Luminaire with light exit window

Abstract

A luminaire (100) comprising at least one light source (110) arranged to emit light source light (120), a light exit window (130) through which the emitted light is arranged to exit the luminaire as luminaire light (135), where the light exit window is configured to influence a brightness L of the light source light, the light exit window is configured to generate a distribution of brightness LP of the illuminator light as a function of a length 5 dimension x of the light exit window defined from a center (310) of the light exit window to a perimeter (320) of the light exit window.

Description

Technical Field

[0001] The present invention generally relates to a luminaire. More specifically, the present invention relates to a luminaire having a light exit window for influencing the light output from the luminaire. Background Art

[0002] There are many lighting arrangements (such as lamps, luminaires, etc.) in the prior art that include one or more features for influencing the light output from these lighting arrangements. It will be appreciated that lighting comfort is an important quality aspect of any lighting device or luminaire. In order to avoid discomfort glare, it is desirable that the brightness of the luminaire remain below a given limit or threshold. This may mean that the light intensity should be kept relatively low in certain directions, however, this may have one or more negative effects, such as increased cost of beam shaping components, reduced efficiency and / or the need for a greater number of luminaires to evenly illuminate the same area. Alternatively, if reduced luminous intensity is not an option, the luminous area may be made relatively large. However, this alternative may also be associated with one or more negative consequences, such as increased costs in terms of material usage and / or transportation of the luminaire.

[0003] It is therefore an object of the present invention to provide a lighting arrangement which is able to reduce discomfort glare from the lighting arrangement without reducing its average brightness during operation. Summary of the invention

[0004] It is of interest to overcome at least some of the deficiencies or disadvantages of current lighting arrangements in order to provide a lighting arrangement having an improved light output with reduced discomfort glare while maintaining average brightness during operation.

[0005] This and other objects are achieved by providing a luminaire having the features of the independent claim.Preferred embodiments are defined in the dependent claims.

[0006] Therefore, according to the present invention, a luminaire is provided, comprising at least one light source arranged to emit source light and a light exit window, wherein the source light is arranged to leave the luminaire through the light exit window as luminaire light. The light exit window is configured to influence or change the brightness L of the source light so as to generate a brightness L of the luminaire light as a function of a length dimension x of the light exit window defined from a center of the light exit window to a periphery of the light exit window. P The distribution of brightness L P The distribution of at least includes: a first interval x of length dimension x 1 , the first interval x 1 Including having a first gradient G 1 Brightness L P The step function S(x), G1 =dL P / dx; the second interval x of length dimension x 2 , the second interval x 2 With the first interval x 1 are arranged adjacent to each other, wherein the second interval x 2 Including brightness L P The function F(x), the brightness L P The function F(x) has a second gradient G 2 , G 2 =dL P / dx; and a third interval x of length dimension x 3 , the third interval x 3 With the first interval x 1 and the second interval x 2 The third interval x is arranged adjacent to one of 3 Including the brightness L P The nominal level L n (x), the brightness L P The nominal level L n (x) has a third gradient G 3 , G 3 =dL P / dx, where one of the following relations is satisfied: sgn(G 1 )=-1,sgn(G 2 )=+1, and |G 1 |>G 2 >|G 3 |; and sgn(G 1 )=+1,sgn(G 2 )=-1, and G 1 >|G 2 |>|G 3 |.

[0007] Therefore, the present invention is based on the concept of a luminaire which, via its light exit window, is able to provide a brightness with an edge pattern, so that one or more parts of the light exit window can appear brighter, while one or more parts of the light exit window can appear darker. This effect is also known or referred to as the Craik-O'Brien-Cornsweet illusion (hereinafter referred to as the Cornsweet illusion). By means of the features of the luminaire of the present invention, a reduced overall glare can be provided during operation of the luminaire. For example, when the brightness L P The distribution of the light exit window includes a brightness L ranging from a first brightness L to a second brightness L in a direction from the center of the light exit window to the periphery of the light exit window. 1 Through the step function S(x) of brightness (the step function S(x) of brightness includes the maximum step brightness L smaxand minimum step brightness L smin At least one of the above) changes to a second brightness L 2 When L 1 , L 2 >L smin And L 1 , L 2 <L smax Preferably, L 1 >L 2 , i.e., the center of the light exit window has a higher brightness than the periphery of the light exit window, which is preferably applicable to the case of outdoor luminaires (such as luminaires for street lighting). Therefore, the step function S(x) may include a step change in brightness, which step change in brightness includes a maximum value and / or a minimum value of the brightness. The step function S(x) in brightness includes a maximum step brightness L smax , and the minimum step brightness L smin In the case of 1 , L 2 , L smin and L smax The sequence from the center of the light exit window to the periphery is L 1 -L smin -L smax -L 2 or L 1 -L smax -L smin -L 2 , where L smax >L 1 , L 2 >L smin . Preferably, 1.4*L smin >L 1 , L 2 >1.2*L smin , and 1.2*L 1 , L 2 <L smax <1.4*L 1 , L 2 Brightness is usually measured in cd / m 2 In addition, preferably, the step function S(x) has a distribution width in the range of about 0.5° to about 10°, the distribution width being defined by the angular range of the distribution as seen by an observer at a given distance.

[0008] The present invention is advantageous in that the luminaire can suppress glare while maintaining the light intensity of the luminaire light from the luminaire. In other words, while prior art arrangements may require reducing the luminous intensity in order to reduce glare, which may result in increased cost of beam shaping components, reduced efficiency and / or the need for a greater number of luminaires to uniformly illuminate the same area, the luminaire of the present invention achieves efficiency in relation to cost and / or lighting characteristics.

[0009] A further advantage of the present invention is that the luminaire provides a convenient arrangement to reduce glare. For example, since prior art arrangements may require increasing the light emitting area in an attempt to avoid glare, this may result in increased material usage and / or shipping costs for the luminaire. In contrast, the luminaire of the present invention provides convenience with respect to size, cost and / or operation.

[0010] The luminaire of the present invention comprises at least one light source arranged to emit source light. "Luminaire" herein refers to substantially any luminaire, lighting arrangement, lighting device, etc. The light source may be substantially any light source, such as one or more light emitting diodes (LEDs). The luminaire comprises a light exit window, wherein the source light is arranged to leave the luminaire through the light exit window as luminaire light. The light exit window is configured to influence or change the brightness L of the source light for generating a brightness L of the luminaire light as a function of a length dimension x of the light exit window. P The distribution of the length dimension x of the luminaire light is defined as the length dimension from the center of the light exit window to the periphery of the light exit window, for example, in the case of a circular light exit window, the length dimension x of the light exit window is the radius of the light exit window. In other words, the light exit window is arranged or configured to influence or affect the light source light so as to generate a brightness L of the luminaire light as a function of the radius of the light exit window. P In other words, the light exit window of the illuminator is configured to map the brightness L of the light source light to a (two-dimensional) brightness distribution L P Brightness L P The distribution includes at least a first interval x of length dimension x 1 , the first interval x 1 Including brightness L P The step function S(x) of the brightness L P The step function S(x) has a first gradient G 1 , G 1 =dL P / dx. The term "step function S(x)" here refers to a function of the length dimension x that represents a (very) sudden increase or decrease. Thus, the first gradient G 1 =dL P= / dx is quite (or very) high (if positive) or quite (or very) low (if negative). Note that a (very) abrupt increase / decrease may not be visible to an observer at some distance from the luminaire (e.g. 2-6 m for indoor lighting and 10-30 m for street lighting). P The distribution also includes the first interval x 1 The second interval x of the length dimension x of the adjacent arrangement 2 , where the second interval x 2 Including having a second gradient G 2 =dL P / dx brightness L P Here, “adjacent arrangement” refers to the second interval x of the length dimension x. 2 Can be adjacent to the first interval x 1 Arrange or set, or alternatively, arrange in the first interval x 1 Brightness L P The distribution also includes the first interval x 1 and the second interval x 2 The third interval x of the length dimension x of an adjacent arrangement 3 , the third interval includes a third gradient G 3 =dL P / dx brightness L P The nominal level L n (x). It will be appreciated that the brightness L P The nominal level L n (x) is preferably constant, and the third gradient G 3 =dL P / dx is correspondingly (very) small, such as zero or almost zero. "Adjacently arranged" here means the third interval x of the length dimension x. 3 Can be adjacent to the first interval x 1 Or the second interval x 2 Arrange or set, or alternatively, arrange in the first interval x 1 Or the second interval x 2 Nearby. Satisfies one of the following relations: sgn(G 1 )=-1,sgn(G 2 )=+1, and |G 1 |>G 2 >|G 3 |; and sgn(G 1 )=+1,sgn(G 2 )==-1, and G 1 >|G 2 |>|G 3|. "sgn" here refers to the mathematical operator "sign", which can be positive (+1) or negative (-1). Therefore, sgn(G 1 )=-1,sgn(G 2 )=+1, and |G 1 |>G 2 >|G 3 |, or satisfy sgn(G 1 )=+1,sgn(G 2 )==-1, and G 1 >|G 2 |>|G 3 |. Studies have shown that the brightness L P The preferred distribution for the second interval x 2 is concave, which means that near the first interval x 1 The second interval x 2 The relatively steep gradient at and near the third interval x 3 A (very) small, or almost zero, gradient.

[0011] According to an embodiment of the present invention, the light exit window may include a pattern configured to influence or change the brightness L of the light source light. The term "pattern" herein refers to a pattern of the light exit window implemented and / or provided by substantially any suitable material (e.g., coating) and / or technology (e.g., etching). Thus, the pattern influences and / or dominates the light source light from the light source so as to achieve an influence on the brightness L of the light source light and is used to generate the brightness L of the illuminator light. P The advantage of this embodiment is that the setting of the pattern of the light exit window is convenient in terms of the influence of the light exit window of brightness L on the light source light. A further advantage of this embodiment is that the light exit window can be replaced by another light exit window including another pattern for customized operation of the luminaire.

[0012] According to an embodiment of the invention, the pattern is defined by the distribution of variable light transmittance of the light exit window along its length dimension x. The term "variable light transmittance" here means that the pattern is arranged or configured to provide at least a first light transmittance at at least a first position or section of the light exit window along its length dimension x, and to provide at least a second light transmittance at at least a second position or section of the light exit window along its length dimension x, wherein the first light transmittance is different from the second light transmittance. This embodiment is advantageous because the variable light transmittance property of the pattern can contribute to making the brightness L of the illuminator light generated by the illuminator P Creating a more desired and / or customized profile.

[0013] According to an embodiment of the present invention, the pattern can be defined by the distribution of a variable texture along the length dimension x of the light exit window. The term "texture" refers here to the surface characteristics of the pattern. In addition, the term "variable texture" refers here to the fact that the pattern has at least a first texture at a first position or section of the light exit window along its length dimension x, and has at least a second texture at at least a second position or section of the light exit window along its length dimension x, wherein the first texture is different from the second texture. This embodiment is advantageous because the characteristics of the variable texture of the pattern can contribute to the brightness L of the illuminator light generated by the illuminator. P Creating a more desired and / or customized profile.

[0014] According to an embodiment of the present invention, the pattern can be formed by a light exit window having a corresponding reflectivity R i At least two parts P i Therefore, the pattern can be defined by the light exit window having a first reflectivity R 1 At least the first part P 1 and the light exit window has a first reflectivity R 2 At least the second part P 2 To define, where R 1 ≠R 2 .

[0015] According to one embodiment of the present invention, the light exit window may include at least one of a cover element and a foil including a pattern. Thus, the light exit window may include a cover element and / or a foil including a pattern, the pattern being configured to influence / modify the brightness L of the light source light. An advantage of this embodiment is that the pattern can be conveniently arranged on the light exit window. A further advantage of this embodiment is that the pattern can be replaced by replacing the cover element and / or a foil with another pattern, thereby producing a more versatile luminaire in relation to the customized operation of the luminaire.

[0016] According to an embodiment of the present invention, the function F(x) includes at least one of an exponential function, a sine function, a cosine function, and a linear function. Therefore, the function F(x) may include any combination of an exponential function, a sine function / cosine function, and a linear function. It should be understood that many alternative functions and / or combinations of functions will be feasible. The advantage of this embodiment is that the function F(x) is monotonic (i.e., there is no sign change of the gradient) and smooth, and wherein the function F(x) is preferably in a range of 1 to 1. 1 The transition of has a sudden bend and has a transition to the third interval x 3 of smooth transition.

[0017] According to an embodiment of the invention, the light exit window may comprise an optical element configured for influencing / modifying the brightness L of the light source light and / or the illuminator light via beam shaping of said light. The term "optical element" herein refers to substantially any element arranged or configured to influence and / or govern the brightness L of the light source light and / or the illuminator light via beam shaping of said light.

[0018] According to an embodiment of the present invention, in which, associated with the direction DR of the length dimension x of the light exit window, the direction DR of the length dimension x is defined as from the center of the light exit window to the periphery of the light exit window, sgn(G 1 )=-1,sgn(G 2 )=+1, and |G 1 |>G 2 >|G 3 |, and wherein the first portion of the light exit window defined around its center has at least one first radial dimension Ra, the first radial dimension Ra comprising one of the following: a second interval x 2 and the third interval x 3 (on the one hand), and the third interval x 3 (On the other hand). It should be noted that the term "radial dimension" may include: a radius (for a circular light exit window); and one or more length dimensions from a center point to an edge in case the light exit window is not circular in shape (e.g. rectangular or square). Thus, in the latter case, there may be a first radial dimension, which may span from the center to one or more edges. Alternatively, there may be a (primary) first radial dimension and a (secondary) first radial dimension, which has a different length compared to the (primary) first radial dimension.

[0019] According to an embodiment of the present invention, at least one first radial dimension Ra is composed of a first interval x 1 Defined, where the first interval x of the light exit window 1 Thus, the first (central) portion is completely bounded by the first interval x of the light exit window. 1 The advantage of this embodiment is that the first (central part) is not completely limited by the first interval x. 1 Or the first interval x 1 This results in a relatively strong glare reduction compared to the case where the light exit window is defined by a combination of boundaries (resulting in a less strong brightness illusion and thus a less strong glare reduction).

[0020] According to an embodiment of the present invention, the first portion has a first area A 1 , wherein the first area A 1 and the total area A of the light exit window.1 =A 1 / A, satisfying 0.03<R 1 <0.14. The advantage of this embodiment is that the bright areas are much smaller than the dark areas, so the overall brightness and glare are reduced compared to a uniform brightness distribution with the same average brightness.

[0021] According to an embodiment of the present invention, in which, associated with the direction DR of the length dimension x of the light exit window (the direction DR is defined as from the center of the light exit window to the periphery of the light exit window), sgn(G 1 )=+1,sgn(G 2 )=-1, and G 1 >|G 2 |>|G 3 |, and wherein the second portion of the light exit window defined around its center has at least one second radial dimension R b , the R b Include one of the following: On the one hand, the second interval x 2 and the third interval x 3 On the other hand, the third interval x 3 According to one example, at least one second radial dimension R b From the first interval x 1 Define, where the first interval x 1 At least one of the peripheries of the light exit window forms a closed loop.

[0022] According to an embodiment of the present invention, the second portion has a second area A 2 , where the second area A 2 A second ratio R between the total area A of the light exit window 2 =A 2 / A satisfies R 2 >0.86. An advantage of this embodiment is that the darker areas are significantly larger than the brighter areas, resulting in an overall reduction in glare.

[0023] According to an embodiment of the present invention, the first interval x of the length dimension x 1 Including brightness L P It has been found that the optimum peak brightness contrast at the edge is about 20%-30% (on each side), and if the Cornthwaite edge is double-sided (i.e., with a second interval x 2 , which is located in the first interval x 1 ), resulting in an optimal peak brightness contrast ratio of 40%-60%. Brightness L P The distribution in the direction from the center of its light exit window to the periphery of the light exit window may include a brightness L ranging from a first brightness L 1Via the step function S(x) of brightness to the second brightness L 2 The brightness step function S(x) includes the maximum step brightness L smax and minimum step brightness L smin At least one of which L 1 , L 2 >L smin And L 1 , L 2 <L smax In addition, preferably, L 1 >L 2 , that is, the center of the light exit window has a higher brightness than the brightness at the periphery of the light exit window, which is preferably applicable to the case of outdoor luminaires (such as luminaires for street lighting). Therefore, the step function S(x) may include a step change in brightness, which step change in brightness includes a maximum value and / or a minimum value of the brightness.

[0024] The step function S(x) of the brightness includes the maximum step brightness L smax and the minimum step brightness L smin In the case of 1 , L 2 , L smin and L smax The sequence from the center of the light exit window to the periphery is L 1 -L smin -L smax -L 2 or L 1 -L smax -L smin -L 2 , where L smax >L 1 , L 2 >L smin .

[0025] Typically, 1.4*L smin >L 1 , L 2 >1.2*L smin and 1.2*L 1 , L 2 <L smax <1.4*L 1 , L 2 Brightness in cd / m 2 express.

[0026] According to an embodiment of the present invention, the first interval x 1 and the second interval x 2 The sum S satisfies 1cm<S<16cm. Studies have shown that the brightness LP The optimal distribution width of is about 1° (defined by the angular range of the distribution seen by an observer at a given distance). Since the typical indoor lighting viewing distance is 3m, the first interval x of the light exit window 130 is 1 and the second interval x 2 The sum S (width) should be about tan (α = 1°) * 3m = 0.05m, i.e. 5cm. It should be noted that the first interval x 1 The length of the second interval x is much smaller than 2 In addition, the brightness L of about 1° P The optimal distribution width of is related to one (single) side of the pattern and is not related to the double-sided pattern (with a second interval x 2 , which is in the first interval x 1 In the case of ), it is correspondingly doubled, ie, about 2°.

[0027] Further objectives, features and advantages of the present invention will become apparent when studying the following detailed description, the drawings and the appended claims.Those skilled in the art will realize that different features of the present invention can be combined to produce embodiments other than those described in the following. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing embodiments of the invention.

[0029] Figure 1a Schematically shows a luminaire according to an embodiment of the present invention;

[0030] Figure 1b schematically shows the distribution of brightness produced by the illuminator;

[0031] Figure 2 Schematically shows a light exit window of a luminaire according to an embodiment of the present invention;

[0032] Figures 3a to 3f Schematically illustrates a luminaire according to an embodiment of the present invention and the distribution of brightness and luminous intensity generated by the luminaire;

[0033] Figure 4a to Figure 4b schematically illustrates a luminaire according to an embodiment of the present invention; and

[0034] Figure 5 The preferred length of the length dimension x of the light exit window of a luminaire according to an embodiment of the invention is schematically shown. DETAILED DESCRIPTION

[0035] Figure 1aA luminaire 100 according to an exemplary embodiment of the present invention is schematically shown. It should be noted that the size, dimensions, etc. of the luminaire 100 and its components are not drawn to scale. The luminaire 100 comprises at least one light source 110 arranged to emit light source light 120. The light source 110 may, for example, comprise one or more LEDs. The luminaire 100 further comprises a light exit window 130, which is arranged above the light source 110 relative to the axis A. The emitted light source light 120 from the light source 110 is arranged to leave the luminaire 100 through the light exit window 130 as luminaire light 135. It should be understood that the light exit window 130 may comprise substantially any material or any material composition that is light-transmissive. The light exit window 130 is configured to influence / modify the brightness L of the emitted light source light 120 to produce, for example, Figure 1b The brightness L of the illuminator light 135 described in P For example, the light exit window 130 may include a pattern 140 configured to influence the emitted light source light 120 from the light source 110 to produce a brightness L of the illuminator light 135 leaving the illuminator 100. P The pattern 140 can be generated by printing or coating a layer of reflective paint (preferably) or absorbing paint on the light exit window 130 of the luminaire 100. In the case of an edge-lit luminaire panel (not shown), the pattern 140 can also be present in the coupling-out features of the light guide (paint dots, facets, chemically etched or laser etched patches, etc.). Other solutions involve the pattern 140 in the thickness of the diffuser plate or foil, or in the shape of the beam shaping elements (lenses, micro-cones, micro-prisms) on the beam shaping optical plate. The pattern 140 is thus produced by local variations in the beam shape, meaning that the contrast can be reversed for different viewing directions: when the luminous intensity distribution varies locally, a higher light intensity in a given direction is typically compensated by a lower light intensity in another direction. The light exit window 130 can include a cover element and / or a foil 195 including the pattern 140, wherein the cover element / foil 195 is represented by a dotted line.

[0036] Generates the brightness L as a function of the length dimension x of the light exit window 130 P The distribution of the light exit window 130 , the length dimension being defined as from the center 310 of the light exit window 130 to the periphery 320 of the light exit window 130 .

[0037] Figure 1b The brightness L generated by the luminaire 100 and its light exit window 130 is schematically shown. P The distribution of the brightness has a step function S(x) of the brightness, and the step function S(x) of the brightness has a first brightness L at the center 310 of the light exit window 130. 1 and the second brightness L at the periphery 320 of the light exit window 130 2The maximum step brightness between smax and minimum step brightness L smin ,like Figure 1a and as described in the relevant text. Brightness L P The distribution includes at least a first interval x of length dimension x 1 , the first interval x 1 Including brightness L P The step function S(x) of the brightness L P The step function S(x) has a first gradient G 1 , G 1 =dL P / dx. Therefore, in the first interval x 1 At, brightness L P The brightness variation in the distribution of is significant. P The distribution also includes a second interval x of length size x 2 , the second interval x 2 With the first interval x 1 are arranged adjacently and indicated in the first interval x 1 On either side of . The second interval x 2 Including having a second gradient G 2 =dL P / dx brightness L P The function F(x). 2 ) can be any function that substantially corresponds to the indicated distribution, such as an exponential function, a sine / cosine function, a linear function, etc. P The brightness of the distribution in the first interval x 1 At (at a relatively high first gradient G 1 =dL P / dx) compared to the (significant) sudden change in brightness L P The second gradient of brightness in the distribution G 2 =dL P / dx in the second interval x 2 Brightness L P The distribution also includes a third interval x of length dimension x 3 , the third interval x 3 With the second interval x 2 are arranged adjacently and in the second interval x 2 The third interval x 3 Including brightness L P The nominal level L n (x), the brightness L P The nominal level L n (x) has a third gradient G 3 , G 3 =dLP / dx,G 3 is (very) small, for example (almost) zero. 1 、x 2 The brightness L at the first and second gradients is P The distribution of brightness changes compared to the nominal level L n (x) indicates relatively small or even non-existent brightness L P Therefore, preferably, in the third interval x 3 Inside, brightness L P However, it should be noted that Figure 1b As shown in 1 The brightness change on the second interval x 2 The brightness change on the same. The brightness L can be described mathematically P distribution, this is because the first condition (sgn(G 1 )=-1,sgn(G 2 )=+1, and |G 1 |>G 2 >|G 3 |) or satisfy the second condition (sgn(G 1 )=1,sgn(G 2 )=-1, and G 1 >|G 2 |>|G 3 |). Therefore, in Figure 1b In the left-to-right direction, the first condition applies because G 1 is negative (sgn(G 1 )=-1), that is, the brightness L P The brightness in the distribution of G decreases and its absolute value is relatively high. 2 is positive (sgn(G 2 )=+1), that is, the brightness L P The brightness in the distribution increases, satisfying the relationship |G 1 |>G 2 >|G 3 |. Alternatively, in the right-to-left direction, the second condition applies, where sgn(G 1 )=1,sgn(G 2 )=-1, and satisfies G 1 >|G 2 |>|G 3 |.

[0038] In other words, Figure 1b In the example, the brightness L generated by the luminaire 100 is PThe distribution includes relatively sudden steps S(x 1 ), and the brightness L P The second gradient G of the function F(x) 2 The second gradient G of the function F(x) is not so abrupt. 2 Specific brightness L P The nominal level L n The third gradient G of (x) 3 The luminaire 100 thus achieves reduced overall glare during operation of the luminaire 100 via the Cornthwaite illusion.

[0039] Figure 2 Schematically shows a light exit window 130 of a luminaire according to an embodiment of the present invention. Here, the light exit window 130 is illustrated as having a circular shape, but it should be noted that other shapes (eg rectangular) are also possible. Figure 1a Compared to the orientation of the luminaire 100 relative to the axis A, Figure 2 The light exit window 130 in is shown from above (as indicated by the axis A). Figure 2 , the light exit window 130 comprises a pattern 140 which is configured to influence / modify the brightness L of the light source light emitted from the light source of the luminaire. Figure 1a Similar to the schematically illustrated pattern 140, it should be noted that Figure 2 The form of the pattern 140 in FIG. 1 is (also) only shown for reasons of understanding, and the pattern 140 may have many different forms in order to influence the brightness L of the light source light to achieve the brightness L of the illuminator light. P The lines in pattern 140 indicate features in the brightness pattern, such as maximum values, minimum values, or transitions between intervals. Figure 2 The concentric circles of the pattern 140 in FIG. 1 are presented only as examples, and the pattern 140 may take many different forms and / or include many different features. The pattern 140 may be implemented, for example, by a coating. According to one or more other examples, the pattern 140 may be defined by a distribution of variable light transmittances of the light exit window 130 along its length dimension x and / or by a distribution of variable textures of the light exit window 130 along its length dimension x. In addition, the pattern 140 may be defined by at least two portions P of the light exit window 130. 1 , P 2 It is defined that the at least two parts have corresponding reflectivity R 1 , R 2 , where R 1 ≠R 2 It should be noted that Figure 2 The first and second parts of P 1 , P 2The form, placement, etc. of the light exit window 130 are merely exemplary and for the sake of understanding, and may differ from the Figure 2 The situations are different from those shown in .

[0040] and Figure 1a Similarly, the light exit window 130 may comprise a cover element and / or a foil 195 comprising the pattern 140. It should be noted that Figure 2 The cover element and / or foil 195 in FIG. 1 is indicated only for the sake of understanding why the cover element / foil 195 comprises the pattern 140. Furthermore, the light exit window 130 may comprise an optical element (not shown) which is configured to influence / modify the brightness L and / or L of the light source light and / or the illuminator light by shaping the beam of the light source light and / or the illuminator light. P .

[0041] Figures 3a to 3f A luminaire according to an embodiment of the present invention and the distribution of brightness and luminous intensity generated by the luminaire are schematically shown.

[0042] Figure 3a and Figure 3b A luminaire 100 according to an embodiment of the invention is schematically shown. Figure 3b The brightness L P The distribution and Figure 3a The illuminator 100 shown in FIG. Figure 3b The brightness L P The distribution corresponds to Figure 1b The distribution shown in Figure 3b Omit interval x 1 、x 2 、x 3 and functions S(x), F(x), Ln(x), and it refers to Figure 1b ).exist Figure 3b Medium, brightness L P The distribution includes at least a first interval x of length dimension x 1 , the first interval x 1 Including brightness L P The step function S(x) of the brightness L P The step function S(x) has a first gradient G 1 =dL P / dx. Brightness L P The distribution also includes the first interval x 1 The second interval x of the length dimension x of the adjacent arrangement 2 , where the second interval x 2 Including having a second gradient G 2 =dL P / dx brightness L PFunction F(x). Brightness L P The distribution also includes a third interval x of length dimension x 3 , the third interval and the second interval x 2 The second interval includes a third gradient G 3 =dL P / dx brightness L P The nominal level L n (x). Figure 3a As shown, associated with the direction DR of the length dimension x of the light exit window 130 defined from the center 310 of the light exit window 130 to the periphery 320 of the light exit window 130, the condition is satisfied: (sgn(G 1 )=-1,sgn(G 2 )=+1, and |G 1 |>G 2 >|G 3 |), such as Figure 3b The brightness L P The distribution of is shown. Figure 3b The brightness L P The distribution of creates a visual illusion of brightness steps, such as Figure 3c Schematically shown (not to scale). Thus, the brightness distribution will make the exit window appear as if one side has a higher "apparent" brightness and the opposite side has a lower "apparent" brightness, even though the actual brightness may be the same on both sides of the brightness distribution. Figure 3a As shown, the first (central) portion 300 of the light exit window 130 defined around its center has a first radius Ra (exemplified as Ra 1 ). The first portion 300 may include a second interval x 2 and the third interval x 3 ,like Figure 3a Ra 1 Therefore, the first radius Ra 1 The first interval x extends from the center of the light exit window 130 to the boundary (which can be 1 The first portion 300 may alternatively be defined by the border of the light exit window 130. Alternatively, the first portion 300 (only) comprises the third interval x 3 , as used by Figure 3f Ra of the single-sided Cornthwaite edge pattern shown 2 Therefore, in Figure 3f The first brightness L at the center of the light exit window 1 The second brightness L at the periphery of the light exit window 2 The brightness step function S(x) has only the minimum step brightness L smin .

[0043] exist Figure 3a , the luminaire 100 is divided into two regions: a central region A having an "apparent" brightness L1 = L + dL 1 and edge region A with an "apparent" brightness L2 = L-dL 2 , where, as an example, the relationship between dL and L may be dL = 0.2*L. It should be noted that the relationship between dL and L presents only one example, and that the relationship may vary significantly depending on the details of the distribution (shape, amplitude, width, observer position, etc.).

[0044] The Unified Glare Rating (UGR) is a measure of the glare in a given environment. More specifically, the UGR can be used to predict uncomfortable glare in interior applications and, in mathematical terms, is a function of the logarithm of the sum of all glare contributions from visible light sources in the field of view divided by the background luminance. The change in UGR can be achieved by dividing the two regions A by 1 , A 2 The contributions are determined by adding together, as if the two areas were two separate sources, where A is the total area:

[0045] δUGR=8log 10 (L 1 2 ·A 1 +L 2 2 ·A 2 ) / (L 2 ·A)=8log 10 (1+(dL / L) 2 +

[0046] 2·(dL / L)·((A 1 -A 2 ) / A))(Equation 1)

[0047] The only significant glare difference corresponds approximately to 1 UGR point. As a lower limit (δUGR = -1, where the negative sign arises due to the desired reduction in glare), the bright central area A 1 The relationship between the total area A and 1 = 0.14A, which in the case of an exemplary diameter of the light exit window of 60 cm may correspond to a circle with a diameter of 22 cm. The bright area may be even slightly smaller to have even more glare reduction, but for the example of a light exit window with a diameter of 60 cm, it may have a diameter of no less than 10 cm, since the Cornthwaite edge requires this minimum width. Therefore, if described mathematically, and according to Figure 3d In the example, the first portion 300 has a first area A 1 , where the first area A 1A first ratio R between the total area A of the light exit window 1 =A 1 / A, satisfying 0.03<R 1 <0.14. However, it should be noted that for other illuminator (light exit window) sizes and / or different observer distances, the bright central area A 1 Examples of dimensions of the and / or light exit windows may be different.

[0048] Figure 3d Included with Figure 3a The illuminator is different from the illuminator 100, and Figure 3d The associated brightness L P The distribution and Figure 3b The associated brightness L P The distribution of Figure 3a The luminaire 100 is associated with a direction DR of a length dimension x of the light exit window defined from a center 310 of the light exit window to a periphery 320 of the light exit window, by Figure 3e (exist Figure 3e Omit interval x 1 、x 2 、x 3 And the functions S(x), F(x), L n (x) and refers to Figure 1b ) brightness L P The distribution satisfies the following conditions: (sgn(G1)=+1, sgn(G 2 )=sgn(G 3 )=-1, and G1>|G 2 |>|G 3 |). In addition, Figure 3d As shown, the second portion 305 defined around the center of the light exit window 130 has a second radius Rb (exemplified as Rb 2 ). The second portion 305 may include a second interval x 2 and the third interval x 3 ,like Figure 3d Rb 2 As shown. Figure 3d In the embodiment, the edge coincides with the edge of the light exit window 130, and the area outside the light exit window 130 is the ceiling in which the luminaire 100 is placed. Figure 3d describes the case of a one-sided Cornthwaite pattern, where the first interval x 1 coincides with the boundary of the light exit window 130, wherein the (darker) second interval x 2 Inside, and the third interval x 3This embodiment reduces the brightness of the second (central) portion 305. In this case, there is no third interval x outside the second portion 305. 3 , because the second portion 305 fills the entire light exit window 130. The outer area (i.e. outside the light exit window 130) represents a (relatively) dark ceiling and results in a relatively dark (compared to the case without the Cornthwaite edge) second portion 305 that is still brighter than the ceiling.

[0049] According to the example, it may be desirable to make the central portion A c (not shown) as large as possible to reduce glare. c A second ratio R between the total area A of the light exit window 2 =A c / A, can satisfy R 2 >0.86. For the example of a light exit window 130 with a diameter of 60 cm, this may correspond to a circle with a diameter of 56 cm. It should be noted that this only leaves a 2 cm edge for the bright area. Since this is too small for a complete Cornthwaite pattern (preferably at least 5 cm is required for the bright part of the Cornthwaite edge), the contrast illusion may not be as strong.

[0050] Figure 4a to Figure 4b Schematically shows a luminaire 100 according to an embodiment of the present invention. Here, the light exit window 130 is rectangular (eg, square). Figure 4a In the embodiment, the central portion 300 of the light exit window 130 includes a second interval x 2 and the third interval x 3 , and the boundary of the central portion 300 is in the first interval x 1 At Figure 4a-4b The first, second and third intervals are not indicated and reference is made to Figure 1b ).exist Figure 4a In the first interval x 1 Thus a closed loop is formed. Figure 4a The radial dimensions R shown in a perpendicular relationship in FIG. have the same length. Figure 4b The luminaire 100 discloses a central portion 300, the boundary of which is in a first interval x 1 At and along Figure 4b The horizontal axis in is located inside the light exit window 130, and the first interval x 1 Along Figure 4b The vertical axis in is at the edge of the light exit window 130 . Figure 4a The radial dimension R shown in the vertical relationship 1 , R 2 have different lengths. Therefore, although Figure 4aThe central portion 300 of the light exit window 130 has a first interval x 1 The boundary defined by the first interval x 1 The first interval x is defined and partly defined by the boundary of the light exit window 130. 1 Or the first interval x 1 In the configuration defined by the combination of the first interval x and the border of the light exit window 130, the brightness illusion (and thus the glare reduction) produced by the brightness pattern is not too strong. 1 This undesirable situation may occur when a closed loop is not formed and ends somewhere inside the light exit window 130 .

[0051] Figure 5 The preferred length of the length dimension x of the light exit window 130 of the luminaire 100 is schematically shown. Studies have shown that the brightness L P The optimal distribution width of is about 1 degree, which corresponds to the optimal width of the second interval x 2 , because the width of the first interval x 1 As a typical indoor lighting viewing distance Ld (ie, the distance from the light exit window 130 / luminaire 100 to the user 155) is 3 m, the first interval x of the light exit window 130 is 1 and the second interval x 2 The sum S(width) should be approximately tan(α=1°)*3m=0.05m. The width should preferably be greater than α=0.5° (corresponding to 0.025m) and preferably not less than α=0.2° (corresponding to 0.01m). On the other hand, a width greater than α=1° will enhance the effect, but the enhancement becomes marginal above α=2-3°. Therefore, the width is preferably less than α=3° (corresponding to 0.16m), because in practice, a width greater than 3° is generally not suitable for most indoor luminaires (e.g., in indoor lighting, the standard luminaire size is generally about 0.6m x 0.6m). It should be noted that the spacing of the ceiling grid can be 60cm, which results in a slightly smaller luminaire, e.g., 0.58cm x 0.58cm. Larger luminaires can also be used, or alternatively, very slim luminaires can be used, e.g., 10cm x 120cm.

[0052] A person skilled in the art realizes that the present invention is by no means limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, the size and / or form of one or more components of the luminaire 100 (e.g., the light source 110, the light exit window 130, etc.), the brightness L P The form / distribution may be different from that shown, etc.

Claims

1. A lighting device (100), include: at least one light source (110) arranged to emit light source light (120), a light exit window (130), wherein the emitted light source light is arranged to leave the luminaire through the light exit window as luminaire light (135), The light exit window is configured to influence or modify the brightness L of the light source light so as to generate a brightness L of the illuminator light as a function of the length dimension x of the light exit window. P The distribution of the length dimension x is defined from the center (310) of the light exit window to the periphery (320) of the light exit window, wherein the brightness L P The distribution includes at least: The first interval x of length dimension x 1 , the first interval x 1 Including brightness L P The step function S(x) of the brightness L P The step function S(x) has a first gradient G 1 , G 1 =dL P / dx, The second interval x of length dimension x 2 , the second interval x 2 With the first interval x 1 are arranged adjacent to each other, wherein the second interval x 2 Including the brightness L P The function F(x), the brightness L P The function F(x) has a second gradient G 2 , G 2 =dL P / dx, and The third interval x of length dimension x 3 , the third interval x 3 With the first interval x 1 and the second interval x 2 The third interval x is arranged adjacent to one of 3 Including the brightness L P The nominal level L n (x), the brightness L P The nominal level L n (x) has a third gradient G 3 , G 3 =dL P / dx, One of the following relations is satisfied: sgn(G 1 )=-1,sgn(G 2 )=+1, and |G 1 |>G 2 >|G 3 |, as well as sgn(G 1 )=+1,sgn(G 2 )=-1, and G 1 >|G 2 |>|G 3 |, And wherein, the brightness L P The distribution in the direction from the center of the light exit window to the periphery of the light exit window includes a first brightness L 1 Via the step function S(x) to the second brightness L 2 The brightness L changes, the brightness step function S(x) includes the maximum step brightness L smax and minimum step brightness L smin At least one of which L 1 , L 2 >L smin And L 1 , L 2 <L smax .

2. The luminaire according to claim 1, in, The brightness step function S(x) includes the maximum step brightness L smax and minimum step brightness L smin , and the distribution of brightness L includes brightness L 1 , L 2 , L smin and L smax The sequence from the center of the light exit window to the periphery is L 1 -L smin -L smax -L 2 or L 1 -L smax -L smin -L 2 , where L smax >L 1 , L 2 >L smin .

3. The luminaire according to claim 1 or 2, in, The light exit window comprises a pattern (140) configured to influence or change the brightness L of the light source light into illuminator light.

4. The luminaire according to claim 3, in, The pattern is defined by the distribution of the variable light transmittance of the light exit window along the length dimension x of the light exit window.

5. The luminaire according to claim 3 or 4, in, The pattern is defined by the distribution of the variable texture of the light exit window along the length dimension x of the light exit window.

6. A luminaire according to any one of claims 3 to 5, in, The pattern is formed by the light exit window having a corresponding reflectivity R i At least two parts P i limited.

7. A luminaire according to any one of claims 3 to 6, in, The light exit window comprises at least one of a cover element and a foil (195) comprising the pattern.

8. A luminaire according to any one of the preceding claims, in, The light exit window comprises an optical element configured to influence or change the brightness L and / or L of the light source light and / or the illuminator light via beam shaping of the light. P .

9. A luminaire according to any one of the preceding claims, in, Associated with the direction DR of the length dimension x of the light exit window defined from the center (310) of the light exit window to the periphery (320) of the light exit window, the following relationship is satisfied: sgn(G 1 )=-1,sgn(G 2 )=+1, and |G 1 |>G 2 >|G 3 |, And wherein a first portion (300) of the light exit window defined around the center of the light exit window has at least one first radial dimension Ra, the at least one first radial dimension Ra comprising one of the following: The second interval x 2 and the third interval x 3 , as well as The third interval x 3 .

10. The luminaire according to claim 9, in, The at least one first radial dimension Ra is determined by the first interval x 1 Defined, wherein the first interval x 1 and at least one of the peripheries of the light exit window forms a closed loop.

11. A luminaire according to claim 9 or 10, in, The first portion has a first area A 1 , wherein the first area A 1 and the total area A of the light exit window. 1 =A 1 / A, and 0.03<R 1 <0.

14.

12. A luminaire according to any one of claims 1 to 8, in, Associated with the direction DR of the length dimension x of the light exit window defined from the center (310) of the light exit window to the periphery (320) of the light exit window, the following relationship is satisfied: sgn(G 1 )=+1,sgn(G 2 )=-1, and G 1 >|G 2 |>|G 3 |, And wherein the second portion (305) of the light exit window defined around the center (310) of the light exit window has at least one second radial dimension R b , the at least one second radial dimension R b Include one of the following: The second interval x 2 and the third interval x 3 , as well as The third interval x 3 .

13. The luminaire according to claim 12, in, The second portion has a second area A c , wherein the second area A c and the total area A of the light exit window. 2 =A c / A, and satisfies R 2 >0.

86.

14. A luminaire according to any one of the preceding claims, in, The first interval x of the length dimension x 1 Including brightness L P Variations in the range of 10%-100%.

15. A luminaire according to any one of the preceding claims, in, The first interval x 1 and the second interval x 2 The sum of S satisfies: 1cm <S<16cm。

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