Portable lighting devices

Abstract

The present invention provides a portable lighting device, which makes the illumination range into a specific shape, makes the illumination within the illumination range roughly uniform, and does not require focus adjustment from short distance to long distance. The portable lighting device (1) of the present invention comprises: a light source (2); a collimator (3) for incident light from the light source (2); and a fly-eye lens (4) for incident light through the collimator 3, and comprises a plurality of lens units (40a) arranged two-dimensionally on the incident side of the light, and a plurality of lens units (40b) arranged two-dimensionally on the exit side in a manner opposite to each of the lens units (40a) on the incident side, each lens unit (40) being rectangular or hexagonal, and the illumination shape is rectangular or hexagonal.

Description

Technical Field

[0001] The present invention relates to a portable lighting device. Background Art

[0002] Conventionally, a portable lighting device has been proposed that uses a mask of a specific shape to make the irradiation range of light into a specific shape, and uses a lens array to make the illuminance of light in the irradiation range substantially uniform (see Patent Document 1).

[0003] <Prior Art Literature>

[0004] <Patent Documents>

[0005] Patent Document 1: Japanese Patent No. 4625837 Summary of the invention

[0006] <Problems to be Solved by the Invention>

[0007] However, in order to make the irradiation range into a specific shape, the portable lighting device of the prior art arranges a mask in the optical path and uses an imaging lens for imaging the image of the mask. Therefore, when irradiating light of a specific shape from an irradiation position at a different distance from the portable lighting device, it is necessary to move the position of the imaging lens.

[0008] The object of the present invention is to provide a portable lighting device, which makes the irradiation range into a specific shape, makes the illumination within the irradiation range roughly uniform, and does not require focus adjustment from short distance to long distance.

[0009] <Methods used to solve the problem>

[0010] In order to solve the above problems, the present invention provides a portable lighting device, comprising: a light source; a collimator for incident light from the light source; and a fly-eye lens for incident light through the collimator, and comprising a plurality of lens units arranged in two dimensions on the incident side of the light, and a plurality of lens units on the exit side arranged in two dimensions in a manner opposite to each of the lens units on the incident side, each lens unit being rectangular or hexagonal, and the irradiation shape being rectangular or hexagonal.

[0011] Preferably, the size of one side of each of the lens units on the incident side and the exit side is 500 μm or less, and the distance between the lens effective portion of one lens unit and the lens effective portion of another lens unit between adjacent lens units is 10 μm or less.

[0012] It is preferable that a gap between lens cells arranged in one row and lens cells arranged in a row adjacent to the one row has a positional deviation of 3 μm or less in a direction perpendicular to the row arrangement direction.

[0013] Preferably, among the positions illuminated by light emitted from the portable lighting device, when a range where the illuminance is 75% or more of the maximum value is set as the main irradiation range, the width of the main irradiation range from 5% of the maximum value to within 20% of the width of the main irradiation range.

[0014] Preferably, the main irradiation range is a rectangle, and the divergence angle of one side of the rectangle is 30° to 45°, and the divergence angle of the other side is 20° to 30°.

[0015] It is preferable that no optical component for exerting an optical effect on the light formed by the fly-eye lens is included on the light emitting side of the fly-eye lens.

[0016] Preferably, the light exiting side of the fly-eye lens does not include an optical component for shaping or homogenizing light. In the case where the optical component for shaping or homogenizing light is not included, a more compact portable lighting device can be provided.

[0017] Preferably, the light source, the collimator, and the fly-eye lens are held in a housing, and a dust cover is disposed on the light emitting side of the fly-eye lens in the housing.

[0018] A lens having a variable distance from the light source may be included on the light emitting side of the compound eye lens, and a zoom function may be provided to expand the divergence angle by changing the distance between the lens and the light source. By having a zoom function, the irradiation range can be varied, thereby providing a portable lighting device that further meets the application.

[0019] It is preferred that the illumination changes along with the operation of the above-mentioned zoom function.

[0020] It is preferable that the light source is a light source that generates visible light, infrared light or ultraviolet light.

[0021] <Effects of the Invention>

[0022] According to the present invention, a portable lighting device can be provided, which makes the irradiation range into a specific shape, makes the illumination within the irradiation range roughly uniform, and does not require focus adjustment from a short distance to a long distance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 1 is a schematic diagram showing a basic optical system of the portable lighting device 1 according to the first embodiment.

[0024] Figure 2 1 and 2 are diagrams for explaining a fly-eye lens 4, wherein (a) is a front view, (b) is a side view, and (c) is an enlarged view of a portion A of (b).

[0025] Figure 3These are enlarged photographs of the fly-eye lens 4, (a) is an embodiment, and (b) is a comparative embodiment.

[0026] Figure 4 This is a table showing the axial thickness, the curvature radius of the lens unit 40, and the rise angle when the fly-eye lens 4 is designed using various materials having different refractive indices.

[0027] Figure 5 yes Figure 2 The enlarged view of part B of (c), in which the solid line is the implementation method and the dotted line is the comparison method.

[0028] Figure 6 This is a graph showing the measured straightness of the gaps between the adjacent lens units 40 .

[0029] Figure 7 The photographs are of illumination patterns of light irradiated onto a screen when the screen is arranged at a distance of 2 m from the portable lighting device 1 , wherein (a) is a case where the portable lighting device 1 of the embodiment is used, and (b) is a case where a portable lighting device of a comparative method is used.

[0030] Figure 8 : is a table showing the curvature radius R, lens size, and axial thickness of the lens unit of the portable lighting device 1 of different sizes.

[0031] Fig. 9 1 is a diagram showing simulation results of an irradiation pattern of light irradiated onto a screen 4 m forward from the portable lighting device 1 according to the embodiment.

[0032] Fig.10 It is shown Fig. 9 Graph of the illumination in the X direction.

[0033] Fig.11 1 is a diagram showing a deformation mode of the lens unit 40 .

[0034] Fig.12 1 is a schematic diagram showing a basic optical system of a portable lighting device 201 according to the second embodiment.

[0035] Fig.13 (a) shows the simulation results of the irradiation pattern in the first embodiment, and (b) to (d) show the simulation results of the irradiation pattern on the screen when the distance L between the outer surface of the fly-eye lens 4 and the inner surface of the zoom lens 210 is changed in the range of 5 to 50 mm.

[0036] Description of Reference Numerals

[0037] 1 Portable lighting device

[0038] 2 Light Source

[0039] 3 Collimator

[0040] 4 Compound Eye Lens

[0041] 40 lens units

[0042] 40a Incident side lens unit

[0043] 40b: output side lens unit DETAILED DESCRIPTION

[0044] (First Embodiment)

[0045] Hereinafter, a portable lighting device 1 according to a first embodiment of the present invention will be described. Figure 1 1 is a schematic diagram showing a basic optical system of the portable lighting device 1 according to the first embodiment.

[0046] The portable lighting device 1 is a so-called flashlight, and includes a light source 2, a collimator 3, a fly-eye lens 4, and a cover plate 5 in order in the optical axis direction, and these are held in a housing 10. In addition, a battery receiving portion 6 for supplying power to the light source 2 is provided in the housing 10.

[0047] (Light Source 2)

[0048] The light source 2 is, for example, a light source that generates visible light, infrared light, ultraviolet light, or the like, a solid light source such as a light emitting diode, or a lamp.

[0049] (Collimator 3)

[0050] The collimator 3 is a lens or a reflector, which makes the light emitted from the light source 2 substantially parallel. In the embodiment, the collimator 3 is a reflector and lens, has a cup-shaped mirror surface, and uses reflection and focusing to make the light emitted from the light source 2 substantially parallel in a constant range.

[0051] (Cover 5)

[0052] The cover plate 5 is made of transparent resin and is provided at the opening on the light-emitting side of the housing 10. The cover plate 5 prevents dust and water from entering the housing, thereby ensuring the durability and environmental resistance of the portable lighting device 1.

[0053] (Fly-eye lens 4)

[0054] Figure 2 is a diagram for explaining the fly-eye lens 4, Figure 2 (a) is the main view, Figure 2 (b) is the side view, Figure 2 (c) is Figure 2 (b) is an enlarged view of part A. Figure 3 (a) shows an enlarged photograph of the fly-eye lens 4 of the embodiment. Figure 3(b) shows an enlarged photograph of a fly-eye lens 4' of a comparative embodiment.

[0055] (Configuration of Fly-Eye Lens 4)

[0056] like Figure 2 As shown in (c), the fly-eye lens 4 includes a plurality of lens units 40a arranged two-dimensionally on the incident side of the light from the collimator 3, and a plurality of lens units 40b arranged two-dimensionally on the exit side in a manner opposite to each lens unit 40 on the incident side. The lens unit 40a and the lens unit 40b are respectively arranged on both sides of a plate-like component, and they have the same shape. When there is no need to distinguish them for description, they are described as the lens unit 40.

[0057] The fly-eye lens 4 divides the light beam by the lens unit 40a on the incident side, and guides each light beam to the irradiation area by the lens unit 40b on the emission side. The shape of the light beam in the irradiation area becomes a rectangular shape corresponding to the shape of the lens unit 40.

[0058] By using the fly-eye lens 4, the brightness of the light source can be dispersed unevenly, so that the same illumination distribution can be obtained on the irradiated surface.

[0059] (Material of fly-eye lens 4)

[0060] Figure 4 This is a table showing the on-axis thickness (μm), the radius of curvature R of the lens unit 40, and the rising angle (θ°) (original Japanese: rising angle) at the edge of the protruding lens unit 40 when the fly-eye lens 4 is designed using various materials with different refractive indices.

[0061] like Figure 4 As shown in FIG. 1 , if the refractive index is different, the shape of the lens unit 40 changes, and the lower the refractive index, the larger the rise angle θ. In the embodiment, considering the ease of mold making in glass molding, mold release during molding, and mold durability, a low-melting-point glass, VC82, having a small rise angle θ is used as the material of the lens unit 40 (fly-eye lens 4).

[0062] (Dimensions of fly-eye lens 4)

[0063] like Figure 3 As shown in (a) of the embodiment, the fly-eye lens 4 of the embodiment is composed of a plurality of rectangular lens units 40 with an aspect ratio of 6:4, for example, arranged in a two-dimensional manner vertically and horizontally. In addition, the fly-eye lens 4 of the embodiment is a so-called micro fly-eye lens of a relatively small size. Figure 2 As shown in (a), the overall shape is a substantially rectangular shape, and the size of one side is 10 mm to 30 mm, and is 20 mm in the embodiment.

[0064] (Dimensions of the lens unit 40)

[0065] The size (pitch) of each lens unit 40 in the fly-eye lens 4 is preferably 500 μm or less, more preferably 400 μm or less, and in the embodiment, 330 μm×220 μm. If the lens unit 40 is set to an aspect ratio of 6:4 with a horizontal length of 330 μm and a vertical length of 220 μm, 7,300 lens units are arranged in a Φ26 light beam. It should be noted that the size of one side of the lens unit 40 is 1 / 50 to 1 / 100 of the size of one side of the fly-eye lens 4 in the embodiment.

[0066] (Axis thickness of fly-eye lens 4)

[0067] like Figure 2 As shown in (c), the distance (axial thickness) between the vertex of the convex portion of the lens unit 40a on the incident side and the vertex of the convex portion of the lens unit 40b on the exit side opposite to the lens unit 40a on the incident side is preferably 1000 μm or less.

[0068] In the embodiment, VC82 is used as the material, such as Figure 4 As shown, the axial thickness is 800 μm and the radius of curvature R of the lens is 344 μm.

[0069] (Dimensions of the fly-eye lens 4 of the comparative method)

[0070] Hereinafter, a conventional general fly-eye lens will be described as a comparative method.

[0071] like Figure 3 As shown in (b), the comparative fly-eye lens 4' is the same as the embodiment, and is composed of a plurality of rectangular lens units 40' with an aspect ratio of 6:4, for example, arranged in a two-dimensional manner vertically and horizontally.

[0072] However, the size of the lens unit 40 ′ of each fly-eye lens 4 ′ of the comparative embodiment is larger than that of the embodiment, for example, 1200 μm×800 μm, and at least one side is 700 μm or more.

[0073] The distance (axial thickness) between the apex of the convex portion of the incident-side lens cell of the comparative embodiment and the apex of the convex portion of the exit-side lens cell opposite to the incident-side lens cell is about 5 mm (5,000 μm).

[0074] Such a comparative lens unit 40' is conventionally manufactured for use as a light source for a projector, and when used, a diffuser plate or a light guide is used in the optical system to improve the uniformity of light, or the edges of the rectangular periphery are formed by imaging the ridges of the aperture. Therefore, even if the size of the lens unit 40' is not particularly small, it is sufficient in terms of function.

[0075] (Configure many)

[0076] However, in a small lighting device such as the portable lighting device 1, the size of the fly-eye lens 4 is small, for example, a 20 mm square. The number of fly-eye lenses that can be arranged in the 20 mm square is as small as 448 in the comparative method. In contrast, 6600 units can be arranged in the embodiment.

[0077] The number of lens units 40 also affects the uniformity of illumination of the irradiated light, and the more lens units 40 there are, the more favorable it is for uniform illumination. According to the embodiment, even if the size of the fly-eye lens 4 is the same, 10 times more lens units 40 can be configured compared to the comparative method. In addition, the size of the lens unit 40 is also small. Therefore, it is possible to achieve lightweight and miniaturization, and to achieve uniform illumination of the irradiated light and sharp edges.

[0078] (width d less than 10μm)

[0079] Figure 5 yes Figure 2 The enlarged view of the B portion of (c) shows that the solid line is the embodiment and the dotted line is the comparison method. In the embodiment, between the adjacent lens units 40 in each plane on the incident side or the exit side, the width d between the lens effective portion of one lens unit 40 and the lens effective portion of another lens unit 40, that is, the width d of the lens ineffective portion is less than 10 μm.

[0080] The lens effective portion refers to a portion of the lens unit 40 that contributes to light focusing, and the lens ineffective portion refers to a portion of the periphery of the lens effective portion that does not contribute to light focusing in the lens unit 40 and diverges and scatters light.

[0081] For example, in the comparison method, Figure 5 In the cross section through the vertices of each lens unit 40′ shown in the figure, the width d′ is the width d′ (distance) between the inflection point P of the line formed by the contour of one lens unit 40′ and the inflection point P of the line formed by the contour of the adjacent lens unit 40′, but in the embodiment, the existence of the inflection point P is to an extent that it cannot be confirmed, and the width of the light scattering portion is less than 10 μm.

[0082] (Effect of width d less than 10 μm: straightness)

[0083] Figure 6 Yes Figure 3 The graph shown is a graph for measuring the positional deviation (straightness) in the Y direction of the gap extending in the X direction between the lens units 40 adjacent to each other in the Y direction, for example, when the direction in which the lens units 40 are arranged is set to the XY direction.

[0084] Figure 6 The black dots in the figure are Figure 3 The gap D between the lens units 40 of the fly-eye lens 4 in the embodiment shown in (a), that is, the straightness of the line C, the cross is Figure 3 The gap between the lens units 40' of the fly-eye lens 4' of the comparative method shown in (b), that is, the straightness of the line C'. Figure 6 The position of the gap at the left end of is set as zero of the Y coordinate, and the position of the gap D in the Y direction when the X direction is directed to the right side of about 1200 μm in the figure is plotted.

[0085] As shown in the graph, in the comparative method, the position of the gap D' is in the range of about -1.0 μm to +5.5 μm. That is, the amplitude m' of the position in the Y direction is about 6.5 μm.

[0086] In contrast, in the embodiment, the position of the gap D is in the range of about -1.0 to +0.5 μm. That is, the amplitude m of the position in the Y direction is 1.5 μm. It should be noted that in the embodiment, it is not limited to 1.5 μm, and can be 3 μm or less, and more preferably 2 μm or less.

[0087] Figure 7 These are photographs of illumination patterns of light irradiated on a screen when the screen is arranged at a distance of 2 m from the lighting device 1 , wherein (a) is a case where the lighting device 1 of the embodiment is used, and (b) is a case where a lighting device of a comparative method is used.

[0088] like Figure 7 As shown in the photos, Figure 7 In the case of comparison method (b), the surrounding contour is blurred. Figure 7 In the case of the implementation method (a), the surrounding contour is clearer than that of the comparison method.

[0089] As described above, in the comparative method, the outline of the illumination range is blurred compared to the embodiment. This is considered to be because the gap between adjacent lens units 40 is wide and the straightness is low, so scattered light is easily generated. Therefore, in such a comparative method, when it is desired to make the outline of the illumination range clear, an aperture or the like is configured.

[0090] (No need to adjust focus)

[0091] However, in the embodiment, since the gap D between adjacent lens units 40 is narrow and the straightness is high, the ridgeline of each lens of the fly-eye lens is clear.

[0092] Therefore, it is difficult to generate scattered light and the outline of the illumination range is clear. Therefore, it is not necessary to set an aperture, nor is it necessary to use a focusing lens to image the outline. Therefore, it is possible to reduce the weight of the portable lighting device 1 and reduce costs.

[0093] (Divergence angle)

[0094] In the embodiment, the irradiated light of the portable lighting device 1 is rectangular, and preferably the divergence angle of the irradiated light is 30° to 45° horizontally and 20° to 30° vertically.

[0095] The effective visual field of human beings, who have excellent information reception ability, is 30° horizontally and 20° vertically. However, considering individual differences and checking the visual field while scanning, the divergence angle design values ​​are set wider than the values ​​to 40° horizontally and 27° vertically based on 30° horizontally and 20° vertically in the embodiment.

[0096] In the embodiment, since the irradiation light is in a rectangular pattern of 40° horizontally and 27° vertically as described above, the effective visual field and the irradiation range that humans can process as a visual field in their brains are roughly consistent. This can form effective lighting for security operations and search activities.

[0097] It should be noted that the preferred ranges of the divergence angle of the irradiation light of the embodiment, namely 30° to 45° horizontally and 20° to 30° vertically, are preferred ranges in a stationary state where there is no movement, such as abnormality detection of a structure.

[0098] On the other hand, when the object to be confirmed is moving relative to the surroundings, a wider irradiation range of 40° to 90° is preferred. A method for this case will be described later.

[0099] (Manufacturing of Fly-Eye Lens 4)

[0100] When manufacturing the fly-eye lens 4, first, the refractive index is determined by the desired divergence angle and the material used. After the refractive index is determined, the desired combination of the curvature radius R, lens size, and axial thickness of the fly-eye lens 4 is determined, and the shape of the fly-eye lens 4 can be determined while maintaining a proportional relationship.

[0101] Then, a mold is prepared in which the inter-lens gap of the lens unit 40 is 10 μm or less, and the fly-eye lens 4 is formed by a glass molding device.

[0102] It should be noted that, Figure 8 This is a table showing examples of the curvature radius R, lens size, and axial thickness of the lens unit of portable lighting devices of different sizes when made of the same material as the portable lighting device 1 of the embodiment. The center of the table is the embodiment, and the upper and lower parts are deformation mode A and deformation mode B.

[0103] (Test results)

[0104] Fig. 9 1 is a diagram showing a simulation result of the irradiation range of light irradiated onto a screen 4 m forward from the portable lighting device 1 according to the embodiment. Fig.10 It is shown Fig. 9 A graph of the measured results of the illumination in the X direction.

[0105] like Fig. 9 As shown, the irradiation range of the light irradiated on the screen 4 m forward from the portable lighting device 1 of the embodiment is 3200 mm in width and 2.1 m in length, forming a 6×4 substantially rectangular shape similar to the lens unit 40 .

[0106] In addition, Fig.10 As shown in FIG. 1 , for the light irradiated on the screen 4 m forward from the portable lighting device 1, the light intensity starts to decrease at a position about 1600 mm from the center in the X direction, and it can be obtained that Fig. 9 The simulation results shown are half of the 3200m width, i.e., the value according to the design value.

[0107] According to the implementation method, Fig.10 As shown, when the range of about 70% or more when the maximum value of the illuminance is 100% is set as the main irradiation range P, the range from about 5% of the maximum value of the illuminance to the width X1 of the main irradiation range P is about 300 mm. Since half of the width of the main irradiation range P is 1600 mm in the embodiment, the range from 5% of the maximum value of the illuminance to the width X1 of the main irradiation range P is about 19% of the width of the main irradiation range P, which is within 20%.

[0108] (Effects of Embodiments)

[0109] (Based on the effect of the small size of the lens unit 40)

[0110] In the portable lighting device 1 of the embodiment, the size of the lens unit 40 is 330 μm×220 μm. The smaller the size of the lens unit 40, the higher the homogenization effect. Therefore, according to the embodiment, the size of one lens unit 40 is small as described above, so even if it is mounted on a small device such as the portable lighting device 1, the emitted light can be sufficiently homogenized.

[0111] In addition, since the size of the lens unit 40 is small, more lens units 40 can be arranged within a limited range. By increasing the number of lens units 40, the illumination of the irradiated light can be uniformed.

[0112] (Visibility Improved)

[0113] In this way, the portable lighting device 1 has a high uniformity of illumination within the irradiation range. Here, in response to the brightness and darkness in the field of vision, the so-called "adaptation" is performed while switching the size of the pupil and the cells that sense light while responding to the change in brightness. The reaction of adapting from a darker place to a brighter place is light adaptation. The reaction of adapting from a brighter place to a darker place is dark adaptation. In the case where light adaptation is required, it becomes a state where the field of vision is not visible until the adaptation is completed. In the case where dark adaptation is required, it becomes a state where the field of vision is not visible until the adaptation is completed.

[0114] Light adaptation can react quickly, while dark adaptation takes 0.1 to 1 second to adapt to the 5-fold difference in darkness. In addition, it is uncomfortable when the need changes more quickly. That is, when there is a distribution of brightness 5 times or more in the field of view, if you want to check every corner, you need to adapt to the field of view you want to check, so it becomes a task that you do unconsciously while feeling uncomfortable. In particular, since dark adaptation is slow, the adaptation of brighter parts in the same field of view is prioritized, resulting in the inability to see parts with lower illumination. If this situation is considered in the case of security operations and search activities where confirmation behavior is related to human life and profit and loss, it is expected that confirmation without omissions can be carried out in a shorter time.

[0115] Since the illumination is uniform in the embodiment, it is not necessary to adapt the eyes. Thus, the user's visibility can be improved. Thus, by avoiding the need for dark adaptation in the visual field, a more reliable and easy confirmation activity can be performed.

[0116] In addition, if the illumination in the irradiation range is uniform, the illumination in the central part is not particularly high compared to other areas in the irradiation range, so the central part does not feel particularly dazzling. Therefore, when irradiating a person, it is possible to ensure that the person being irradiated does not feel dazzling and can clearly confirm the existence of the person.

[0117] (No pressure)

[0118] In addition, if the entire field of view has the same brightness, you can observe the entire range with an adaptive response, so you don't feel stressed.

[0119] Furthermore, when visual work is possible in a dark-adapted state, the appearance of the visual field can be reliably confirmed even under overall low illumination.

[0120] (The width d of the gap is small)

[0121] In the embodiment, the width d between the lens effective portion of one lens unit 40 and the lens effective portion of another lens unit 40, that is, the width d of the lens ineffective portion is 10 μm or less, which is much smaller than 50 μm in the comparative embodiment.

[0122] (Straightness)

[0123] In an embodiment, Figure 3 As shown in FIG. 1 , when the direction in which the lens units 40 are arranged is set to the XY direction, for example, the position of the gap D extending in the X direction between the adjacent lens units 40 and the lens units 40 in the Y direction is in the range of about -1.0 to +0.5 μm. That is, the amplitude m of the position in the Y direction is 1.5 μm. That is, the straightness of the gap D between the adjacent lens units 40 is high.

[0124] (No need to adjust focus)

[0125] As described above, in the embodiment, since the gap D between adjacent lens units 40 is narrow and the straightness is high, the ridgeline of each lens of the fly-eye lens is clear.

[0126] Therefore, compared with the comparative embodiment, the generation of scattered light due to the influence of the gap D of the fly-eye lens 4 is suppressed to be very small. As a result, the illuminance of the outermost peripheral portion of the irradiation light of the portable lighting device 1 can be sharply reduced.

[0127] In this way, since scattered light is less likely to be generated, the outline of the illumination range is clear, so there is no need to set an aperture, nor is there a need for a focusing lens to image the outline. As a result, the portable lighting device 1 can be made lighter and the cost can be reduced. In addition, the outline of the illumination range can be clearly confirmed with the eyes, so that it can be used as a lighting with high energy utilization efficiency.

[0128] By drastically reducing the illumination at the outermost part of the irradiation range, only the face of the person opposite can be illuminated downward, thereby ensuring that the person opposite does not feel dazzled and can clearly confirm the presence of the person.

[0129] In addition, when used for lighting signs and billboards, the visibility of the illuminated object is improved, and at the same time, there is almost no light irradiated outside the illuminated object, which helps to reduce light damage by reducing light leakage and improve energy utilization efficiency.

[0130] Furthermore, by expanding the range of infrared light utilization, for example, by achieving uniform light distribution within the field of view of an infrared camera, even cameras with a small dynamic range will not cause halos, and high-resolution images can be obtained.

[0131] By expanding the scope of ultraviolet light utilization, for example, uniform sterilization, exposure in industrial applications, and uniform UV illumination in bonding processes can be achieved with a simple optical system. In particular, since ultraviolet light deteriorates the irradiated object, it is possible to prevent deterioration around the irradiated area in a clear irradiated area.

[0132] The preferred embodiments of the present invention have been described above, but the present invention is not limited thereto. Fig.11 This is a diagram of a lens unit 40 for explaining a modified form C of the embodiment, and is a diagram showing a case where the arrangement of the lens units 40 is set to a uniform 6-sided dense arrangement shape. As shown in the figure, by setting the arrangement of the lens units 40 to a 6-sided dense arrangement, the irradiation range can be set to a hexagon.

[0133] (Second Embodiment)

[0134] Fig.12 1 is a schematic diagram showing a basic optical system of a portable lighting device 201 according to the second embodiment. The portable lighting device 201 is a small portable lighting device 201 such as a flashlight, similar to the first embodiment.

[0135] The portable lighting device 201 includes a light source 2, a collimator 3, a fly-eye lens 4, and a cover plate 5 in order in the optical axis direction, and these components are held in a housing 10. In addition, a battery storage portion 6 for supplying power to the light source 2 is provided in the housing 10.

[0136] The second embodiment is different from the first embodiment in that the portable lighting device 201 further includes a zoom lens 210 on the inner side of the cover plate 5 in the optical axis direction. Other than this, the second embodiment is the same as the first embodiment, and the description of the same parts as the first embodiment will be omitted.

[0137] The zoom lens 210 is, for example, a single concave lens made of optical glass BK7 with a curvature radius R=-25 mm. The zoom lens 210 can move in the optical axis direction, thereby changing the relative distance with respect to the fly-eye lens 4 in the optical axis direction.

[0138] As described in the first embodiment, the divergence angle of the irradiated light is in the range of 30° to 45° horizontally and 20° to 30° vertically, which is a preferred range for stationary abnormality detection such as abnormality detection of a non-moving object, for example, a structure.

[0139] On the other hand, when the object to be confirmed moves relative to the surroundings, a wider irradiation range is required, and a divergence angle in the range of 40° to 90° is preferred.

[0140] In the second embodiment, the zoom lens 210 can move in the optical axis direction, and by moving in the optical axis direction, the relative distance to the fly-eye lens 4 is changed, so that the divergence angle can be changed within the range of 40° to 90°.

[0141] Fig.13 (b) to (d) show the Fig.12The simulation results of the illumination pattern on the screen 4 meters in front are shown when the distance L between the outer surface of the fly-eye lens 4 on the center of the optical axis and the inner surface of the zoom lens 210 is changed in the range of 5 to 50 mm.

[0142] It should be noted that, Fig.13 (a) shows the simulation result of the irradiation pattern in the first embodiment which does not include the zoom lens 210 as a comparison.

[0143] When the irradiation range is set to a range that is 20% or more of the maximum light intensity in the irradiation mode, the horizontal dimension of the irradiation range on the screen 4 meters in front is Fig.13 In the case of the first embodiment without a zoom lens shown in (a), it is 3200 mm. It should be noted that 20% of the maximum light quantity is set by 5 times the light quantity difference that requires adaptive response.

[0144] In the portable lighting device 201 of the second embodiment, if the distance L between the fly-eye lens 4 and the zoom lens 210 is changed to 5 mm, 20 mm, and 50 mm, the horizontal dimension of the irradiation range is expanded to 400 mm, 5200 mm, and 7500 mm.

[0145] If converted into a viewing angle, in the case of the portable lighting device 1 without a zoom lens in the first embodiment, the divergence angle is 40°. If the distance L is changed to 5 mm, 20 mm, and 50 mm in the portable lighting device 201 in the second embodiment, the divergence angle is expanded to 53°, 66°, and 86°, respectively.

[0146] According to the second embodiment, since the divergence angle can be expanded in this way, when the object to be confirmed moves relative to the surroundings, the irradiation range of the light can be expanded. Thus, the irradiation range suitable for the situation can be obtained.

Claims

1. A portable lighting device, comprising: light source; a collimator for incident light from the light source; and A fly-eye lens for incident light passing through the collimator, comprising a plurality of lens units arranged two-dimensionally on the incident side of the light, and a plurality of lens units arranged two-dimensionally on the exit side in a manner opposite to each of the lens units on the incident side, The size of one side of each of the lens units on the incident side and the exit side is 500 μm or less, the distance between the lens effective portion of one lens unit and the lens effective portion of another lens unit between adjacent lens units is 10 μm or less, and the position deviation of the gap between the lens units arranged in a row and the lens units arranged in a row adjacent to the row in a direction orthogonal to the direction in which the rows are arranged is 3 μm or less, The portable lighting device is configured such that, at a position illuminated by light emitted from the portable lighting device, when a range where the illumination is 75% or more of the maximum value is set as a main illumination range, a range where the illumination is 5% of the maximum value to a width of the main illumination range is within 20% of the width of the main illumination range, Each lens unit is rectangular or hexagonal, and the illumination shape is rectangular or hexagonal.

2. The portable lighting device according to claim 1, wherein: No member functioning as an aperture is included on the light emitting side of the light source.

3. The portable lighting device according to claim 1, wherein: The main irradiation range is a rectangle, and the divergence angle of one side of the rectangle is 30° to 45°, and the divergence angle of the other side is 20° to 30°.

4. The portable lighting device according to any one of claims 1 to 3, wherein: No optical component for applying an optical effect to the light formed by the fly-eye lens is included on the light emitting side of the fly-eye lens.

5. The portable lighting device according to any one of claims 1 to 3, wherein: The fly-eye lens does not include an optical component for shaping or homogenizing light on the light exit side.

6. The portable lighting device according to any one of claims 1 to 3, wherein: The light source, the collimator, and the fly-eye lens are held in a housing. A dust cover is disposed on the light emitting side of the fly-eye lens in the housing.

7. The portable lighting device according to any one of claims 1 to 3, wherein: The light emitting side of the fly-eye lens includes a lens whose distance from the light source is variable. It has a zoom function that can expand the divergence angle by changing the distance between the lens and the light source. Through the zoom function, the divergence angle can be adjusted within a range of 40° to 90°.

8. The portable lighting device according to claim 7, wherein: As the above-mentioned zoom function operates, the illumination changes.

9. The portable lighting device according to any one of claims 1 to 3, wherein: The light source is a light source that generates visible light, infrared light or ultraviolet light.

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