuminated surface or an object on the surface, or it may be a shadow-forming object, i.e., an object that penetrates into the area between the lighting device and the illuminated surface and has a distance to the illuminated surface.

[0022] The lighting device further includes a control unit for processing the signals. The control unit may be integrated into the light source support of the lighting device or may be spatially separated from such support. A data connection from the control unit to each light source of the light source set is formed between the control unit and the light source, either permanently or at least temporarily, and this data connection may be realized by cable and / or electromagnetic radio waves. A further data connection runs permanently or at least temporarily from the distance measurement assembly to the control unit.

[0023] The control device can receive and automatically process signals and settings of the distance measuring assembly. Such settings can come from a user or from a higher-level open-loop or closed-loop control. According to the present invention, the control device can detect an illuminance setting as a setting. This illuminance setting predefines a target value for maximum overall illuminance, and the lighting device should achieve a maximum overall illuminance having this value. Preferably, the illuminance setting is related to a reference distance.

[0024] In connection with this process, the control device can activate and control the light sources of the light source set, and in particular can activate and control each light source independently of each of the other light sources. Furthermore, the control device can detect predetermined information for each light source of the light source set. This information can be stored in a data memory to which the control device has at least temporary read access. This information can also be predetermined as parameters of a stored program, which the control device executes when illuminating the surface. Typically, this program is stored in the data memory of the control device and executed on a processor of the control device. One part of the information can be stored in the data memory, and another part can be predetermined as parameters of the program.

[0025] The information about the light sources of the light source set includes, on the one hand, a measure of the maximum individual irradiance that this light source can generate, i.e., a measure of the maximum possible individual irradiance that is predetermined by the design. Preferably, this maximum possible individual irradiance is related to the above-mentioned reference interval. This measure is, for example, the maximum voltage that can be applied to the light source, or the maximum current intensity or maximum power for the light source.

[0026] The information about each light source of the light source set, on the other hand, includes information about how the optical axis of this light source is positioned and oriented relative to the optical central axis of the lighting device. The optical axis of the light source may coincide with the optical central axis of the lighting device, may be parallel to the optical central axis but at a certain distance from it, may intersect with it, or may be tilted relative to it. Two lines in space are tilted relative to each other if they do not coincide with each other, are not parallel to each other, and do not intersect. The information detected by the control device particularly defines how the optical axes of the light sources are positioned relative to each other.

[0027] The control device can drive and control each light source of the light source set individually, i.e. independently of each of the other light sources of the light source set. By means of a corresponding drive control, the control device can adjust each maximum individual illuminance of a light source to a value lying between zero and the maximum possible individual illuminance of this light source (inclusive). In one implementation, the control device can vary the achieved maximum illuminance steplessly, while in another implementation it can vary it stepwise. Thanks to this drive control, each maximum individual illuminance of a light source of the light source set is varied independently of each of the other light sources. Note: Naturally, as a rule, the maximum individual illuminance of a light source is not defined exactly to the desired value, but only with a certain error.

[0028] Note: At least two individual light sources of a lighting device may be combined into one light source module, and these individual light sources of one light source module may only be driven and controlled together. In this case, the term "light source of a light source set" is understood to mean such a light source module comprising at least two individual light sources. A lighting device according to the invention in this case comprises at least two such light source modules. A light source module is, for example, a group comprising at least two individual light sources, which group can be replaced separately from the rest of the lighting device.

[0029] According to the present invention, the control device can receive and process signals from the distance measurement assembly. This processing allows the control device to automatically check whether a shadow formation event has occurred and / or whether a shadow formation event is currently present, and in particular to detect a shadow formation event. A "shadow formation event" is understood to mean the following event: at least one object is currently located between the lighting device and the illuminated surface, or more precisely, between at least one light source of the light source set and the illuminated surface. By processing the signals from the distance measurement assembly, the control device can detect a shadow-forming object, at least if it alters the respective distances measured by this or at least one distance measurer of the distance measurement assembly. Generally, this object completely or at least partially shadows at least one light source of the light source set, altering at least one measured distance. Therefore, the term "shadow-forming object" is also used hereinafter. This term can also refer to multiple objects, such as the body parts of a doctor performing treatment and the instruments used by the doctor. Generally, the position of the shadow-casting object changes relative to the lighting device, and therefore the shadow cast changes over time.

[0030] If no countermeasures are taken, shadow formation by a shadow-forming object will change the light field that the lighting device achieves on the illuminated surface. "Shadow formation compensation" is understood to mean measures that the control device automatically triggers in order to at least partially compensate for shadow formation. Ideally, the light field that the lighting device achieves on the illuminated surface will remain unchanged thanks to shadow formation compensation. In practice, this goal is often only approximately achieved.

[0031] According to the present invention, this objective is achieved as follows: The main objective of shadow compensation is that both the maximum overall illuminance achieved by the lighting device and the position of the maximum area relative to the central optical axis of the lighting device remain unchanged, so that despite shadow formation, the maximum overall illuminance achieved is equal to the illuminance setting. The maximum area should maintain its position relative to the central optical axis. In other words, the position of the maximum area relative to the central optical axis should not be changed by shadow formation events. In the case of medical lighting devices, this maximum area is often surrounded by the area of ​​the patient's body where surgery is performed.

[0032] An optional further objective is that the overall light field diameter achieved by the illumination device additionally remains unchanged. x It may also be that the circle should not change its position relative to the optical center axis. An optional third objective is that the relative overall color temperature of the lighting device also remains unchanged. Depending on the degree of shadow formation, these objectives may be fully or only partially achieved. It is possible for the control device to attempt to automatically achieve these three objectives in descending priority. It is also possible for the control device to make a compromise between at least two of these objectives.

[0033] Simply put, the or each measure for shadow compensation involves increasing the maximum individual illuminance of at least one light source where no shadows are formed. While it is possible in principle to vary the light field diameter and / or correlated color temperature of individual light sources, this is not required by the present invention. It is also generally not required by the present invention that actuators be able to move light sources relative to the support of the lighting device, and thus relative to other light sources. Rather, all light sources may be fixedly mounted within the support and only move together with the support. Eliminating actuators saves space within the support and eliminates the need for actuator control.

[0034] The control device is further configured as follows: if a shadow-forming event, i.e., a shadow-forming object, is detected, the control device determines, at least approximately, an area on the illuminated surface that is completely or at least partially shadowed by an object between the lighting device and the illuminated surface. Generally, shadow-forming objects do not form drop shadows, since lighting devices include multiple light sources. "At least partially shadowed" means that in this area, the illuminance after shadow formation deviates downward from the illuminance before shadow formation by more than a predetermined limit. For example, the illuminance may decrease by at least 30%, or even by at least 50%, due to shadow formation.

[0035] To determine the shadowed area, the control device uses predetermined, detected information for each light source, such as how the optical axis of the light source is oriented and / or positioned relative to the central optical axis of the lighting device. Additionally, the control device uses signals from a distance measurement assembly. Preferably, the control device uses two simplifying assumptions when determining the area: the assumption that the illuminated surface is perpendicular to the central optical axis of the lighting device, and the assumption that the distance to the lighting device is equal to the reference distance. In many cases, the deviation between reality and these two assumptions is insignificant in practice.

[0036] Preferably, the control device determines a contour of the shadow-forming object in a plane perpendicular to the central optical axis of the lighting device. To determine the shadow-forming region, the control device uses the determined contour and the distance along the central optical axis between the lighting device and the illuminated surface, as well as the distance between the lighting device and the shadow-forming object and / or the distance between the shadow-forming object and the illuminated surface.

[0037] The control device searches for at least one light source of the light source set that is suitable for shadow formation compensation, or more precisely: at least one light source of the light source set that is currently suitable for at least partially compensating the detected shadow formation, generally together with at least one other light source of the light source set. For this search, the control device uses information about the determined shadow formation area of ​​the illuminated surface. Preferably, the control device searches for at least one light source of the light source set that has the following property: each optical axis of the or each determined light source intersects the surface in the shadow formation area.

[0038] According to the invention, a light source is suitable for shadow formation compensation if the following conditions occur cumulatively, and whether these conditions are met is checked automatically: The light source is not currently casting any shadows, or at least not completely. The optical axis of the light source intersects the illuminated surface in the determined shadow-forming area. The light source is currently operating with respect to its maximum individual irradiance, which is lower than the maximum possible individual irradiance of this light source. The light source may currently be switched off. The current value of the maximum individual irradiance of this light source can therefore be increased.

[0039] Further, above, an arrangement was described in which the control device determines the contour of the shadow-forming object in a plane perpendicular to the central optical axis. In one arrangement, if the optical axis of the light source does not extend through the determined contour and is spaced apart from this contour, then the light source is not shadowed, or at least not completely shadowed.

[0040] The control device uses the signal of the distance measurement assembly and the above-described detected information about the light sources to search for such suitable light sources. Generally, which light sources are currently casting shadows and which are not casting shadows are related to at least one dimension of the shadow-casting object and the position of the object relative to the lighting device and / or the illuminated surface. In particular, which light sources are suitable and which are not related to the outline of the shadow-casting object and the distance between the shadow-casting object and the illuminated surface in a plane perpendicular to the optical central axis.

[0041] The control device may not find a suitable light source, especially if all unshadowed light sources are already operating at their maximum possible individual illuminance.

[0042] The control device is further configured as follows: if the control device finds at least one suitable light source, the control device determines a subset of the light source set, which subset includes at least one light source and consists of only light sources that are currently suitable for shadow formation compensation. The subset may consist of all currently suitable light sources or a subset of suitable light sources. The subset may consist of only one suitable light source, even if there are multiple suitable light sources. Advantageous configurations provide for various implementations of how this subset can be determined.

[0043] The control device can cause an increase in the respective maximum individual irradiance of the or each light source of the determined subset. For this purpose, the control device can calculate or otherwise determine a target value for each light source of the determined subset. This target value defines the maximum individual irradiance to be achieved for this light source. The calculated target value for a suitable light source is greater than the current value of the maximum individual irradiance and, in one configuration, is equal to a predetermined maximum possible individual irradiance of this light source, while in another configuration it is less than the maximum possible individual irradiance. The control device determines the maximum possible individual irradiance from the above-mentioned information about the light sources.

[0044] To determine the subset and calculate respective target values ​​for maximum individual illuminance, the control device uses the detected information about the light sources of the light source set and, optionally, signals of the distance measurement assembly. The control device performs the calculation of target values ​​for the light sources of the subset with the objective that the actual value of the maximum overall illuminance currently achieved by the lighting device is equal to the detected illuminance setting.

[0045] The control device controls the or each light source of the determined subset with the objective that the actual value of the maximum individual illuminance currently achieved by the light source is equal to the calculated target value.

[0046] That is, the objective is to drive and control the light sources of the determined subset so that the determined subset can completely or at least partially compensate for shadow formation. According to the invention, the control device increases the value of the maximum individual irradiance of at least one light source of the determined subset, preferably of each light source. Of course, it may be that shadow formation can only be partially compensated for, even though at least one suitable light source has been found. Two possible reasons for this are that not enough suitable light sources have been found, or that the further achievable increase in the maximum individual irradiance of the found suitable light sources is insufficient.

[0047] The method according to the invention is carried out using the lighting device according to the invention and comprises the following steps: The control device detects predetermined information about each light source of the light source set. The control device detects the light setting. The control device adjusts the current maximum individual illuminance of each light source of the light source set to a certain value, in particular at least once and, if necessary, renewed. · The lighting device illuminates the surface to achieve maximum overall illumination. The or each distance measuring device of the distance measuring assembly measures a measure for each distance between itself and the light scattering object. The distance measuring device measures this measure at least once, preferably multiple times, particularly preferably at a fixed sampling frequency. The control device checks whether a shadow formation event has occurred. For this check, the control device uses the signal of the distance measuring assembly. The control device performs this check at least once, preferably repeatedly, particularly preferably at a fixed sampling frequency. The sampling frequency of the control device may be equal to the sampling frequency of the distance measuring assembly, or may be smaller or larger than the sampling frequency of the distance measuring assembly.

[0048] The detection of a shadow formation event triggers at least the following further steps:

[0049] The control device searches for at least one light source of the light source set that is currently suitable for shadow formation compensation.

[0050] If at least one light source suitable for shadow formation compensation is found, the control device executes the following steps: The control device determines a subset comprising at least one suitable light source. The subset may consist of all suitable light sources. For each light source of the selected subset, the control device calculates a target value, which determines what maximum individual irradiance this light source should produce. The calculated target value is greater than the current value of the maximum individual irradiance and less than or equal to the maximum possible individual irradiance. The control device controls this or each light source of the determined subset, preferably each light source, so that the controlled light source actually achieves the calculated target value for the maximum individual illuminance. The control device performs a calculation of target values ​​for the subset of light sources with the objective that the maximum area maintains its position relative to the optical center axis and the overall irradiance takes a value equal to the detected irradiance setting.

[0051] According to the present invention, in many cases, shadow formation can be compensated for relatively well. In particular, in many cases, the maximum overall illuminance is reduced relatively little, so that the surface is still sufficiently illuminated despite shadow formation. In particular, the maximum area often remains sufficiently strongly illuminated. Moreover, this often results in the light field achieved by the lighting device on the illuminated surface changing relatively little, thanks to the compensation according to the present invention, despite shadow formation.

[0052] The present invention does not require that the lighting device include an actuator that can pivot or otherwise move at least one light source relative to at least one other light source.

[0053] The present invention applies to lighting devices in which light sources emit different light, for example, light having different correlated color temperatures and / or different amplitudes, and shadow formation is detected based on these differences. However, the present invention does not require lighting devices to have such light sources. All light sources in a lighting device may emit light having the same amplitude.

[0054] According to the present invention, the control device determines the shadow-forming region, i.e., determines which regions of the illuminated surface are shadowed by objects. To at least approximately compensate for this shadow-forming, the control device determines at least one light source whose optical axis intersects the illuminated surface in the shadow-forming region. The maximum individual illuminance of such light source is increased. This feature allows shadow-forming to be compensated for better than known methods in many cases. This effect is achieved, in particular, because the shadow-forming region on the surface is determined, but not the size of the shadow-forming object, or not only the size of the shadow-forming object. In particular, shadow-forming is often compensated for relatively well even when all light sources are not arranged concentrically around the optical center axis. Furthermore, the present invention provides a better estimation than simply determining which light sources are not currently casting shadows. That is, a light source may indeed not be casting a shadow, but its optical axis may intersect the illuminated surface outside the shadow-forming region. In many cases, it is not reasonable to increase the maximum individual illuminance of this light source.

[0055] Preferably, the control device additionally detects information about the position of each measurement direction of each distance measuring device relative to the optical central axis of the lighting device. Preferably, the control device can automatically determine whether a light source of the light source set is currently being shadowed, and if so, which light source of the light source set is currently being shadowed. In a preferred configuration, the control device detects shadowing of a light source if it is detected that a light-scattering object is located within the section of the light source's optical axis that leads from the light source to the illuminated surface. In one configuration, the control device can determine which distance measuring device of the distance measuring assembly has detected a distance that is significantly shorter than the distance between the distance measuring device and the illuminated surface, for example, a distance that is outside a predetermined tolerance band. Of course, there may be only such distance measuring devices present.

[0056] Preferably, the control device can repeatedly, particularly preferably at a predetermined sampling frequency, check whether a shadow formation event is currently present. The control device is preferably configured to perform the measures for shadow formation compensation described immediately above at such sampling frequency. By repeatedly performing these measures, in many cases, shadow formation can be quickly detected and at least partially compensated for. The sampling frequency is generally limited by the sampling frequency that the distance measurement assembly can achieve and / or the computing capacity of the control device. In many cases, the time required to change the maximum individual irradiance of the light source can also be a limiting factor.

[0057] According to the present invention, the control device can detect the illumination setting. In one configuration, the control device can additionally detect the light field diameter setting. This light field diameter setting can also come from the user or from a higher-level open-loop or closed-loop control. The light field diameter setting predefines a target value for the overall light field diameter. This is the light field diameter that the light field generated by the entire lighting device should have. This overall light field diameter is also preferably related to the reference distance mentioned above and is related to the illuminated surface perpendicular to the optical central axis of the lighting device.

[0058] According to the present invention, the control device determines a subset of suitable light sources and calculates a target value for the maximum individual illuminance for each light source of the determined subset. According to the present invention, the goal when calculating the target value is for the overall illuminance to match the illuminance setting. In the configuration described above, a further (additional) goal when calculating the target value is for the overall light field diameter value to match the light field diameter setting. This configuration, in other words, allows for better compensation for shadow formation. In many cases, it is achieved that the light field achieved by the lighting device after compensation for shadow formation on the illuminated surface deviates relatively little from the light field achieved by the lighting device before shadow formation, ideally not in a way that is perceptible to humans. In many cases, the overall light field diameter also changes relatively little despite shadow formation, because the shadow formation compensation configuration described immediately above is applied. Of course, the optional further goal may not be fully achieved.

[0059] The configuration described further above using the total light field diameter can be combined with the configuration already described in which a light source that is completely or at least partially shadowed is switched off.

[0060] According to the present invention, the control device detects the illuminance setting and optionally the light field diameter setting. The control device detects shadow formation events. In one configuration, the control device detects the maximum area and / or d x Check whether the area is located within the shadow forming area. The maximum area is also within the circle. x If the region is also not located within a shadow-forming region, then in many cases it is not necessary to compensate for the shadow-forming event.

[0061] The control device is preferably configured to calculate and predict the overall light field diameter at least once. The generated overall light field, and thus the overall light field diameter, is related, on the one hand, to the current value of the maximum individual irradiance of each light source that is not switched off, and, on the other hand, to the position of the optical axis of the light source relative to the optical central axis of the lighting device. Preferably, the control device uses predetermined standard values ​​for each individual light field diameter of the light source. Preferably, the overall light field diameter is again related to a reference interval and a surface perpendicular to the optical central axis at the reference interval. The control device calculates a target value for the maximum individual irradiance so that the predicted overall light field diameter is as close as possible to the light field diameter setting, and does not deviate, for example, by more than a predetermined tolerance.

[0062] According to the present invention, the control device searches for at least one light source that is currently suitable for shadow compensation. This search may also include partially shadowed, but not completely shadowed, light sources. In contrast, in one configuration, the control device is configured to search only for completely unshadowed light sources during this search. This means that partially shadowed light sources are not considered during the search. This configuration saves computation time and / or computing capacity in many cases.

[0063] Preferably, the control device switches off all light sources that are completely or at least partially shadowed. This configuration reduces energy consumption in many cases. Furthermore, in many cases, when a completely or at least partially shadowed light source is switched off, heating of the shadowed object is reduced. Such heating is often undesirable, especially when the shadowed object is a body part of the treating physician. Shadowed objects are closer to the lighting device than the illuminated surface and are therefore often exposed to a stronger thermal energy input per unit area. Preferably, the control device checks at least once, preferably repeatedly, whether the light source is still shadowed. If the light source is no longer switched off, it can be switched on again.

[0064] Generally, each light source has a correlated color temperature. Typically, this correlated color temperature is predetermined by the structure of the light source and does not change. All light sources in a light source set may have the same correlated color temperature. In contrast, in a preferred configuration, the light sources in a light source set collectively have at least two different correlated color temperatures. That is, a first subset of light sources has a first correlated color temperature, and a second subset of light sources has a second correlated color temperature that is different from the first correlated color temperature. For example, the light sources in the first subset are warm white, and the light sources in the second subset are cool white. In one implementation, the light sources in the first subset have a color temperature of 2700 Kelvin (warm white), and the light sources in the second subset have a color temperature of 6500 Kelvin (cool white). More than two different correlated color temperatures are also possible.

[0065] The illumination achieved by the lighting device as a whole has a correlated overall color temperature that is additionally composed of the correlated color temperatures of the light sources that are currently switched on and not completely shaded, and that is generally additionally related to the maximum individual illuminance of each of these light sources.

[0066] In one configuration, the control device can detect a color temperature setting. This setting can again come from a user or from a higher-level open-loop or closed-loop control. As explained immediately above, the control device calculates a maximum individual illuminance for each light source of the light source set. This maximum individual illuminance is related to the illuminance setting, optionally the light field diameter setting, and additionally an optional color temperature setting. Generally, the control device can change the value of each maximum individual illuminance of the light sources by driving control, in particular between zero and each possible maximum individual illuminance, while each light field diameter and each correlated color temperature of each light source are preferably constant and cannot be changed.

[0067] As soon as the control device detects a shadow formation event, the control device, according to the present invention, determines a subset of light sources suitable for shadow formation compensation and calculates or determines a target value for the maximum individual illuminance for each light source of the determined subset. This is, of course, only performed if at least one suitable light source has been found. The primary goal when calculating these target values ​​is that the deviation between the illuminance setting and the achieved or expected value of the maximum overall illuminance is as small as possible. Optional further goals are, in particular, that the achieved overall light field diameter deviates as little as possible from the detected light field diameter setting, and that the achieved and corrected overall color temperature deviates as little as possible from the detected color temperature setting, preferably in this order.

[0068] According to the invention, the control device is capable of detecting an illuminance setting and, optionally, additionally, a light field diameter setting and / or a color temperature setting. Preferably, the control device is configured as follows: if the control device detects a setting, it calculates an initial target value for each light source of the light source set. The initial target values ​​define the maximum individual illuminance that the light sources should generate. When calculating the initial target values, the aim is that the achieved overall illuminance is equal to the illuminance setting and, optionally, the achieved overall light field diameter is equal to the light field diameter setting.

[0069] In one implementation, the control device automatically evaluates a table ("look-up table") that predefines initial target values ​​to be adjusted, one for each light source of the light source set, for multiple possible illuminance settings and optionally multiple possible light field diameter settings and / or color temperature settings. The initial target values ​​are valid for no-shadow situations and remain valid, at least as long as the control device does not detect any deviating settings or shadow-forming events. Table-based configurations often require relatively little computational capacity and / or time.

[0070] The control device is further configured to: if a shadow formation event has been detected and a light source suitable for shadow formation compensation has been found, the control device executes at least one increase sequence, the or each increase sequence including the steps of: The control device determines a subset, which consists of at least one light source of the set of light sources that is currently suitable for shadow compensation. The criteria for a currently suitable light source to fulfill are described further above. For the or each light source of the determined subset, the control device calculates a respective target value. This target value defines the maximum individual illuminance that the light source should achieve. The aim when calculating the target value has been explained further above: the achieved overall illuminance should be equal to the detected illuminance setting. Generally, the illuminance setting does not change due to shadow-forming events. The or at least one target value may be the maximum possible individual illuminance of the light source. The control device drives the or each light source of the determined subset, thereby increasing the current maximum individual illuminance of each light source to the calculated target value.

[0071] In one development of this configuration, the control device is further configured as follows: Each increase sequence includes determining a subset and calculating, for each light source of the determined subset, a target value for its maximum individual irradiance. In this development, the control device performs a computational check to determine whether the currently achieved actual value of the maximum overall irradiance of the lighting device corresponds sufficiently accurately to the detected irradiance setting. For this computational check, the control device uses the respective values ​​of the maximum individual irradiance of each unshadowed light source of the light source set as well as the respective information about each unshadowed light source. The control device preferably performs a computational prediction before controlling the light sources that are actually suitable. In this prediction, the control device predicts what maximum overall irradiance the lighting device will achieve with this adjustment. If the maximum overall illuminance predicted by the calculation does not match the illuminance setting accurately enough, the control device checks whether at least one maximum individual illuminance can be increased or increased further. If at least one maximum individual illuminance can be increased or can be increased further, the control device preferably performs the step of determining a new subset and calculating one maximum individual illuminance for each light source of the determined subset in this new run. This determined subset may be the same as the previously determined subset or may be different from the previously determined subset. Alternatively, the control device determines that the deviation between the illuminance setting and the current maximum overall illuminance cannot be reduced any further and therefore does not execute further increase sequences.

[0072] Such a step-by-step approach requires less computation time in many cases than other possible approaches.

[0073] According to the invention, the control device is configured as follows: if the control device finds at least one light source that is suitable for shadow formation compensation, the control device determines a subset comprising at least one suitable light source, optionally comprising a plurality of suitable light sources.

[0074] Preferably, this process in which a shadow formation event is detected triggers the following steps: The control device detects at least one light source that is completely or at least partially shadowed, preferably each light source that is shadowed. The control device searches for a light source that satisfies a predetermined compensation criterion for this shadowed light source or at least one shadowed light source. If at least one such light source is found, the control device checks which of the found light sources is suitable for shadow formation compensation. If at least one light source that satisfies the compensation criteria and is suitable is found, the control device determines a set of such light sources that consists of the satisfying and suitable light sources as a subset, and uses this determined subset to at least partially compensate for the shadow formation.

[0075] Preferably, to check whether the light source satisfies the or each predetermined compensation criterion, the control device uses detectable information about the light source. This detectable information is predetermined and is not related to current operation or shadow formation. This information can therefore be quickly detected, for example, by read access to a data memory. Therefore, the control device preferably first searches for further light sources that satisfy the or each compensation criterion, and then checks whether these further light sources are also suitable for shadow formation compensation, individually or in combination.

[0076] The arrangement described further above, in which at least one boosting sequence is performed, may be combined with the arrangement described, in which at least one compensation criterion is used. Preferably, this combination comprises the following steps: A first increase sequence is performed, in which a search is made for light sources that satisfy the or each compensation criterion and are suitable for shadow formation compensation, and the subset used during the first increase sequence consists of such light sources that satisfy the or each compensation criterion and are suitable for shadow formation compensation. · Predict or check whether the first boost sequence is sufficient to compensate for shadow formation. If the first boost sequence is not sufficient to compensate for the shadow formation, a second boost sequence is performed, in which a light source that does not satisfy each compensation criterion, optionally not satisfying any of the compensation criteria, and that has not been used in the first boost sequence, and that is also suitable for shadow formation compensation, is searched for.

[0077] It is also possible to carry out more than two increase sequences, in which case after each increase sequence, optionally except after the last increase sequence, it is checked whether shadow formation is now sufficiently compensated, with weaker conditions being imposed in each increase sequence on the light source used than in the previous increase sequence.

[0078] In the following, a preferred configuration of how this subset is determined is described, which defines this or a compensation criterion, and particularly preferably, in which the light sources of the light source set do not have to change their position and orientation relative to the other light sources.

[0079] In this preferred configuration, the lighting device comprises at least one first light source and at least one further light source that is redundant to the first light source, in the following cases: The intersections of the illuminated flat surface and the optical axes of the two light sources A and B are not spaced apart from each other by more than a predetermined tolerance; and Furthermore, if the light fields achieved by the two light sources A and B do not deviate from each other by more than a predetermined tolerance, Illuminant B is redundant to Illuminant A.

[0080] Preferably, the following definition is used: two light fields do not deviate from one another by more than a predetermined tolerance, i.e., if, at each point of the illuminated surface, the two illuminances achieved by the two light sources at this point deviate from one another by at most this tolerance. The two intersection points and light fields relate to a situation in which no shadows are formed, preferably again with respect to the above-mentioned reference interval and with respect to a plane perpendicular to the optical central axis at the reference interval. At least in cases where the light sources of the lighting device cannot be moved relative to one another, the structure of the lighting device predetermines which light sources are more redundant with respect to which other light sources. This redundancy does not change during use of the lighting device.

[0081] It is also possible to use only the first criterion (near intersections) to identify when Illuminant B is redundant with Illuminant A. In many cases, the first criterion is met if the second criterion (near coincident light fields) is also met.

[0082] In a preferred configuration, for each light source of the light source set, information is additionally stored as to which other light source or light sources of the light source set are redundant for the first light source. This information as to which other light source or light sources are redundant for the first light source is predetermined by the structure of the lighting device. Of course, there may be no redundant light source for a light source.

[0083] The control equipment consists of: If a shadowing event is detected, the control device determines at least one light source, preferably a light source of the light source set, that is currently fully or at least partially shadowed. Typically, the shadowing event results in a shadow being cast on at least one light source. The control device searches for light sources, preferably each such redundant light source, of the set of light sources that are redundant to this or a given shadowed light source. To this end, the control device uses the information about the redundant light sources described immediately above. If the control device finds at least one such redundant light source, the control device checks which of the found redundant light sources is suitable for shadow formation compensation.

[0084] It may happen that no suitable redundant light source is found, and if at least one suitable redundant light source is found, the control device determines and uses a light source set consisting of at least one suitable redundant light source, preferably consisting of all suitable redundant light sources, as a subset.

[0085] The control device increases the maximum individual illuminance of each of the redundant, suitable light sources of the determined subset. The object of the present invention, or at least one object of the present invention, is that the achieved overall illuminance is equal to the illuminance setting.

[0086] Preferably, the control device searches for exactly one redundant suitable light source for each shadowed light source, and if n light sources are shadowed, the control device searches for up to n different redundant suitable light sources.

[0087] In many cases, a configuration using redundant light sources can quickly and often completely compensate for shadow formation, assuming that a sufficiently redundant and suitable light source can be found. This is because the information about which light source is redundant to which other light source is predetermined by the configuration, and the control device can obtain this information by read access. Furthermore, the computational capacity and therefore the computation time required by such a configuration are often relatively small.

[0088] In a further preferred configuration, the lighting device comprises at least one second light source and at least one further light source that is partially redundant to the second light source. This second light source may be the first light source or another light source as described further above with respect to the redundant light source. Light source B is partially redundant to light source A if at least one of the following conditions is met: The two intersections of the two optical axes of the two light sources are not spaced apart from each other by more than a predetermined tolerance. The intersection of the optical axis of light source B is centered on the intersection of the optical axis of light source A. x In other words: if at least two light sources are operated at their maximum possible individual illuminance and there is no shadow formation, the following applies: at the intersection of the optical axis of light source B and the illuminated surface, light source A achieves an individual illuminance that is at least x% of the maximum possible individual illuminance of light source A, and vice versa. The light fields achieved by these two light sources A and B deviate from each other beyond a predetermined tolerance.

[0089] In one implementation, two light sources are also partially redundant with respect to each other whenever they are redundant with respect to each other. In another implementation, two light sources are partially redundant with respect to each other only if the criteria listed above are met and the light sources are not redundant with respect to each other. It is also possible to use only configurations with redundant light sources or only configurations with partially redundant light sources.

[0090] In a configuration with partially redundant light sources, for each light source of the light source set it is additionally stored which other light sources are partially redundant for this light source. For each shadowed light source, the control device is configured to search for further light sources that are partially redundant for the shadowed light source and that are suitable for shadow formation compensation. Further steps correspond to those described immediately above in connection with redundant light sources.

[0091] Information about partially redundant shadow formation is also predetermined by the structure of the lighting device, and the control device can determine this information by read access. A configuration with redundant and / or partially redundant light sources limits the search space when searching for light sources that are currently suitable for shadow formation compensation. Therefore, in many cases, the control device needs to perform fewer calculations, which reduces calculation time and therefore in many cases leads to faster compensation of detected shadow formation compared to a configuration in which the search space consists of all non-shadowed light sources of the light source set.

[0092] The configurations with redundant light sources and the configurations with partially redundant light sources can be combined with each other in various ways: In one implementation, for each light source where shadows are formed, the control device searches in one working step for both redundant and partially redundant light sources that are suitable for shadow formation compensation and uses the set of all suitable redundant and partially redundant light sources as the subset.

[0093] In contrast, a different implementation of the combination described below defines a stepwise approach. In this different implementation, the light source set of the lighting device is configured as follows: for at least one first light source, there is at least one redundant light source, and for at least one second light source, there is at least one partially redundant light source. The control device can execute a first increase sequence and, if necessary, a second increase sequence. During the first increase sequence, the control device attempts to compensate for shadow formation using at least one redundant and / or partially redundant light source. The or each light source used during the first increase sequence additionally meets at least one predetermined additional criterion. After the first increase sequence, the control device determines or calculates what overall illuminance the lighting device has or will achieve and compares it with the detected illuminance setting.

[0094] If the current overall irradiance deviates from the detected irradiance setting by more than a predetermined tolerance, the control device executes a subsequent second increase sequence. During the second increase sequence, the control device attempts to additionally compensate for shadow formation using at least one redundant and / or partially redundant light source. The or each light source used during the second increase sequence does not meet the or each predetermined additional criterion. In many cases, executing the second increase sequence allows for relatively good compensation for shadow formation, but does not allow for as good compliance with the irradiance setting and / or optional light field diameter setting.

[0095] In the implementation just described, a first augmentation sequence is performed, which additionally searches for redundant and / or partially redundant light sources that satisfy the or each predetermined additional criterion. The or each predetermined additional criterion further limits the search space. If the first augmentation sequence alone does not provide sufficient compensation for shadow formation, a subsequent second augmentation sequence is performed, which similarly searches for redundant and / or partially redundant light sources, but without using the or each predetermined additional criterion. That is, the light sources found during the second augmentation sequence do not necessarily have to satisfy the or each additional criterion.

[0096] Various implementations are possible as to how this or any additional criterion for the first growth sequence can be configured.

[0097] In one configuration, this or another additional criterion for the first increase sequence is that the additional light source is redundant to the first light source. That is, in the first increase sequence, only light sources that are redundant to at least one light source of the light source set where a shadow is being formed are searched for. Partially redundant light sources are not considered in the first increase sequence, but are preferably considered in the second increase sequence. In other words, in the first increase sequence, only redundant light sources are searched for, and in the second increase sequence, partially redundant light sources are searched for, in particular light sources that have not already been found in the first increase sequence, i.e., generally partially redundant but not redundant light sources. Generally, shadow formation of a light source is compensated particularly well by additional light sources that are not switched off and are redundant to the light source where a shadow is being formed. However, in many cases, redundant light sources that are not switched off are not sufficient to fully compensate for shadow formation.

[0098] Further above, three criteria are listed for when light source B is partially redundant to light source A. In one implementation, the control device searches in one step for all light sources that are suitable for shadow formation compensation and that meet at least one of these three criteria. Preferably, this search is limited to suitable light sources that are not redundant to the light source that has been switched off and therefore have not already been found in the first increasing sequence. In another configuration, a descending order is predetermined between these criteria. First, the control device searches for suitable light sources that meet the highest-valued criterion for partial redundancy, then for suitable light sources that meet the second-highest criterion, and so on.

[0099] According to the present invention, the primary objective is that, through compensation for shadow formation, the value of the maximum overall illuminance currently achieved by the lighting device is close to, and ideally equal to, the detected illuminance setting. An optional further objective is that, additionally, the light field diameter setting is respected, and an optional third objective is that, additionally, the color temperature setting is respected. The light field diameter setting defines the light field diameter, and the color temperature setting defines the correlated color temperature that the lighting device should achieve.

[0100] The maximum objective and / or optional further objectives may not be achieved with only suitable, redundant and partially redundant suitable light sources. In one configuration, deviations are tolerated. In another configuration, the control device searches for further suitable light sources in this situation, i.e., light sources that are suitable for shadow formation compensation and that are not redundant or partially redundant to the light source on which the shadow is formed.

[0101] As already explained, the or at least one predetermined compensation criterion is that the further light source is redundant and / or partially redundant with respect to the shadowed light source. Further configurations of the or a compensation criterion are possible, which further configurations relate to groups of light sources. Compensation criteria using redundant and / or partially redundant light sources are combined with compensation criteria using groups of light sources.

[0102] In a configuration using light source groups, the light sources of the light source set are divided into at least two light source groups, and each light source of a light source group belongs to one and only one light source group.

[0103] The light sources of the light source group have the following property: they together generate a light field at the illuminated surface with a maximum illuminance. In one option, this maximum illuminance occurs at the intersection of the optical central axis of the lighting device with the illuminated surface. In another option, this maximum illuminance occurs in a circle around this intersection. This property is satisfied at least in the following cases: If the illuminated surface is perpendicular to the optical central axis at the reference distance, All light sources in the light source group operate at the same maximum individual irradiance, and If no shadow-forming events are occurring, This applies to:

[0104] The compensation criterion or a compensation criterion is as follows: the further light source and the shadowed light source or the shadowed light source belong to the same light source group. This configuration makes it possible in many cases to keep the light field diameter achieved by the entire lighting device at the illuminated surface approximately the same despite shadow formation, or at least to keep the light field diameter achieved by the entire lighting device at the illuminated surface approximately the same in many cases despite shadow formation.

[0105] Other or additional compensation criteria are possible. A possible additional compensation criterion is the correlated color temperature. Typically, each light source in a lighting device has one correlated color temperature. Preferably, the light sources in a light source set have at least two different correlated color temperatures, for example, cool white and warm white. The overall correlated color temperature of the lighting device is generated by the superposition of the correlated color temperatures of the switched-on light sources. A possible additional compensation criterion is that the additional light source has the same correlated color temperature as the light source where the shadow is formed. This additional compensation criterion causes the color temperature of the lighting device to change relatively little despite the shadow formation in many cases.

[0106] A possible further compensation criterion is that the further light source currently operates with a relatively low maximum individual irradiance, for example at most half the maximum possible individual irradiance, or even at most only a quarter of the maximum possible individual irradiance. If the maximum individual irradiance of this light source is increased, this increase often makes a particularly large contribution to compensating for shadow formation.

[0107] According to the present invention, the lighting device includes a distance measurement assembly. The control device determines a shadow-forming region, which is a region on the illuminated surface where a shadow is formed by an object between the lighting device and the illuminated surface. "Shadow formation" means that the overall illuminance at the surface in the shadow-forming region is reduced by at least one predetermined absolute or relative limit due to the shadow formation. To this end, the control device can receive and evaluate signals from the distance measurement assembly. Preferably, the control device determines the contour of the shadow-forming object in a plane perpendicular to the optical central axis, and also determines the distance between the lighting device and this contour and / or the distance between this contour and the illuminated surface. In one configuration, the control device can measure a topological profile of the region between the light source set and the illuminated surface. To measure the topological profile, the control device uses signals from the distance measurement assembly. When no shadow-forming object is present in the region between the lighting device and the illuminated surface, this profile is equal to the profile of the illuminated surface, e.g., the profile of an illuminated patient on a surgical table. A shadow-forming object alters the topology profile. The control device can evaluate the determined topology profile, preferably at the sampling frequency described above. The control device can detect a shadow-forming event in conjunction with evaluating the topology profile. In many cases, a shadow-forming object will abruptly change the topology profile, and the control device will detect the abrupt change. Preferably, the control device further uses the topology profile to determine a shadow-forming region on the illuminated surface.

[0108] According to the invention, the control device detects and uses information about the light sources of the light source set, in particular each possible maximum individual illuminance, and the position and / or orientation of the optical axis relative to the central optical axis of the lighting device. In one configuration, this information is stored in a data memory, optionally also storing each correlated color temperature of each light source. The control device has at least temporary read access to the data memory and detects this information by means of read access to the data memory.

[0109] The data memory configuration allows the same program to be used for shadow compensation for different lighting devices. The structure of a specific lighting device is taken into account by the corresponding information in the data memory, and this program can be kept unchanged. As already mentioned above, the control device preferably executes this program on a processor, and the control device also drives and controls the lighting devices and performs shadow compensation as needed.

[0110] According to the present invention, the control device can detect shadow formation events and at least partially compensate for the detected shadow formation. In the configurations described so far, the shadow formation event is caused by at least one object reaching an area between the lighting device and the illuminated surface. In some configurations, the configuration described immediately above for compensating for shadow formation is used in the same manner to compensate for the failure of at least one light source. Unlike the configuration described immediately above, the control device generally does not use a signal from a distance measurement assembly to detect a light source failure, but rather evaluates a signal from the light source, e.g., an event in which the light source has an electrical resistance above a predetermined limit. The steps for compensating for the failure of at least one light source are the same as the steps for compensating for shadow formation. In particular, the control device determines which area on the illuminated surface is currently affected by the light source failure. This configuration for compensating for the failure of at least one light source often allows the lighting device to continue to be used until the or each failed light source is replaced.

[0111] Hereinafter, the present invention will be described based on examples. [Brief explanation of the drawings]

[0112] [Figure 1] 1 shows an illumination device according to the invention in an embodiment in which the central optical axis is perpendicular to the plane of the drawing and the observer is looking at the light source of the illumination device; [Figure 2] 1 shows the optical axis and light cone of a light source for two position groups Pos.1 and Pos.4. [Figure 3] FIG. 3 shows the achieved light field for the two positions of FIG. 2 using a graph in the xz plane. [Figure 4] 10A and 10B are diagrams showing the optical axes and light cones of the light sources of two position groups Pos.2 and Pos.5. [Figure 5a] 5 shows, by contrast, a first realization of how the light fields of the light sources of the two position groups of FIG. 4 are positioned relative to each other. [Figure 5b] 5 shows, by contrast, a first realization of how the light fields of the light sources of the two position groups of FIG. 4 are positioned relative to each other. [Figure 6a] 5 shows, by contrast, a second realization of how the light fields of the light sources of the two position groups of FIG. 4 are positioned relative to each other. [Figure 6b] 5 shows, by contrast, a second realization of how the light fields of the light sources of the two position groups of FIG. 4 are positioned relative to each other. [Figure 7a] 5 shows, by contrast, a third realization of how the light fields of the light sources of the two position groups of FIG. 4 are positioned relative to each other. [Figure 7b] 5 shows, by contrast, a third realization of how the light fields of the light sources of the two position groups of FIG. 4 are positioned relative to each other. [Figure 8]FIG. 5 shows the achieved light field for the two positions of FIG. 4 using a graph in the xz plane. [Figure 9] 10 shows the optical axes and light cones of the light sources of two position groups Pos.3 and Pos.6. [Figure 10] FIG. 10 shows the achieved light fields for the two positions of FIG. 9 using a graph in the xz plane. [Figure 11] FIG. 1 is a diagram showing a first example of an object that forms a shadow. [Figure 12] FIG. 10 is a diagram showing a second example of an object that forms a shadow. [Figure 13] FIG. 10 is a diagram showing a third example of an object that forms a shadow. DETAILED DESCRIPTION OF THE INVENTION

[0113] In this embodiment, the invention is used in a lighting device for an operating room, i.e., a surgical lamp. The lighting device illuminates an operating table on which a patient to be treated is placed. The lighting device is rotationally symmetrical about a central axis. The lighting device is attached to the ceiling using a holder and can be freely positioned and oriented in space.

[0114] The lighting device generates a light field on an illuminated surface. This illuminated surface can be an operating table or a surface of a patient on an operating table facing the lighting device. In the figures and the following description, a flat illuminated surface of the object is shown in a simplified form and will be described accordingly. The object is designated Obj, and the flat illuminated surface emerging towards the lighting device is designated Ob. The present invention does not assume that the illuminated surface is a plane.

[0115] FIG. 1 shows a schematic and exemplary illustration of a lighting device 100 of this embodiment, in which the central optical axis MA of the lighting device 100 is perpendicular to the drawing plane of FIG. 1 . A number of individual light sources a.1, ..., a.6, b.1, ..., b.6, ... are visible, each represented by a circle (ring) and fixed to a support 8 with a circular cross section. These circles extend in the drawing plane of FIG. 1 . An observer in FIG. 1 looks toward the light sources a.1, ..., a.6, b.1, ..., b.6, ... parallel to the central axis MA. A schematically shown grip 5 is attached to the surface of the support 8 facing the observer, by means of which the lighting device 100 is moved in space. In this embodiment, the grip 5 has the shape of a truncated cone, but the grip may also have the shape of, for example, a cylinder, a prism, or a truncated prism.

[0116] In this embodiment, each light source a.1, ..., a.6, b.1, ..., b.6, ... is fixedly attached to the support 8. Therefore, it is not possible to move one light source relative to the other light sources of the lighting device 100. This configuration eliminates actuators for the light sources. However, it would also be possible for each individual light source or at least one group of light sources to be moved relative to the support 8, and preferably also relative to the remaining light sources, by means of one actuator each (not shown). The actuators in particular allow the light field generated by the light source to be moved relative to the illuminated surface Ob, without moving the support 8.

[0117] Each individual light source a.1, ..., a.6, b.1, ..., b.6, ... has an optical central axis, hereinafter referred to as "optical axis", to distinguish it from the optical central axis MA of the illumination device 100. These light beams together form a truncated cone of increasing diameter from the light sources a.1, ..., a.6, b.1, ..., b.6, ..., often forming a cylinder, or even a truncated cone of first decreasing diameter and then increasing again from the light sources a.1, ..., a.6, b.1, ..., b.6, .... For simplicity, this is referred to hereinafter as a "light cone" having an "angle of divergence". The term "luminous flux" would also be appropriate. That is, each individual light source a.1, ..., a.6, b.1, ..., b.6, ... generates a light cone. For example, LA a.4 indicates the optical axis of the light source a.4, and Lk a.4 shows the light cone of light source a.4. The illustrated light cone Lk a.4 On the outer peripheral surface of the a.4 10% of the maximum individual illuminance obtainable along the

[0118] Figures 2, 4 and 9 each show a cross section taken along line II in Figure 1. The central axis MA lies in the drawing plane of Figures 2, 4 and 9. The figures are not necessarily drawn to scale.

[0119] In this embodiment, the lighting device 100 comprises 66 individual light sources. Naturally, the invention can also be realized with any other reasonable number of light sources. The 66 light sources are divided into a number of configuration groups on the one hand and a number of position groups on the other hand, as will be explained below with reference to FIG. 1.

[0120] In the illustrated example, the lighting device 100 includes six groups Bg.a, ..., Bg.e, which are arranged concentrically around the central axis MA of the lighting device 100, emanate from the central axis MA in the form of beams, and are attached to the support 8. The groups Bg.a, ..., Bg.e may also be arranged differently from the concentric arrangement around the central axis MA. Each group Bg,a, ..., Bg,e includes eleven light sources in the illustrated implementation. Group Bg.a includes eleven light sources a.1, ..., a.6, group Bg.b includes eleven light sources b.1, ..., b.6, etc.

[0121] It should be understood that the arrangement and configuration of the groups Bg.a, ..., Bg.e are merely exemplary. Naturally, other numbers of groups and / or other numbers of light sources are possible. It is also possible to use multiple groups with a total of at least two different numbers of light sources a.1, ..., a.6, b.1, ..., b.6, ...

[0122] Preferably, each individual component group can be replaced independently of the other components, i.e., one old component group can be removed from the support 8 and one new component group can be inserted.

[0123] In this embodiment, the six component groups Bg.a, ..., Bg.e are fixedly arranged on the circular support 8 of the lighting device 100, so that one component group Bg.a, ..., Bg.e cannot be moved relative to another component group. The 11 light sources in each component group Bg.a, ..., Bg.e are fixedly attached to the component group Bg.a, ..., Bg.e, so that the light sources cannot be moved relative to other light sources in the same component group.

[0124] The 66 light sources of the lighting device 100 are further divided into six different position groups Pos.1, ..., Pos.6 in this example. This number should also be understood as merely exemplary. Each light source belongs, on the one hand, to exactly one (one and only one) configuration group Bg.a, ..., Bg.e, and, on the other hand, to exactly one position group Pos.1, ..., Pos.6.

[0125] In this embodiment, all of the light sources in the position groups Pos.1, ..., Pos.6 have the same distance from the central axis MA of the lighting device 100. The six position groups Pos.1, ..., Pos.6 are arranged concentrically around the central axis MA. The innermost position group Pos.1 forms a ring around the grip 5, and the remaining position groups Pos.2, ..., Pos.6 form concentric rings around the innermost position group Pos.1. Since each light source belongs to exactly one position group, the innermost position group Pos.1 contains six light sources, and the remaining five position groups Pos.2, ..., Pos.6 each contain 12 light sources.

[0126] The position groups Pos.1, ..., Pos.6 in this embodiment form light source groups within the meaning of the claims. The optical axes of the light sources of a position group are preferably arranged parallel to one another.

[0127] The numbering of the light sources indicates which configuration group and which position group each light source belongs to: light sources ax, bx, ..., fx belong to the position group Pos.x (x = 1, ..., 6) and to the configuration groups a, b, ..., f.

[0128] As can be seen in FIG. 1 , in this embodiment, except for the light source in the inner position group Pos.1, each two individual light sources belong to the same configuration group and the same position group. The optical axes of these two light sources are ideally arranged to intersect at a reference interval. On a plane at the reference interval, these two light sources ideally achieve two light fields that coincide except for an offset perpendicular to the optical axis and, optionally, except for a rotation about the optical axis. Therefore, these two light sources are hereinafter treated as one light source and therefore have the same name. Optionally, these two light sources emit light with different correlated color temperatures, which are superimposed to generate the overall color temperature of the two light sources.

[0129] Preferably, the same angle always forms between the optical axes of the light sources of the position groups Pos.1, ..., Pos.6 and the central optical axis MA of the lighting device 100. The optical axes of the light sources or at least some of the light sources may be arranged at an angle to the central optical axis MA. If the angle between the optical axes and the central axis MA is always the same, the light cones and light fields generated together by these light sources of a position group are idealized to be rotationally symmetrical with respect to the central optical axis MA.

[0130] For clarity, the light cones of two different groups of positions are shown with different hatching in Figures 2, 4 and 9. Additionally, an intersection point S is shown, at which the central optical axis MA of the illumination device 100 intersects with the surface Ob being illuminated.

[0131] Figures 3, 8 and 10 each show the generated light fields, which will be explained in more detail below. The representation shows one light field in each case in the xz plane. The intersection point S is located at the origin of the coordinate system. The y-axis is perpendicular to the drawing plane. On the z-axis, the achieved illuminance Ev is plotted.

[0132] In this embodiment, the light sources a.1, ..., a.6, b.1, ..., b.6, ... are attached to the support 8 in such a way that the optical axes and light cones of the light sources of one position group Pos.2, ..., Pos.6 are arranged rotationally symmetrically around the central axis MA of the lighting device 100. The representations of Figures 2, 4 and 9 therefore also apply correspondingly to other cross-sectional views, such as for example the cross-sectional views of the component groups Bg.c and Bg.f, in which the central optical axis MA lies in the drawing plane.

[0133] Preferably, each of the light sources a.1, ..., a.6, b.1, ..., b.6, ... directs light along an optical axis LA. a.1 ,…,LA a.6 ,LA b.1 ,…,LA b.6 The light cones emitted from the light sources a.1, ..., a.6, b.1, ..., b.6, ... are radiated along the optical axis LA. a.1 ,…,LA a.6 ,LA b.1 ,…,LA b.6 , ..., and the angle is preferably less than 20 degrees, particularly preferably less than 15 degrees, and particularly preferably 5 to 12.5 degrees.

[0134] Each of the light sources a.1, ..., a.6, b.1, ..., b.6, ... is generally aligned with its own optical axis LA a.1 ,…,LA a.6 ,LA b.1 ,…,LA b.6 , ... is achieved. Local minima of the individual illuminance may also be achieved on the optical axis. Ideally, this current maximum individual illuminance can be varied steplessly between zero and the maximum possible individual illuminance of the light source, and in particular can be varied independently of the current maximum individual illuminance of each of the other light sources. It is also possible for each maximum individual illuminance of each light source to be varied in multiple steps, and in particular, again independently of the maximum individual illuminance of each of the other light sources. For example, 8 bits each = 256 different steps are possible. However, at least each light source can be switched on and off independently of each of the other light sources.

[0135] In one configuration, all light sources a.1, ..., a.6, b.1, ..., b.6, ... are of the same construction. In contrast, in a preferred configuration, two different types of light sources are used, where the first type of light source emits warm white light and the second type of light source emits cool white light. In one implementation, all light sources achieve the same maximum possible individual illuminance and have the same light divergence angle. The light sources may differ with respect to the maximum possible individual illuminance and / or light divergence angle.

[0136] A signal processing control device 10 (control unit), shown only diagrammatically, is able to drive and control each individual light source a.1, ..., a.6, b.1, ..., b.6, ... of the lighting device 100, so that in particular the current maximum individual illuminance generated by the light sources a.1, ..., a.6, b.1, ..., b.6, ... on the illuminated surface Ob is changed independently of each current maximum individual illuminance of each further light source.

[0137] Preferably, the light source is operated in a pulse-controlled manner. To vary the maximum individual irradiance of the light source, the control device 10 can also vary the pulse width or pulse duration or pulse frequency of the electric pulses. In the case of pulse width modulation, the ratio between the duration of one electric pulse and the duration of the pause between two electric pulses is varied. It is also possible for the control device 10 to vary the intensity of the current flowing through the light source or the applied voltage.

[0138] In one implementation, the control device 10 has at least temporary read access to the data memory 11. By means of this read access to the data memory 11 and optionally subsequent calculations, the control device 10 obtains the following information for each light source a.1, ..., a.6, b.1, ..., b.6, ... respectively: Maximum possible individual illuminance, How the current maximum individual irradiance is related to the variable electrical parameters driving and controlling the light source, e.g. pulse width, current intensity and / or voltage; their respective positions on the support 8, in particular their distance from the central optical axis MA of the illumination device 100 and their rotational positions relative to the central optical axis MA of the illumination device 100; the orientation of the optical axis relative to the central axis MA, the light divergence angle, and Correlated color temperature can be obtained.

[0139] This information is predetermined by the structure of the lighting device 100 or is determined beforehand experimentally or theoretically. In one implementation, an algorithm in the form of a computer program is stored in this data memory 11, which the control device 10 applies and which is valid for each similar lighting device 100. The information listed immediately above regarding the light sources is implemented in this algorithm in a fixed manner. In another implementation, this algorithm is stored in the control device 10 in a different manner. For simplicity, it will be stated hereinafter that the control device 10 reads the information regarding the individual light sources by means of a read access to the data memory 11.

[0140] Information from the data memory 11 is used to adjust the illumination device 100 so that it ideally produces the desired overall light field at the illuminated surface Ob, and these information do not change during operation and therefore remain valid unless the illumination device 100 is reconfigured.

[0141] As already explained, the control device 10 can change the current maximum individual irradiance of a light source independently of the current maximum individual irradiance of each further light source, in particular preferably steplessly or in more than 100 different steps between the maximum possible individual irradiance and zero. In one implementation, these current maximum individual irradiances are stored in a data memory 12 to which the control device 10 has at least temporary read and write access. When the control device 10 changes the current maximum individual irradiance of a light source, the control device 10 also changes the corresponding entry in this data memory 12.

[0142] The lighting device 100 comprises an input unit 20, for example an assembly with a touch-sensitive screen (touch screen) and / or a number of buttons. This input unit 20 is arranged, for example, on the support 8, on the grip 5 or spatially separated from the support 8 and the grip 5, as exemplarily shown in Fig. 1. By means of this input unit 20, a user can configure the lighting that the lighting device 100 should generate on the illuminated surface Ob. In particular, the user can configure the following parameters: An illuminance setting (Ev in FIG. 1 ) that is the current maximum overall illuminance that the lighting device 100 should achieve at the reference interval; Light field diameter d x where the term light field diameter is defined further above, and preferably x=10%. x (In Figure 1: dx), and Correlated color temperature (Temperature in Figure 1) correlated with the light spectrum of the lighting device At least one, and preferably each, of the above may be assigned a value, for example by means of a slide controller or rotary knob, respectively.

[0143] Alternatively, the user can increase or decrease the current value without necessarily having to read the current value or enter the desired value.

[0144] Additionally or alternatively, a higher-level control unit may assign a different value to at least one of these parameters, preferably related to the reference distance given above, for example 1 m, as well as to a flat illuminated surface Ob perpendicular to the central optical axis MA.

[0145] The control device 10 detects these settings of the user or a higher-level control unit and drives the light sources a.1, ..., a.6, b.1, ..., b.6, ... with the goal that the lighting device 100 will generate, on the illuminated surface Ob, a light field with actual values ​​equal to the settings. Generally, this goal is only approximately achieved. The light field of the lighting device 100, in particular the light field diameter and maximum overall illuminance as well as the correlated color temperature, is the result of the superposition of the light fields and correlated color temperatures of the individual light sources a.1, ..., a.6, b.1, ..., b.6, .... To adjust the light field of the lighting device 100, the control device 10 drives the individual light sources a.1, ..., a.6, b.1, ..., b.6, ... as described above, and in particular changes the current maximum individual illuminance and, optionally, the correlated color temperature of each light source, as needed. To change the correlated color temperature of the lighting device 100, the control device 10 preferably increases or decreases the maximum individual illuminance of each of the warm white or cool white light sources.

[0146] FIG. 2 exemplarily shows the optical axes LA of two light sources a.1 and d.1 of the position group Pos.1. a.1 ,LA d.1 and light cone Lk a.1 ,Lk d.1 and the optical axis LA of the two light sources a.4 and d.4 of the position group Pos.4 a.4 ,LA d.4 and light cone Lk a.4 ,Lk d.4 The central optical axis MA of the illumination device 100 and the optical axes of the four light sources lie in the drawing plane of FIG.

[0147] The two position groups Pos.1 and Pos.4 are arranged such that the respective optical axes of the light sources of the position group Pos.1 or of the position group Pos.4 intersect the illuminated surface Ob at the intersection point S. This is shown exemplarily in Figure 2 for the four shown light sources a.1, d.1, a.4, d.4.

[0148] 3 shows two light fields Lf1 and Lf4 generated together by the light sources at positions Pos.1 or Pos.4. The central axes MA of the four light sources a.1, ..., d.4 shown in FIG. a.1 ,…,MA d.4 intersect at the intersection point S of the optical central axis MA and the illuminated surface Ob of the object Obj. The illuminance Ev is therefore greatest at this intersection point S and decreases according to the shape of a bell curve with increasing distance dist. In the illustrated example, the two light fields Lf1 and Lf4 are on the one hand geometrically coincident, i.e. in particular with the same maximum individual illuminance and the same light field diameter d on the surface Ob. 10 and on the other hand they also agree with respect to color temperature. The two groups of positions Pos.1 and Pos.4 are therefore (intentionally) redundant, since they generate the same light field Lf1 or Lf4 on the surface Ob.

[0149] FIG. 4 shows four optical axes LA of four light sources a.2, a.2, d.5, and d.5 in position groups Pos.2 and Pos.5. a.2 ,LA a.5 ,LA d. 2,LA d.5 and four light cones Lk a.2 ,Lk a.5 ,Lk d.2 ,Lk d.5 The optical axis LA of the light sources a.2 and a.5 is shown. a.2 and L.A. a.5 intersects the illuminated surface Ob of the object Obj at the same intersection point S.1, which has a distance r from the central axis MA and therefore from the intersection point S. The optical axes LA of the light sources d.2 and d.5 d.2 and L.A. d.5 also intersects the illuminated surface Ob of the object Obj at the same intersection point S.2, which has the same distance r to the central axis MA and is also spaced apart from the optical axis MA. a.2 and M.A. a.5 The intersection point S.1 has a spacing of 2*r.

[0150] Thus, each light field Lf2 and Lf5 in the plane in which the optical axes lie has two maxima, each spaced apart by a distance r from the central axis MA (see FIG. 8). These maxima form a circle with a radius r. Generally, the intersections S.1 and S.2 of the optical axes of the light sources in the position groups Pos.2 and Pos.5 form a circle centered on the intersection S of the optical central axis MA and the surface Ob. The two position groups Pos.2 and Pos.5 are partially redundant because they have two light fields Lf2 and Lf5 around the same circle. Although this circle has a center point S, one light field Lf2 does not exactly coincide with the other light field Lf5, especially if the light sources differ from each other in terms of their maximum individual illuminance and / or light field diameter and / or correlated color temperature. For example, the light field of one light source is rotated around the optical central axis MA relative to the light field of the other light source.

[0151] 5, 6 and 7 exemplarily show three alternative realizations of how the six light fields of the six light sources of position group Pos.5 can be positioned relative to the six light fields of the light sources of position group Pos.2 (see FIG. 4). The central axis MA of the illumination device 100 is perpendicular to the drawing plane of FIGS. 5, 6 and 7. The light field diameter d of the light fields generated by the six light sources of position group Pos.2 is 10 (Left) and the light field diameter d of the light field generated by the six light sources in position group Pos.5 10 (Right) and (left) are shown, respectively.

[0152] In the example of FIG. 5, the six light fields are matched in pairs, i.e., each light field of the light source at position group Pos.2 matches each light field of the light source at position group Pos.5 in terms of shape, position, and especially light field diameter. In the example of FIG. 6, the light field of the light source at position group Pos.5 is rotated clockwise by approximately 20 degrees relative to the six light fields of the light source at position group Pos.2 and is not at the same position on surface Ob. More precisely: each light field of the light source at position group Pos.5 has the same shape, especially the same light field diameter, as the light field of the light source at position group Pos.6, but does not have the same position and is a light field rotated around the central axis MA. In the example of FIG. 7, the six light fields of the light source at position group Pos.5 each have a larger light field diameter than the six light fields of the light source at position group Pos.2. Furthermore, the light fields of the light source at position group Pos.5 are rotated by approximately 20 degrees relative to the light fields of the light source at position group Pos.2. Of course, other situations are possible, but they have in common that the maxima of the light field of the light source at position group Pos.2 and the maxima of the light field of the light source at position group Pos.5 are located on the same circle centered on the optical central axis MA.

[0153] FIG. 9 shows the four optical axes LA of the four light sources a.3, a.6, d.3, and d.6. a.3 ,LA a.6 ,LA d.3 ,LA d.6 and four light cones Lk a.3 ,Lk a.6 ,Lk d.3 ,Lk d.6 10 shows two light fields Lf3 and Lf6 generated together by the light sources at positions Pos.3 and Pos.6. The central axis LA a.3 and L.A. d.3 intersects the illuminated surface Ob at two intersection points S.5 and S.6, which are spaced r1 and 2*r1 from the central axis MA, respectively. a.6 and M.A. d.6Similarly, intersects with the illuminated surface Ob at two intersection points S.3 and S.4, which are spaced apart from the central axis MA by r2 and 2*r2, respectively (see FIG. 9). r2>r1 holds. In total, FIG. 9 shows four different, spaced apart intersection points S.3,...,S.6.

[0154] The light field Lf3 is concentrically surrounded by the light field Lf6. The maxima of the light field Lf3 are spaced apart by r1 relative to the central axis MA, and the maxima of the light field Lf6 are spaced apart by r2. The two sets of positions Pos.3 and Pos.6 are not redundant because they generate different light fields Lf3 and Lf6, respectively. These two light fields Lf3 and Lf6 are shown in FIG. 10. In the illustrated example, the sets of positions Pos.3 and Pos.6 are not even partially redundant because the maxima are located on different annuli.

[0155] In this embodiment, the lighting device 100 includes at least one, preferably multiple, distance measuring devices. The or each distance measuring device can contactlessly measure the distance between itself and a light-scattering surface. Preferably, the or each distance measuring device emits an electromagnetic beam, preferably in the infrared range, optionally in the ultraviolet range, toward the illuminated surface Ob. A portion of the scattered beam reaches the distance measuring device, which measures the propagation time and derives the distance therefrom. By way of example, FIG. 1 shows a central distance measuring device dm and one distance measuring device dm.2, ..., dm.6 for each position group Pos.2, ..., Pos.6, respectively. Other principles for contactless distance measurement are also possible.

[0156] The central distance measurer dm and the or each further distance measurer dm.2, ..., dm.6 are in this example fixedly attached to the support 8, so that the position and orientation of the distance measurers dm, dm.2, ..., dm.6, ... relative to the support 8 are unchanged. The above-mentioned data memory 11 stores the respective position and orientation of each distance measurer on the support 8. As already mentioned, the control device 10 has read access to this data memory 11.

[0157] In a preferred configuration, the or at least one distance measurer of the lighting device 100 is capable of generating a topological profile of the illuminated surface Ob. Such distance measurer implementations are known under the name "Time-of-Flight Sensors". Laser scanners and 3D camera systems are also suitable in many implementations for generating respective topological profiles. Several distance measurers may jointly generate signals from which the control device 10 determines the topological profile.

[0158] An object may reach the area between the illumination device 100 and the illuminated surface Ob, i.e., in this case, the patient on the operating table. This object may, in particular, be a body part of the doctor performing the treatment or a medical instrument. This object casts a shadow. Generally, a shadow-forming object reaches each light cone of at least one light source, thus reducing the overall illumination in some areas of the achieved overall light field. Figures 11, 12, and 13 show three examples for each positioning of the shadow-forming object AO from the observation direction of Figure 1. The shadow-forming object AO is shown only schematically. In reality, the shadow-forming object is often larger than the object shown here.

[0159] Since the lighting device 100 has many (here 66) different light sources, the optical axes of which are not all arranged parallel to one another, such shadow formation generally does not result in sharp drop shadows on the illuminated surface Ob, or even in the complete absence of illumination in previously illuminated areas of the surface Ob. Nevertheless, shadow formation is undesirable. The control device 10 automatically compensates for shadow formation, at least in part. How this objective is achieved will be explained below.

[0160] The control device 10 receives signals from the distance measuring devices dm, dm.1, ..., dm.6 and evaluates these signals, hereinafter referred to for brevity as "distance measuring assembly signals". The control device 10 automatically determines which light source of the lighting device 100 is casting a shadow. For this purpose, the assumption is used that a shadow-casting object AO scatters and opposes the incident electromagnetic beam, and thus light in the visible range. Therefore, a shadow-casting object AO shortens, and generally sharply shortens, the measured distance between at least one distance measuring device dm, dm.1, ..., dm.6 and the light-scattering surface.

[0161] In one configuration, the control device 10 only considers values ​​for the distance between the distance measuring device and the light scattering object that lie within a predetermined value range, which is a portion of the interval between 0 m and the reference distance. For example, if the reference distance is 1 m, this value range is between 0.2 m and 0.8 m. Shadow-forming objects generally have a distance to the lighting device 100 that lies within this value range, and both the operating table Ob and the patient Ob on the operating table generally have a longer distance.

[0162] Preferably, the control device 10 repeatedly determines which light sources are currently casting shadows, for example at a predetermined constant sampling frequency. Of course, there may be cases where no shadows are currently casting on a light source.

[0163] Preferably, the control device 10 determines, at least approximately, the contour of the shadow-forming object AO and the position of this contour in a plane perpendicular to the central optical axis MA. This plane preferably has a reference distance relative to the lighting device 100. The determined contour approximately locates which area of ​​the illuminated surface is shadowed by the object AO, i.e., locates the shadow-forming area. This contour can be approximately represented by a rectangle, a circle, or any other suitable geometric figure, which is located in a plane perpendicular to the central optical axis MA at the reference distance. To determine this contour, the control device 10 uses signals from a distance measurement assembly. As already explained, each distance measurer measures at least the distance between itself and the illuminated surface Ob or the light-scattering object AO. Optionally, the control device 10 determines a topological profile of the illuminated surface. The shadow-forming object AO protrudes from the illuminated surface Ob, i.e., has a shorter distance relative to the lighting device 100 than the illuminated surface Ob.

[0164] As already mentioned above, in this embodiment the control device 10 has at least temporary read access to a data memory 11, which contains: For each light source, the maximum possible individual illuminance, the position and orientation of the optical axis relative to the central axis MA, the light divergence angle and correlated color temperature, and For each distance measuring device dm, dm.2, ..., dm.6, the position and orientation of the direction of observation (measuring direction) of this distance measuring device relative to the central axis MA From the measured intervals and the information just described stored in the data memory 11, the control device 10 derives information on which light sources a.1, ..., a.6, b.1, ..., b.6, ... are currently shadowed. In one configuration, a light source is assessed as being shadowed if the object AO reaches the optical axis of the light source, and in another configuration, if the object AO reaches the optical axis of the light source (light field diameter d 10) is evaluated as casting a shadow on the light source (see Figures 2, 4 and 9).

[0165] As already explained, the user or a higher-level control unit can also provide settings for the lighting device 100, in particular the following parameters: Maximum overall illumination, Light field diameter d x , preferably d 10 , and Correlated color temperature You can provide settings for

[0166] The control device 10 automatically compensates for shadow formation with the objective that the parameters listed immediately above have the same value after compensation as they did before shadow formation. In many cases, this objective is not achievable, or at least not ideally achievable. Therefore, the control device 10 applies the following gradation between these objectives: The main objective is that the maximum overall illuminance of the lighting device 100 remains the same. Furthermore, the point at which this maximum overall illuminance is achieved remains the same. Typically, this is the intersection point S. The objective of medium importance is additionally to reduce the light field diameter d of the lighting device 100. x At the very least, the objective is to keep the optical field diameter d x is held constant for x=10%, optionally additionally for x=50% or another value for x. An objective with a relatively low priority is that the light field of the lighting device 100 remains unchanged. An objective having a lower priority is additionally that the correlated color temperature of the lighting device 100 remains the same or at least that any change is not perceptible to humans.

[0167] Note: In many cases, each light source has one of two possible correlated color temperatures, e.g., warm white and cool white. The cool white and warm white light sources are uniformly distributed on the support 8. Therefore, in many cases, shadow formation does not alter the correlated color temperature of the lighting device 100 in a way that is perceptible to humans. Therefore, often, achieving the first two objectives is enough to achieve the last goal, and no special drive control is required.

[0168] A boundary condition is that the shadow formation compensation requires only a small amount of calculation time. More precisely: the shadow formation compensation should be performed within a period with a predetermined maximum duration. Preferably, the compensation also requires relatively little computational power, so that relatively simple chips or processors can be used. The control device 10 repeatedly performs the shadow formation compensation, for example at the sampling frequency mentioned immediately above.

[0169] Preferably, the control device 10 switches off the shadowed light source and keeps it switched off as long as this light source is shadowed, which on the one hand reduces the energy and heat input to the illuminated objects, in particular the shadowed objects, and on the other hand shortens the calculation times compared to a configuration in which the shadowed light source is kept switched on, with a reduced maximum individual illuminance.

[0170] In this embodiment, the maximum overall illuminance of the lighting device 100, the light field diameter d x and correlated color temperature are not measured but are calculated by the control device 10. As already mentioned, the maximum overall illuminance of the lighting device 100, the light field diameter d x and the correlated color temperature is caused by the superposition of the light fields of the light sources, more precisely of the light sources that are currently switched on.

[0171] By means of read access to the above-mentioned data memory 11, the control device 10 determines the respective positions and orientations of the optical axes, the maximum individual illuminance possible; the optical field diameter d of each light source; x and correlated color temperature, which in one implementation are kept constant, while the control device 10 determines the current maximum individual illuminance of each light source by read access to the data memory 12. The control device 10 can at least change, for example increase, each current maximum individual illuminance of each light source up to the maximum possible individual illuminance. In another implementation, the control device 10 can additionally drive and control actuators for the light sources, thereby changing the orientation of the optical axis of this light source relative to the central axis MA.

[0172] It is conceivable that the control device 10 has read access to a table present in a form that can be evaluated by the computer, which contains one entry for each possible shadow formation of the light sources of the lighting device 100 and the resulting operational intervention that compensates for this shadow formation and adheres to the objectives listed above. However, in the case of N light sources, this table can theoretically contain 2 N different entries, so that for each possible shadow formation there is an appropriate entry. For 66 light sources, this is 7*10 19 entries. Such a large table cannot be evaluated quickly enough in many cases, so the control device 10 applies a simple heuristic.

[0173] In the following, the terms "redundant" and "partially redundant" are used in particular both for individual light sources and for groups of positions.

[0174] Two light sources are mutually redundant if they generate identical light fields, except for a tolerance, at the illuminated surface Ob. This surface Ob is perpendicular to the central axis MA of the illumination device 100 and is at a reference distance from the illumination device 100. Two groups of positions are mutually redundant if their light sources generate identical light fields and for each light source in one group of positions there is one redundant light source in the other group of positions. In the example of Figure 5, the two groups of positions Pos.2 and Pos.5 are mutually redundant.

[0175] Two light sources are partially redundant to one another if their light fields overlap but are not identical and / or the light sources have different correlated color temperatures. In particular, the light fields may differ with respect to geometric shape and / or maximum individual illuminance and / or light field diameter. Correspondingly, two groups of locations are partially redundant to one another if they generate identical light fields on the illuminated surface and for each light source in one group of locations there is at least one partially redundant light source in the other group of locations, but no redundant light sources.

[0176] The control device 10 first attempts to replace each shadowed light source with a non-shadowed light source, where the substitute light source is redundant to the shadowed light source. If n light sources are shadowed, this approach requires at least n non-shadowed, redundant light sources for compensation. The light source y is aligned with the light source x along the optical axis LA of the two light sources. x and L.A. y intersects the illuminated surface Ob at the same point and is exposed to the same light field Lf x and Lf y and therefore have the same light field diameter and the same correlated color temperature. Note: In this example, the light source that is partially shadowed is switched off until shadow formation has ceased again.

[0177] The control device 10 uses information about which light sources belong to which position group. For each light source x.4 in position group Pos.4, there is one redundant light source a.1, ..., f.1 in position group Pos.1 (see Figures 2 and 3). That is, if a light source in position group Pos.4 is shadowed, the control device 10 determines the non-shadowed light sources in position group Pos.1, and vice versa. Only in position group Pos.1 are there redundant light sources for the shadowed light sources in position group Pos.4, while in the remaining position groups, there are no redundant light sources for the shadowed light sources in position group Pos.4. If the light sources in the two position groups Pos.2 and Pos.5 are configured as shown in Figure 5, then for each light source in position group Pos.2, there is a redundant light source in position group Pos.5, and vice versa.

[0178] The control device 10 can drive the m redundant light sources y.1, ..., ym so that the m driven light sources y.1, ..., ym together achieve a maximum individual illuminance greater than before. However, this step compensates for the shadowing of the light source x only if the sum of the increased current maximum individual illuminances of the m light sources y.1, ..., ym is as large as the sum of the current maximum individual illuminances of the m+1 light sources x and y.1, ..., ym before the shadowing. This is often not possible, especially when multiple light sources are simultaneously shadowed and / or when some of the m non-shadowed redundant light sources y.1, ..., ym have already achieved their respective maximum individual illuminances before the shadowing and therefore cannot be further increased. The maximum possible individual illuminance that a light source can achieve is limited, in particular, by the maximum current intensity that can flow through this light source.

[0179] If the shadowed light source cannot be compensated for or cannot be fully compensated for by at least one redundant and non-shadowed light source, the control device 10 searches for at least one other light source in the following stepwise manner to compensate for the shadowing and in so doing respect the three objectives listed above in the order of priority listed therein: If one step results in full or at least sufficient compensation of the shadowing, the next step is not executed.

[0180] As a first step, the control device 10 searches for light sources that are partially redundant for the light source for which the shadow is being cast. Two different sets of positions are partially redundant if they both generate the same light field, but each light source in one set of positions is not redundant for each light source in the other set of positions. Examples of redundant and only partially redundant light sources are shown in Figures 6 and 7. Two sets of positions Pos.2 and Pos.5 generate the same light field (see Figure 8). However, for a light source in set of positions Pos.2, there is no redundant light source in set of positions Pos.5, and vice versa.

[0181] In the situations of Figures 6 and 7, if a light source in position group Pos.2 is shadowed, the control device 10 searches for light sources in position group Pos.2 or Pos.5 that are partially redundant to the shadowed light source and that are not themselves shadowed. For example, if light source a.2 is shadowed, the control device 10 finds two light sources b.2 and f.2 in position group Pos.2 and two light sources a.5 and b.5 in position group Pos.5. The control device 10 searches for at least one light source that is not itself shadowed and that is not already operating at its maximum individual illuminance. If the control device 10 finds such a light source, the control device 10 increases the maximum individual illuminance of this light source to the maximum possible individual illuminance. If the control device 10 finds multiple such light sources, the maximum individual illuminance of all of these light sources is preferably increased.

[0182] The second step is performed if the previous steps did not result in sufficient compensation of the shadow formation. In the second step, the control device 10 searches for a light source y that cumulatively satisfies the following characteristics: · Light source y belongs to the same location group as light source x, whose shadow is being cast. No shadow is cast on the light source y. Light source y is not currently operating at its maximum possible individual illuminance.

[0183] If this precondition is met, the control device 10 increases the maximum individual illuminance of the light source y, preferably up to the maximum possible individual illuminance.

[0184] If this also does not provide sufficient compensation for shadow formation, the control device 10 executes a third step in which it searches for a light source y that cumulatively satisfies the following characteristics: · Light source y belongs to a set of positions that are partially redundant with the set of positions of light source x where a shadow is being cast. No shadow is cast on the light source y. Light source y is not currently operating at its maximum possible individual illuminance.

[0185] Here too, the control device 10 increases the maximum individual illuminance of this light source y.

[0186] If the third step does not result in sufficient compensation for the shadow formation, the control device 10 selects a light source that is not currently shadowed and that belongs to a further group of positions, for example a group of positions adjacent to the group of positions of the shadowed light source, and the control device 10 increases the maximum individual illuminance of at least one of the selected light sources. [Explanation of symbols]

[0187] 5 Grips provided on the support 8, allowing the lighting device 100 to be moved and oriented in space 8. Support of the lighting device 100, supporting the light sources a.1, ..., a.6, b.1, ..., b.6, ..., the grip 5 and the distance measuring devices dm, dm.1, ..., dm.6 10. A control unit for receiving signals from the distance measuring devices dm, dm.2, ..., dm.6 and using these signals as signals for the distance measuring assembly, for controlling and driving the light sources a.1, ..., a.6, b.1, ..., b.6, ... of the lighting device 100, and for processing the signals, which has at least temporary read access to the data memories 11 and 12 and write access to the data memory 12. 11 Data memory containing invariant information about light sources a.1,...,a.6,b.1,...,b.6,... 12 Data memory in which variable information about light sources a.1, ..., a.6, b.1, ..., b.6, ... is stored 20. An input unit that allows the user to vary the maximum overall illuminance, light field diameter, and correlated color temperature. 100 Illumination device including light sources a.1, ..., a.6, b.1, ..., b.6, ..., a support 8, a grip 5, an input unit 20, a control device 10, and distance measuring devices dm, dm.2, ..., dm.6, which is rotationally symmetrical with respect to an optical central axis MA a.1, ..., a.6, b.1, ..., b.6, ... Individual light sources of the lighting device 100 AO Shadow-Casting Objects Bg.a, ...Bg.e: groups of lighting devices 100 each including eleven light sources a.1, ..., a.6, b.1, ..., b.6, ... dm A central distance measuring device that measures the distance between the lighting device 100 and the object being illuminated along the central axis MA. dm.x Distance measuring instrument for position group Pos.x (x=2,…,6) LA a.4 Optical axis of light source a.4 LA d.2 Optical axis of light source d.2 Lf.1 Light field generated jointly by light sources in position group Pos.1 Lf.2 Light field generated jointly by light sources in position group Pos.2 Lf a.4 Circular light field of source a.4 on illuminated surface Ob Lf d.2 Circular light field of source d.2 on illuminated surface Ob Lk a.4 Light cone of light source a.4 Lk d.2 Light cone of light source d.2 MA Optical central axis of the illumination device 100 Ob - the illuminated surface of the object Obj facing the illumination device 100 Obj the illuminated object, here: a patient on an operating table whose surface Ob facing the illumination device 100 is illuminated by the illumination device 100 Pos.1: a group of positions of the lighting device 100 including light sources a.1, b.1, ..., f.1 Pos.2, ..., Pos.6: Further positions of the lighting device 100, which comprise light sources a.2, ..., f.2 or a.3, ..., f.3 or ... and respectively at least one distance measuring device dm.2 or dm.3 or ... r the corresponding distance on the illuminated surface between the central axis MA and the optical axes of the light sources of the position groups Pos.2 and Pos.5 r1 central axis MA and the optical axis LA of the light source of position group Pos.3 a.3 and L.A. d.3 The distance between the illuminated surface Ob and r2 central axis MA and the optical axis LA of the light source of position group Pos.6 a.6 and L.A. d.6 The distance between the illuminated surface Ob and S: Intersection of the optical central axis MA and the illuminated surface Ob S.1 Optical axis LA a.5 and L.A. a.2 and the common intersection of the illuminated surface Ob S.2 Optical axis LA d.5 and L.A. d.2 and the common intersection of the illuminated surface Ob

Claims

1. An illumination device (100) for illuminating a surface (Ob), comprising: The lighting device (100) comprises: a light source set comprising a plurality of light sources (a.1, a.2, ..., b.1, b.2, ...); a distance measuring assembly comprising a plurality of spaced apart distance measuring devices (dm, dm.2, dm.3, ...); a control device (10) for processing the signals; It contains The lighting device (100) comprises: - has an optical center axis (MA), configured to achieve a maximum overall illuminance over a maximum area on the illuminated surface (Ob); Each light source (a.1, a.2, ..., b.1, b.2, ...) of the light source set has ・Optical axis line (Lf ａ．１ , Lf ａ．２ , ...) are configured to generate a respective light field on the illuminated surface (Ob), each light source (a.1, a.2, ..., b.1, b.2, ...) has a maximum possible individual illuminance of the generated light field, the maximum individual illuminances of the light sources (a.1, a.2, ..., b.1, b.2, ...) of the light source set are adjustable to a value between zero and the maximum possible individual illuminance of the light sources (a.1, a.2, ..., b.1, b.2, ...) independently of the respective maximum individual illuminances of the other light sources, the control device (10) is configured to detect predetermined information for each light source (a.1, a.2, ..., b.1, b.2, ...) of the light source set, The detected or detectable information may be the following information: what the maximum possible individual illuminances the light sources (a.1, a.2, ..., b.1, b.2, ...) can generate; the optical axes (Lf) of the light sources (a.1, a.2, ..., b.1, b.2, ...) ａ．１ , Lf ａ．２ , ...) are positioned and / or oriented relative to the central optical axis (MA) of the lighting device (100); It contains Each distance measurer (dm, dm.2, ..., dm.6) of the distance measurement assembly is has a measurement direction pointing towards said illuminated surface (Ob), It is configured to measure a measure for each distance between itself and a light scattering object (Ob, AO), the control device (10) is configured to adjust each current maximum individual illuminance of each light source (a.1, a.2, ..., b.1, b.2, ...) of the light source set to a value, The control device (10) is further configured to detect an illuminance setting, the illuminance setting predefining a target value for the maximum overall illuminance to be generated by the lighting device (100); The control device (10) controls, in relation to the signal of the distance measuring assembly, - configured to check for the occurrence of a shadow formation event, which is the presence of at least one object (AO) between the lighting device (100) and the illuminated surface (Ob); configured to determine, after detection of a shadow-forming event, a shadow-forming region, which is at least approximately a region on the illuminated surface (Ob) that is completely or at least partially shadowed by the object (AO); and searching for at least one light source of the set of light sources that is suitable for shadow compensation in relation to the determined shadow-forming region; Light sources suitable for shadow compensation are: light sources (a.1, a.2, ..., b.1, b.2, ...) currently operating with a value for said maximum individual illuminance that is lower than said maximum possible individual illuminance of said light sources, - no shadows at all, or at least not completely shadowed light sources (a.1, a.2, ..., b.1, b2, ...), and ・Optical axis line (Lf ａ．１ , Lf ａ．２ , ...) are light sources (a.1, a.2, ..., b.1, b.2, ...) intersecting with the illuminated surface (Ob) in the determined shadow-forming area. and The control device (10) further comprises, if at least one light source suitable for shadow formation compensation is found, in relation to the detected illuminance settings and information about the detected or detectable light sources (a.1, a.2, ..., b.1, b.2, ...) of the light source set, configured to determine a subset comprising at least one suitable light source; configured to calculate, for each light source of the selected subset, a respective target value for the maximum individual illuminance of the light source, the target value being greater than a current value of the maximum individual illuminance of the light source; configured to cause the light source to actually currently achieve the calculated target value for the maximum individual illuminance, Two objectives when calculating the target values ​​for the maximum individual illuminance of the light sources of the subset are: the position of the maximum area relative to the central optical axis (MA) remains unchanged; the actual value of the maximum overall illuminance currently achieved by the lighting device (100) in the maximum area is equal to the detected illuminance setting; and The control device (10) After detecting the illumination setting and optionally the light field diameter setting, for each light source (a.1, a.2, ..., b.1, b.2, ...) of the light source set, one initial target value is calculated for the current maximum individual illuminance of the light source (a.1, a.2, ..., b.1, b.2, ...), is configured to equalize each actual value of the maximum individual illuminance achieved by a light source (a.1, a.2, ..., b.1, b.2, ...) of the light source set with the calculated initial target value for the light source (a.1, a.2, ..., b.1, b.2, ...), the initial target value is used at least as long as no shadow-forming event is detected and no further illumination setting is detected; The control device (10) is further configured to execute an increase sequence at least once after detecting a shadow formation event and after finding a suitable light source; The or each increase sequence is configured such that the control device (10) - determining a subset of said set of light sources comprising at least one light source suitable for shadow formation compensation; - calculating a target value for the maximum individual illuminance of the or each light source of the determined subset, the target value being greater than the current maximum individual illuminance; - increasing the current maximum individual illuminance of the or each light source of the determined subset to the calculated target value; Contains, A lighting device (100).

2. for each detected or detectable light source (a.1, a.2, ..., b.1, b.2, ...) of the set of light sources, the information about the light source comprises a light field diameter of the light field generated by the light source; the control device (10) is further additionally configured to detect a light field diameter setting that predetermines a target value for the light field diameter that the light field generated by the lighting device (100) should have, the control device (10) is further configured to calculate the target value for the current maximum individual illuminance of the light sources of the subset with the further objective that the actual value of the light field diameter of the light field achieved by the lighting device (100) is equal to the detected light field diameter setting. characterized in that The lighting device (100) of claim 1.

3. The control device (10) further comprises: During execution of at least one growth sequence, during execution of each growth sequence, After the steps of determining the subset, calculating each of the target values, and increasing each of the current maximum individual illuminances, now configured to check by calculation whether the actual current value of the maximum overall illuminance of the lighting device (100) exactly corresponds to the detected illuminance setting, If not, A new subset is determined, and a target value for the maximum individual illuminance of each light source of the determined subset is calculated. It is configured as follows: characterized in that The lighting device (100) of claim 1.

4. the control device (10) is configured to detect at least one light source of the set of light sources as being fully shadowed or at least partially shadowed after detecting a shadow formation event; The control device (10) further includes, when searching for a light source suitable for shadow formation compensation: using information about the detected or detectable light sources of the set of light sources, and configured to search for at least one light source that satisfies at least one predetermined compensation criterion with respect to the shadowed light source or at least one shadowed light source; If at least one light source is found that satisfies the compensation criterion or at least one compensation criterion, configured to check which of the found light sources is suitable for shadow formation compensation, respectively; If at least one suitable light source is found that meets the compensation criteria, configured to determine and use a subset of light sources that satisfy the compensation criterion or at least one compensation criterion and are suitable for shadow formation compensation; characterized in that The lighting device (100) of claim 1.

5. The light source set of the lighting device (100) comprises: at least one first light source and at least one further light source redundant to said first light source; and / or At least one second light source and at least one other light source that is partially redundant to said second light source It contains if the two intersections of the illuminated flat surface (Ob) and the two optical axes of the two light sources are not spaced apart from each other by more than a predetermined tolerance, and if the two light fields achieved by the two light sources, respectively, do not deviate from each other by more than a predetermined tolerance, the other light source is redundant to the first light source; if the two intersections of the illuminated flat surface (Ob) and the two optical axes of the two light sources are not spaced apart from each other by more than a predetermined tolerance, or - if the two light fields achieved by the two light sources, respectively, do not deviate from each other by more than a predetermined tolerance, or The intersection of the optical axes of one of the light sources is d around the intersection of the optical axes of the other light source. ｘ If the x-axis is located on a circle and x is a predetermined percentage, the other light source is partially redundant to the second light source; for each detected or detectable light source of the light source set, the information about the light source includes information about which other light source or other light sources of the light source set are redundant or partially redundant to the light source, the control device (10) is configured to use as the or a compensation criterion that a further light source is redundant or partially redundant for the or a shadowed light source, characterized in that The lighting device (100) of claim 4.

6. The lighting device includes: at least one first light source; at least one second light source; at least one first further light source redundant to said first light source; at least one second further light source that is partially redundant to the second light source and not redundant to the first light source; It contains The control device (10) is configured to execute a first boost sequence; The first increasing sequence comprises: - searching for, for each shadowed light source, at least one other light source that is redundant or partially redundant to the shadowed light source and that additionally satisfies at least one predetermined additional criterion and is suitable for shadowing compensation; If at least one suitable redundant light source is found, increasing the actual value of the maximum individual irradiance of the suitable redundant light source or of the at least one suitable redundant light source; It contains The control device (10) based on the boosting performed during the first boosting sequence, configured to check whether the actual maximum overall illuminance value of the lighting device (100) is consistent with the detected illuminance setting; Optionally additionally configured to check whether the light field diameter value is consistent with the detected light field diameter setting; otherwise configured to execute at least one second boost sequence; The or at least one second boost sequence comprises: searching for, for each shadowed light source, one other light source that is redundant or partially redundant to the shadowed light source and that is suitable for shadow compensation and that does not satisfy the at least one predetermined additional criterion; Contains, characterized in that The lighting device (100) of claim 5.

7. In the first increasing sequence, the other light source is redundant with respect to the light source on which the shadow is formed. characterized in that The lighting device (100) of claim 6.

8. the light sources (a.1, a.2, ..., b.1, b.2, ...) of the light source set are divided into at least two light source groups (Pos.1, ..., Pos.6) such that each light source (a.1, a.2, ..., b.1, b.2, ...) of the light source set belongs to exactly one light source group (Pos.1, ..., Pos.6), characterized in that The lighting device (100) of claim 6.

9. The control device (10) - configured to select at least one further light source of the set of light sources, the further light source being suitable for shadow formation compensation, and to increase the maximum individual illuminance of the light sources; characterized in that The lighting device (100) of claim 6.

10. the light sources (a.1, a.2, ..., b.1, b.2, ...) of the light source set are divided into at least two light source groups (Pos.1, ..., Pos.6) such that each light source (a.1, a.2, ..., b.1, b.2, ...) of the light source set belongs to exactly one light source group (Pos.1, ..., Pos.6), the light sources of the light source group together generate at least one light field on the illuminated surface (Ob) when no shadow-forming event occurs; the maximum illuminance of the light field occurs at the intersection (S) of the central optical axis (MA) with the illuminated surface (Ob) or on a circle centered at the intersection (S), for each light source of the light source set, the detectable information about the light source includes information about which light source of the light source set belongs to which light source group; the control device (10) is configured to use as the or a compensation criterion that the further light source belongs to the same light source group as the or a shadowed light source, characterized in that The lighting device (100) of claim 6.

11. each light source of the lighting device (100) has one correlated color temperature, and the light sources (a.1, a.2, ..., b.1, b.2, ...) of the light source set collectively have at least two different color temperatures; For each detected or detectable light source of the set of light sources, the information about the light source includes a correlated color temperature of the light source; the control device (10) is configured to use as the or a compensation criterion that the further light source has the same color temperature as the or a light source in which a shadow is formed, characterized in that The lighting device (100) of claim 6.

12. The control device (10) automatically configured to detect the event that at least one light source of the set of light sources has failed; configured to compensate for the failure of the or each failing light source by means of shadow formation compensation; characterized in that The lighting device (100) of claim 1.

13. A method of illuminating a surface (Ob) using an illumination device (100), the illumination device (100) comprising: a light source set comprising a plurality of light sources (a.1, a.2, ..., b.1, b.2, ...); a distance measuring assembly comprising a plurality of spaced apart distance measuring devices (dm, dm.2, ..., dm.6); a control device (10) for processing the signals; It contains The illumination device (100) has a central optical axis (MA), Each light source (a.1, a.2, ..., b.1, b.2, ...) of the light source set has ・Optical axis line (Lf ａ．１ , Lf ａ．２ , ...) are configured to generate a respective light field on said illuminated surface (Ob), each light source (a.1, a.2, ..., b.1, b.2, ...) has a maximum possible individual illuminance of the generated light field, the current maximum individual illuminance of the light sources (a.1, a.2, ..., b.1, b.2, ...) of the light source set is adjustable to a value between zero and the maximum possible individual illuminance of the light sources (a.1, a.2, ..., b.1, b.2, ...) independently of the respective maximum individual illuminances of the other light sources, each distance measurer (dm, dm.2, ..., dm.6) of said distance measurement assembly has a measurement direction facing said illuminated surface (Ob); The illumination method comprises the following steps: the control device (10) detects predetermined information for each light source (a.1, a.2, ..., b.1, b.2, ...) of the light source set, The detected information includes the following information: what the maximum possible individual illuminances the light sources (a.1, a.2, ..., b.1, b.2, ...) can generate, and the optical axes (Lf) of the light sources (a.1, a.2, ..., b.1, b.2, ...) ａ．１ , Lf ａ．２ , ...) are positioned and / or oriented relative to the central optical axis (MA) of the lighting device (100); It contains The control device (10) detects an illuminance setting, the illuminance setting predefining a target value for a maximum overall illuminance that the lighting device (100) should generate; said control device (10) adjusts at least once to a value each current maximum individual illuminance of each light source (a.1, a.2, ..., b.1, b.2, ...) of said light source set; the lighting device (100) achieves a maximum overall illuminance over a maximum area on the illuminated surface (Ob); each distance measurer (dm, dm.2, ..., dm.6) of said distance measuring assembly measures a measure for each distance between itself and a light scattering object (Ob, AO) at least once; The control device (10) at least once - checking whether a shadow formation event has occurred, which is the presence of at least one object (AO) between the lighting device (100) and the illuminated surface (Ob); - using a signal of the distance measuring assembly for said inspection; The control device (10) triggers the following further steps after detecting a shadow formation event: the control device (10) determines a shadowed area, which is an area on the illuminated surface (Ob) that is completely or at least approximately shadowed by the object (AO), The control device (10) searches for at least one light source of the light source set that is suitable for shadow formation compensation in relation to the determined shadow formation area; Light sources suitable for shadow compensation are: light sources (a.1, a.2, ..., b.1, b.2, ...) currently operating with a value for said maximum individual illuminance that is lower than said maximum possible individual illuminance of said light sources, - no shadows at all, or at least not completely shadowed light sources (a.1, a.2, ..., b.1, b.2, ...), and ・Optical axis line (Lf ａ．１ , Lf ａ．２ , ...) are light sources (a.1, a.2, ..., b.1, b.2, ...) intersecting with the illuminated surface (Ob) in the determined shadow-forming area. and If the control device (10) finds at least one light source suitable for shadow formation compensation, The control device (10) - determining a subset comprising at least one suitable light source; - calculating for each light source of the selected subset a respective target value for the maximum individual illuminance of the light source, the target value being greater than the current value of the maximum individual illuminance of the light source; - causing the light source to actually currently achieve the calculated target value for the maximum individual illuminance; Run Two objectives when calculating the target values ​​for the maximum individual illuminance of the light sources of the subset are: the position of the maximum area relative to the central optical axis (MA) remains unchanged; the actual value of the maximum overall illuminance currently achieved by the lighting device (100) is equal to the detected illuminance setting; and The control device (10) After detecting the illumination setting and optionally the light field diameter setting, for each light source (a.1, a.2, ..., b.1, b.2, ...) of the light source set, one initial target value is calculated for the current maximum individual illuminance of the light source (a.1, a.2, ..., b.1, b.2, ...), is configured to equalize each actual value of the maximum individual illuminance achieved by a light source (a.1, a.2, ..., b.1, b.2, ...) of the light source set with the calculated initial target value for the light source (a.1, a.2, ..., b.1, b.2, ...), the initial target value is used at least as long as no shadow-forming event is detected and no further illumination setting is detected; The control device (10) is further configured to execute an increase sequence at least once after detecting a shadow formation event and after finding a suitable light source; The or each increase sequence is configured such that the control device (10) - determining a subset of said set of light sources comprising at least one light source suitable for shadow formation compensation; - calculating a target value for the maximum individual illuminance of the or each light source of the determined subset, the target value being greater than the current maximum individual illuminance; - increasing the current maximum individual illuminance of the or each light source of the determined subset to the calculated target value; Contains, lighting method.

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