Lighting lamps

Abstract

To provide a lighting fixture which performs lighting in a desired region by an optical step arranged at a lens, and is enabled in lighting at homogeneous luminosity.SOLUTION: A lighting fixture comprises a light source 31, and a lens 4 for emitting light emitted from the light source 31 as illumination light. The lens 4 comprises an optical divergence step 51 for diverging light as an optical step. In the optical divergence step 51, a plurality of unit steps 52 are arranged in a lattice shape, and in each of the unit steps 52, a light incident face 521 is constituted of a non-circular arc recessed cylinder face which is formed on the basis of a plurality of circular arcs which are different in curvature radii. The light incident face 521 of the non-circular arc recessed cylinder face is constituted so that a curvature radius of a center part in an alignment direction is smaller than curvature radii of its both-side parts.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a lighting fixture mounted on a moving body, and more particularly to a lighting fixture suitable for use as a landing light or running light of an aircraft. [Background technology]

[0002] An aircraft is equipped with landing lights and running lights as lighting fixtures. For example, as shown in the schematic configuration in FIG. 1, the left and right main wings MW of an aircraft AP are equipped with landing lights 1 at the leading edge near the fuselage, and are configured to emit light forward of the aircraft AP. As shown in FIG. 2, the landing lights 1 illuminate the front area FA of the runway when the aircraft AP lands. Although not shown in the figure, running lights may also be equipped together with the landing lights 1, and the running lights illuminate the taxiway in front of the aircraft when it is taxiing.

[0003] In recent years, lighting fixtures using semiconductor light-emitting elements as light sources have been proposed for illuminating such aircraft. For example, Patent Document 1 proposes a lighting fixture using an LED (light-emitting diode) as a light source, in which light emitted by the LED is reflected by a reflector and irradiated as illumination light with required light distribution characteristics. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-89868 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the lamp of Patent Document 1, the reflector is formed in a plate shape and curved to obtain the required light reflection characteristics, so the dimension of the lamp in the front-rear direction is large, and as a result, the thickness dimension of the lamp is large, which may be an obstacle when installing it on an aircraft. In addition, since the reflector is supported at one end, it is difficult to increase the mechanical strength, and the reflector is easily deformed by changes in the external environment in which the aircraft is placed, especially temperature changes. Even a slight deformation of the reflector can change the reflection characteristics of the LED light, and the light distribution of the illuminating light may change.

[0006] To solve these problems, a lamp using a lens with optical steps has been considered. For example, a lamp uses a lens with cylindrical surfaces arranged in a lattice pattern, that is, so-called cylindrical steps, to diverge light and illuminate a desired area. However, as will be described later, illumination using cylindrical steps has the problem that unevenness occurs in the light distribution, particularly brightness, in the illuminated area, making it difficult to achieve illumination with uniform brightness.

[0007] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a lighting fixture that is capable of illuminating a desired area with uniform brightness by using optical steps provided in a lens. [Means for solving the problem]

[0008] The present invention includes a light source and a lens that transmits light emitted from the light source and emits it as illumination light, and the lens includes a light diverging step that diverges the light. The light diverging step has a plurality of unit steps arranged in a lattice pattern, and each unit step is composed of a non-arc concave cylindrical surface composed of a curve circumscribing a plurality of arcs whose radii gradually increase while shifting the center position. The radius of curvature of the central portion of the non-arcuate cylindrical surface in the arrangement direction is smaller than the radius of curvature of both sides thereof. There are.

[0009] In the present invention, the light diverging step further includes a plurality of unit steps having different light divergence angles, and the divergence angle of the unit step in the central region in the lens arrangement direction is larger than the divergence angles of the unit steps in both side regions. Large It is preferable that the electrodes are arranged as follows.

[0010] In the present invention, the lens preferably includes light deflection steps in both side regions in a direction intersecting with the arrangement direction of the unit steps, which deflect light passing through the both side regions toward the central region. Alternatively, when the light source is composed of a plurality of light-emitting elements arranged in both the direction of arrangement of the unit steps and in a direction intersecting with the arrangement direction, it is preferable that the light-emitting surfaces of the light-emitting elements arranged in the both side regions in the direction intersecting with the arrangement direction of the unit steps are inclined toward the central region.

[0011] Furthermore, the present invention preferably has the following form. (1) A lamp includes a lamp case and an outer lens provided at an opening of the lamp case, a light source is housed within the lamp case, and the outer lens is provided with a light diverging step. (2) An inner lens is disposed between the light source and the outer lens, and the inner lens is provided with a focusing step for focusing the light emitted from the light-emitting element. (3) The light diverging step has a configuration in which a plurality of unit steps are arranged in the horizontal direction, and each unit step diverges light in the horizontal direction. Effect of the Invention

[0012] According to the present invention, the light diverging step provided on the lens can illuminate a desired area, and the desired area can be illuminated with uniform brightness. Also, according to the present invention, it is possible to provide a thin illumination with a stable light distribution. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram of a portion of an aircraft equipped with landing lights, with a partially cutaway external view. [Diagram 2] (a) is a schematic plan view showing the lighting condition, and (b) is a light distribution diagram along line BB. [Diagram 3] FIG. 2 is a schematic, partially exploded perspective view of a landing light; [Figure 4] Horizontal cross section of the landing light. [Diagram 5] Schematic diagram of an enlarged portion of Figure 4. [Figure 6] FIG. 6 is a schematic diagram similar to FIG. 5 of a landing light of a reference example. [Figure 7] 11A to 11C are schematic diagrams illustrating a design example of a non-arcuate concave cylindrical surface of a unit step. [Figure 8] FIG. 6 is a horizontal cross-sectional view of a main part of the landing light of the second embodiment. [Figure 9] 11A and 11B are diagrams of a landing light of embodiment 3, in which (a) is a front view of the outer lens, and (b) is a vertical cross-sectional view of a main part of the landing light. [Figure 10] FIG. 11 is a vertical cross-sectional view of a main part of the landing light of the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Next, an embodiment of the present invention will be described with reference to the drawings. As shown in Fig. 1, a cutaway external view of a portion of an aircraft AP equipped with a landing light 1 is formed in a recess that opens forward at the leading edge of the main wing MW of the aircraft AP, and a lamp housing chamber 100 is provided therein. The landing light 1 is housed in the lamp housing chamber 100 and configured to emit illumination light through the opening. A translucent front cover 101 is attached to an opening edge 102 of the opening, and the front cover 101 seals the interior of the lamp housing chamber 100 to protect the landing light 1 from the external environment.

[0015] Fig. 3 is an exploded perspective view of the landing light, and Fig. 4 is a horizontal cross-sectional view of the landing light 1. This landing light is equipped with a circular dish-shaped lamp case 2 with an opening at the front, in which a light source substrate 3 and an inner lens 4 are housed, and an outer lens 5 is attached to a flange portion 21 at the front opening of the lamp case 1. As shown in Fig. 1, this landing light 1 is fixed and supported in the lamp housing chamber 100 with the outer lens 5 facing forward, i.e., with the outer lens 5 facing the front cover 101, and when lit, illumination light is emitted through the outer lens 5 and further through the front cover 101 to be irradiated toward the front of the aircraft AP.

[0016] The light source substrate 3 is formed in a circular plate shape, and is supported along the inner bottom 20 of the lamp case 2 by a screw (small screw) 22. A plurality of light emitting elements as a light source, LEDs (light emitting diodes) 31 emitting white light in this case, are mounted on the front surface of the light source substrate 3 (hereinafter, the side facing the outer lens 5 is referred to as the front). In addition, although not shown, the light source substrate 3 is formed with required wiring for supplying power to the LEDs 31. The plurality of LEDs 31 are mounted in a required arrangement over almost the entire area of ​​the light source substrate 3 with their respective light emitting surfaces facing forward. That is, the LEDs 31 are mounted in a plurality of arrangements in both the horizontal and vertical directions. In order to simplify the explanation, a smaller number of LEDs 31 than the actual number is shown in FIG. 3 and FIG. 4.

[0017] The inner lens 4 is supported by the light source substrate 3 with a required distance from the front surface of the light source substrate 3 by screws 23. The inner lens 4 is made of a light-transmitting material, such as a transparent resin, and optical steps 41 are integrally formed on the rear surface of the inner lens 4 at positions facing the LEDs 31. That is, the optical steps 41 are formed at positions where the light emitted from the light-emitting surface of each LED 31 is incident.

[0018] 3 and 4 each show an enlarged view of one optical step 41, and this optical step 41 is configured as a light-collecting step 41 that collects light emitted from the light-emitting surface of the LED 31 and functions as a condenser lens. This light-collecting step 41 protrudes backward from the rear surface of the inner lens 4, and the outer peripheral surface 410 is formed in a shape similar to a truncated cone with a spindle surface that bulges outward to some extent. The upper bottom surface of this light-collecting step 41 faces the light-emitting surface of the LED 31 as a light-entering surface. An inverted cone-shaped recess is formed on this upper bottom surface, and the inner bottom surface of this recess is configured as a first entrance surface 411, and the inner peripheral surface 412 of the recess is configured as a second entrance surface. The first entrance surface 411 is formed as a spherical surface, and the second entrance surface 412 is formed as an inverted cone surface.

[0019] The outer lens 5 is made of a colorless light-transmitting plate that allows light to pass through, and is fixed and supported in a state of being fitted inside the flange portion 21 provided on the periphery of the lamp case 2. The outer lens 5 is also made of a light-transmitting material, for example, a transparent resin. The outer lens 5 is formed in a roughly flat plate shape, and its front surface is formed flat as a light emission surface, but its rear surface is formed with an optical step for obtaining a predetermined light distribution, that is, a light diverging step 51 for diverging light. The outer lens 5 may be curved in a convex shape toward the front.

[0020] Before explaining the light dispersion step 51, the illumination distribution, particularly the brightness distribution (illuminance distribution) when illuminating with the landing light 1 will be explained. As shown in Fig. 2(a), the illumination light of the landing light 1 is irradiated in an oblique direction to the runway surface. Therefore, when the required area to be irradiated is, for example, an area close to a circle, the luminous flux shape of the light emitted from the landing light 1 (here, "luminous flux" means light having a required cross-sectional area), i.e., the cross-sectional shape of line BB in the figure, is set to an illumination distribution P0 that is elliptical or oval that is flattened in the horizontal direction, as shown in Fig. 2(b).

[0021] Therefore, in this embodiment 1, the light distribution is obtained by the light divergence step 51 of the outer lens 5. FIG. 5 is a schematic diagram enlarging a part of FIG. 4, and the light emitted from the light emitting surface of the LED 31 is transmitted through the inner lens 4, and at that time, the light is emitted from the front surface of the inner lens 4 as a substantially parallel light beam by the light collecting step 41. That is, in the light collecting step 41, among the light emitted from the light emitting surface of the LED 31, the light emitted from the central region of the light emitting surface is incident on the first incident surface 411, refracted here, and emitted from the front surface of the inner lens 4. In addition, the light emitted from the peripheral region of the light emitting surface of the LED 31 is incident on the second incident surface 412, refracted here, and then internally reflected at the outer peripheral surface 410 to be emitted from the front surface of the inner lens 4.

[0022] As a result, the light emitted with a required spread from the light-emitting surface of the LED 31 is converged by passing through the light-collecting step 41, and is emitted as a nearly parallel or slightly spread light beam from the front surface of the inner lens 4. This light is then incident on the rear surface of the outer lens 5, and as it passes through the outer lens 5, it is diverged horizontally by the light divergence step 51 of the outer lens 5 and is emitted.

[0023] In order to diffuse the light emitted from the outer lens 5 in the horizontal direction, the light diffusion steps 51 are formed as lattice-like steps in which vertically extending strip-like unit steps 52 are arranged in multiple rows in the horizontal direction. In order to diffuse the light in the horizontal direction, each unit step 52 has a horizontal cross section formed into a concave curved surface.

[0024] As shown in the schematic diagram of Fig. 6, the light diverging step 51A, which is the unit step 52, has an entrance surface 520 of a unit step 52A into which light is incident, which is configured as a concave cylindrical surface having a horizontal cross section shaped like an arc (hereinafter referred to as an arcuate concave cylindrical surface). The light incident on this unit step 52A is refracted at the entrance surface 520 and diverged in the horizontal direction. At this time, since the entrance surface 520 of the unit step 52A is an arcuate concave cylindrical surface, the spread of divergence of light incident on the center part (the horizontal center part, the same below) of the entrance surface 520 is smaller than the spread of divergence of light incident on both sides away from the center part (the both sides sandwiching the center part in the horizontal direction, the same below).

[0025] Therefore, the light distribution of the landing light by the light diverging step 51A in which the unit steps 52A, each of which has an entrance surface 520 having an arc-shaped concave cylindrical surface, are arranged in a lattice pattern will be an illumination light distribution P1, as shown in Figure 6, in which the illuminance is high in the central area and decreases toward both side areas, making it difficult to illuminate the road surface with uniform brightness.

[0026] On the other hand, the unit step 52 constituting the light diverging step 51 of the embodiment 1 shown in Fig. 5 has a horizontal cross-sectional shape of its incident surface 521 formed as a non-arc cylindrical surface, that is, a concave cylindrical surface in which the radius of curvature gradually increases from the horizontal center toward both sides (hereinafter referred to as a non-arc concave cylindrical surface). For example, as shown in Fig. 7, a plurality of circles with gradually increasing radii while shifting the center positions are drawn, here an arc C1 of radius r1, an arc C2 of radius r2, and an arc C3 of radius r3, and the concave cylindrical surface is formed by curves circumscribing these arcs.

[0027] In the outer lens 5 having the light diverging steps 51 in which the unit steps 52 are arranged in a lattice pattern, as shown in Fig. 5, when the light emitted by the LED 31 passes through the inner lens 4 and is incident on the incident surface 521 of the unit step 52, the incident light is diverged by refraction at the incident surface 521 and is emitted from the front surface of the outer lens 5. At this time, since the incident surface 521 of the unit step 52 is a non-arcuate concave cylindrical surface and the radius of curvature of the center is smaller than that of both sides, the light incident on this center is refracted at a larger angle than that of both sides and is diverged at a larger angle in the horizontal direction. In other words, the light diverged at the center of the incident surface 521 is irradiated in a state where it is spread horizontally and left and right to the target illumination area.

[0028] On the other hand, since the radius of curvature of both sides of the entrance surface 521 of the unit step 52 is larger than that of the center, the light incident on these sides is refracted at a smaller angle than that of the center, and the horizontal divergence angle is small. This divergence angle is designed to correspond to the illumination area, so that the light is irradiated in a state that spreads horizontally in the left and right directions to the desired illumination area. This prevents the brightness of the central area of ​​the desired illumination area from being partially high, and an illumination light distribution P with approximately uniform brightness in the horizontal direction is obtained.

[0029] Such control of the illumination light distribution is performed in each of the multiple unit steps 52 that make up the light divergence step 51, so that the illumination light distributions of these multiple unit steps 52A are synthesized, and the illumination area illuminated by the landing light 1 becomes an illumination light distribution P with approximately uniform brightness in the horizontal direction, preventing the brightness of the central area from being partially high.

[0030] In this embodiment 1, the desired lighting distribution is obtained by the light diverging steps 51 formed on the plate-shaped outer lens 5, so the thickness dimension of the lamp in the front-to-rear direction is smaller than that of a configuration equipped with a curved reflector as in Patent Document 1, resulting in a thin landing light with a small dimension in the front-to-rear direction. In addition, since the outer lens 5 is supported by the lamp case 2 at its periphery, it is not deformed by changes in the external environment such as temperature changes, compared to a configuration using a cantilevered reflector as in Patent Document 1, and a stable lighting distribution is obtained.

[0031] In the first embodiment, as shown in Fig. 7, the entrance surface 521 of the unit step 52, i.e., the non-arc concave cylindrical surface, is designed based on the arcs C1 to C3 with three different radii of curvature, but the radii of curvature r1 to r3 of the arcs C1 to C3 may be designed to be different values, or the relative positions of the arcs C1 to C3 may be appropriately changed. The number of arcs may also be changed. By designing the non-arc shape in this way, the divergence state of light on the entrance surface 521 of the unit step 52A can be adjusted to obtain a desired light distribution.

[0032] (Embodiment 2) 8 is a horizontal cross-sectional view of the main part of the landing light of the second embodiment, and the same reference numerals are used for parts equivalent to those of the first embodiment. The second embodiment is the same as the first embodiment in that the light diverging step 51 of the outer lens 5 is composed of a plurality of unit steps each having a non-arcuate concave cylindrical surface, but in the second embodiment, the light diverging step 51 is composed of unit steps 52a, 52b, and 52c having different shapes of the entrance surface, and these unit steps 52a, 52b, and 52c are composed of non-arcuate concave cylindrical surfaces having different divergence angles of light diverged from each entrance surface.

[0033] In the second embodiment, the unit steps 52a, 52b, and 52c are configured with three types of entrance surfaces 521a, 521b, and 521c having relatively small, medium, and large divergence angles. big The unit steps 52a of the incident surface 521a are arranged, and the divergence angle is larger in the intermediate regions on both sides than in the central region. small The unit steps 52b of the incident surface 521b are arranged, and the divergence angle is further increased in the both outer side regions. small The unit steps 52c of the incident surface 521c are arranged.

[0034] Here, when designing the incident surfaces 521a to 521c with different divergence angles, a non-arcuate concave cylindrical surface with different light divergence angles can be obtained by appropriately adjusting the radii, number, and relative positions of multiple circles as shown in Fig. 7. Note that Fig. 8 shows an example in which two unit steps 52a and 52b each having incident surfaces with the same divergence angle are arranged, but the number is not limited thereto.

[0035] In the outer lens 5 of embodiment 2, which has a light divergence step 51 in which unit steps 52a, 52b, and 52c of the incident surface with different divergence angles are arranged horizontally, the divergence angle of the unit step 52a in the central region is made larger than that of each unit step 52b, 52c in the intermediate region and both side regions, so that the divergence angle of light incident on and transmitted through the central region of the outer lens 5 is larger when emitted than the light incident from the intermediate region of the outer lens 5 to both side regions.

[0036] As a result, in the second embodiment, the light diverged from the unit steps 52a in the central region of the outer lens 5 is irradiated in a state that spreads horizontally to the left and right with respect to the target illumination region, preventing the brightness of the central region from being partially high. The same applies to the divergence of light from the unit steps 52b in the intermediate region, preventing the brightness of the intermediate region from being partially high. This provides an illumination light distribution with approximately uniform brightness in the horizontal direction.

[0037] In the second embodiment, all of the unit steps 52a, 52b, and 52c are formed of non-arcuate concave cylindrical surfaces, but they may be formed to include unit steps of arcuate concave cylindrical surfaces with different radii of curvature. In this case, too, the unit steps of the arcuate concave cylindrical surfaces with smaller radii of curvature are arranged in the central region, and the unit steps of the arcuate concave cylindrical surfaces with relatively larger radii of curvature are arranged in the regions on both sides.

[0038] According to the second embodiment, the thickness dimension of the lamp in the front-rear direction is smaller than that of a lamp using a reflector, and a thin landing light is obtained. Also, a stable lighting distribution that is resistant to changes in the external environment such as temperature changes is obtained. Moreover, by appropriately designing the number of each of the multiple unit steps 52 with different divergence angles that make up the light divergence step 51, the divergence state of light from the outer lens 5 as a whole can be adjusted to obtain a desired lighting distribution.

[0039] (Embodiment 3) As shown in FIG. 1, the landing light 1 is installed in a lamp housing 100 provided in the main wing MW, and is configured to irradiate illumination light through the opening. Therefore, a part of the light emitted from the outer lens 5 of the landing light 1 may be blocked by the opening edge 102. In the landing light 1 of the first and second embodiments, the light divergence step 51 provided in the outer lens 5 suppresses the light divergence in both horizontal directions, so the light is rarely blocked by the opening edge 102. However, the light divergence is not particularly controlled in the vertical direction of the outer lens 5, so that a part of the light emitted from the outer lens 5 may be blocked by the opening edge 102 in both vertical regions of the outer lens 5, i.e., the upper region and the lower region. Such blocked light does not contribute to illumination, and the utilization efficiency of the light emitted by the LED is reduced.

[0040] Fig. 9(a) is a schematic front view of the outer lens of the landing light 1 of the third embodiment. In the third embodiment, the upper and lower regions of the outer lens 5 are formed with light deflection steps 53, 54 that deflect light toward the central region. When viewed from the front of the outer lens 5, these light deflection steps 53, 54 are regions that divide the upper and lower regions of the circular outer lens 5 by horizontal dividing lines. Fig. 9(b) is a vertical cross-sectional view of the main part, in which the upper region of the outer lens 5 is formed as a lower light deflection step 53 in which the lens thickness gradually increases downward, and the lower region is formed as an upper light deflection step 54 in which the lens thickness gradually increases upward.

[0041] By providing these light deflection steps 53, 54, light incident on the upper region of the outer lens 5 is refracted in the lower light deflection step 53 so that its emission direction is directed downward. Also, light incident on the lower region of the outer lens 5 is refracted in the upper light deflection step 54 so that its emission direction is directed upward. This makes it difficult for light emitted from the upper and lower regions of the outer lens to be blocked by the opening edge 102, and even if light is blocked, the amount of light blocked is small. Therefore, the efficiency of LED light utilization can be improved.

[0042] Although not shown in the drawings, the light deflection steps 53, 54 may be formed in the upper and lower regions of the rear surface of the outer lens 5. Even in this case, the light deflection steps are formed as lower light deflection steps in which the lens thickness gradually increases downward in the upper region, and as upper light deflection steps in which the lens thickness gradually increases upward in the lower region.

[0043] (Embodiment 4) 10 is a schematic vertical cross-sectional view of the landing light 1 of embodiment 4. The embodiment 4 can be considered a modification of the embodiment 3, and like the embodiment 3, is intended to prevent a portion of the light emitted from the outer lens 5 of the landing light 1 from being blocked by the opening edge 102 when the landing light is installed in the lamp housing chamber 100.

[0044] In this embodiment 4, the front surfaces of the upper region 32 and the lower region 33 of the light source substrate 3, i.e., the mounting surfaces on which the LEDs 31 are mounted, are inclined toward the central region. In the upper region 32, the mounting surface is inclined downward at a required angle, and in the lower region 33, the mounting surface is inclined upward at a required angle. Therefore, the light emitting surface of the LEDs 31 mounted in the upper region 32 of the light source substrate 3 is inclined downward by the required angle. Also, the light emitting surface of the LEDs 31 mounted in the lower region 33 of the light source substrate 3 is inclined upward by the required angle.

[0045] As a result, light incident on the inner lens 4 from the LEDs 31 in the substrate upper region 32 is directed downward, and light emitted from the inner lens 4 is deflected downward. Also, light incident on the inner lens 4 from the LEDs 31 in the substrate lower region 33 is directed upward, and light emitted from the inner lens 4 is deflected upward. As a result, light emitted from the inner lens 4 and then from the outer lens 5 is less likely to be blocked by the opening edge 102, and even if light is blocked, the amount of light blocked is small. Therefore, the effect of shading on the efficiency of LED light utilization can be negligible, and utilization efficiency can be increased.

[0046] In this embodiment 4, the light-emitting surfaces of the LEDs 31 in the substrate upper region 32 and substrate lower region 33 are inclined, and accordingly, the lens upper region 42 and lens lower region 43 of the inner lens 4 arranged to face these LEDs 31 are similarly inclined. Therefore, the light-collecting steps 41 in the lens upper region 42 and lens lower region 43 are also inclined so as to face the light-emitting surfaces of the LEDs 31.

[0047] The present invention is not limited to the configuration of the embodiment described above, and light emitting elements other than LEDs can be used as the light source. In addition, the number of LEDs, i.e., the number of light emitting elements as the light source, and the number of light collecting steps of the inner lens arranged opposite the light source are not limited. Furthermore, the shape of the light collecting step is not limited to the shape described in the embodiment, and may be a step with light collecting properties, for example, a convex spherical step.

[0048] In the embodiment, the outer lens is formed with light diverging steps and light deflecting steps, but a second inner lens separate from the inner lens may be provided and these steps may be provided on the second inner lens. That is, the second inner lens may be provided in front of the inner lens shown in the embodiment, and the second inner lens may be configured to diverge light horizontally or deflect light toward the center. In this case, the outer lens is simply configured as a light-transmitting cover that transmits light.

[0049] Furthermore, the outer lens in the present invention does not necessarily have to be positioned at the outermost part of the lamp. For example, a translucent cover or a clear lens may be arranged on the outside of the outer lens to protect the outer lens or to enhance the design effect.

[0050] In the embodiment, the light collecting step is disposed on the inner lens, but the light collecting step and the light source may be configured as a light source module integrally configured, and in the case of providing such a light source module, the inner lens may be omitted. Alternatively, the outer lens may be configured as a plain lens, and the light diffusing step or the light deflecting step may be formed on the inner lens.

[0051] The illumination lamp of the present invention is not limited to the landing light of the aircraft shown in the embodiment, but can be applied as a running light of the aircraft or a lamp for other aircraft. It can also be applied as a lamp for lighting a moving body such as an automobile or a train. In addition, according to the light distribution required for the lamp, the light diverging step provided on the lens can be configured as a lamp that diverges light in the vertical direction. [Explanation of symbols]

[0052] 1 Landing light (lighting fixture) 2 Lighting case 3 Light source board 4 Inner lens 5 Outer Lens 31 LED (light emitting element: light source) 32 Lower board area 33 Upper area of ​​board 41 Optical step (light collection step) 42 Upper Lens Area 43 Lower Lens Area 51 Light divergence step 52, 52a, 52b, 52c Unit Step 521, 521a, 521b, 521c Incident surface (non-arc concave cylindrical surface) 53 Lower Light Deflection Step 54 Upper Light Deflection Step 100 Lamp Storage Room 101 Front cover 102 Opening edge

Claims

1. An illumination fixture comprising a light source and a lens that transmits light emitted from the light source and emits it as illumination light, the lens having a light divergence step that diverges light, the light divergence step being a plurality of unit steps arranged in a lattice pattern, each unit step being composed of a non-arc concave cylindrical surface composed of a curve circumscribing a plurality of arcs whose radii gradually increase as their center positions shift, the non-arc concave cylindrical surface having a smaller radius of curvature at a central portion in the arrangement direction than at both side portions, the plurality of unit steps being composed of a plurality of unit steps having different light divergence angles, and arranged so that the divergence angle of the unit step in the central region in the arrangement direction of the lens is greater than the divergence angle of the unit step in both side regions.

2. 2. The illumination lamp according to claim 1, wherein the lens includes light deflection steps in both side regions in a direction intersecting with an arrangement direction of the unit steps, the light deflection steps deflecting light passing through the both side regions toward a central region.

3. 3. The illumination lamp according to claim 1, wherein the light source is composed of a plurality of light-emitting elements arranged in a direction in which the unit steps are arranged and in a direction intersecting the direction in which the unit steps are arranged.

4. 4. The illumination lamp according to claim 3, wherein the light emitting elements disposed in the two side regions in a direction intersecting the direction in which the unit steps are arranged have light emitting surfaces inclined toward the central region.

5. 5. The illumination lamp according to claim 4, comprising a lamp case and an outer lens provided at an opening of the lamp case, the light source being housed within the lamp case, and the light divergence step being provided on the outer lens.

6. 6. The illumination lamp according to claim 5, wherein an inner lens is disposed between the light source and the outer lens, and the inner lens is provided with a focusing step for focusing the light emitted from the light-emitting element.

7. 7. The illumination lamp according to claim 1, wherein the light diverging step is configured by arranging a plurality of unit steps in a horizontal direction, and each unit step diverges light in the horizontal direction.

8. 8. The illumination lamp according to claim 7, which is mounted in a lamp housing chamber provided in the fuselage of an aircraft and emits light through an opening of the lamp housing chamber.

9. 9. The lighting fixture according to claim 8, configured as a landing light or a running light of an aircraft.

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