JP2022102292A - Portable lighting device - Google Patents

Abstract

To provide a portable lighting device having a specific shape in an irradiation range, making illuminance within the irradiation range substantially uniform, and further requiring no focus adjustment from a short distance to a long distance.SOLUTION: A portable lighting device 1 comprises: a light source 2; a collimator 3 into which light of the light source 2 is made incident; a fly-eye lens 4 into which light having passed through the collimator 3 is made incident, and which comprises a plurality of lens cells two-dimensionally arrayed on the incident side of light and a plurality of emission side lens cells two-dimensionally arrayed facing the incident side lens cells, respectively; a cover plate 5; a housing 10; and a battery storage part 6 that supplies power to the light source 2. Each of the plurality of lens cells is rectangular or hexagonal, and their irradiation shapes are rectangular or hexagonal.SELECTED DRAWING: Figure 1

Description

The present invention relates to a portable lighting device.

Conventionally, a portable lighting device has been proposed in which a light irradiation range is made into a specific shape by using a mask having a specific shape, and the illuminance of light in the irradiation range is made substantially uniform by using a lens array (patented). See Document 1).

Japanese Patent No. 4625837

However, in the portable lighting device of the prior art, in order to make the irradiation range a specific shape, an imaging lens in which a mask is placed in an optical path and an image of the mask is formed is used. Therefore, when irradiating light of a specific shape to irradiation positions having different distances from the portable lighting device, it is necessary to move the position of the imaging lens.
An object of the present invention is to provide a portable lighting device having a specific shape in an irradiation range, making the illuminance within the irradiation range substantially uniform, and further requiring no focus adjustment from a short distance to a long distance.

In order to solve the above problems, the present invention is a light source, a collimator to which the light of the light source is incident, and a fly-eye lens to which the light passing through the collimator is incident, and is two-dimensionally arranged on the incident side of the light. A plurality of lens cells and a fly-eye lens including a plurality of lens cells on the exit side arranged two-dimensionally facing each of the lens cells on the incident side, and each lens cell is rectangular or Provided is a portable lighting device that is hexagonal and has a rectangular or hexagonal irradiation shape.

The lens cells on the incident side and the emitted side each have a side size of 500 μm or less, and the distance between the lens effective portion of one lens cell and the lens effective portion of the other lens cell between adjacent lens cells. Is preferably 10 μm or less.

The gap between the lens cells arranged in a row and the lens cells arranged in an adjacent row preferably has a variation in position of 3 μm or less in a direction orthogonal to the direction in which the rows are arranged.

At the position where the light emitted from the portable lighting device is irradiated, when the range of 75% or more of the maximum value of the illuminance is set as the main irradiation range, the illuminance becomes the main irradiation range from 5% of the maximum value. It is preferable that the width up to is within 20% of the width of the main irradiation range.

It is preferable that the main irradiation range is a rectangle, the divergence angle in one side of the rectangle is 30 ° to 45 °, and the divergence angle in the other side is 20 ° to 30 °.

It is preferable that the light emitting side of the fly-eye lens does not include an optical member that applies an optical action to the light formed by the fly-eye lens.

It is preferable that the light emitting side of the fly-eye lens does not include an optical member for molding or homogenizing the light. If the optical member for molding or homogenizing the light is not included, a smaller portable lighting device can be provided.

It is preferable that the light source, the collimator, and the fly-eye lens are held in a housing, and a dustproof cover is arranged on the light emitting side of the fly-eye lens in the housing.

A lens having a variable distance from the light source may be provided on the light emitting side of the fly-eye lens, and may have a zoom function capable of expanding the divergence angle by changing the distance between the lens and the light source. .. By having the zoom function, the irradiation range can be changed, and a portable lighting device more suitable for the application can be provided.

It is preferable that the illuminance changes with the operation of the zoom function.

The light source is preferably a light source that generates visible light, infrared rays, or ultraviolet rays.

According to the present invention, it is possible to provide a portable lighting device having a specific shape in an irradiation range, making the illuminance within the irradiation range substantially uniform, and further requiring no focus adjustment from a short distance to a long distance.

It is a schematic diagram which shows the basic optical system of the portable lighting apparatus 1 of 1st Embodiment. It is a figure explaining the fly eye lens 4, (a) is a front view, (b) is a side view, (c) is an enlarged view of the part A of (b). It is a magnified photograph of the flyeye lens 4, (a) is an embodiment, and (b) is a comparative form. It is a table which shows the axial thickness, the radius of curvature of a lens cell 40, and the rise angle when the fly eye lens 4 is designed by various materials having different refractive indexes. It is an enlarged view of the part B of FIG. 2C, and the solid line in the figure is an embodiment, and the dotted line is a comparative form. It is a graph which measured the straightness of the gap between adjacent lens cells 40. It is a photograph of the illuminance pattern of the light radiated to the screen when the screen is arranged at a position of 2 m from the portable lighting device 1, (a) is the portable lighting device 1 of the embodiment, and (b) is a comparative embodiment. This is the case when the portable lighting device of the above is used. It is a table which shows the radius of curvature R, the lens size, and the axial thickness of the lens cell of the portable lighting apparatus 1 of a different size. It is a figure which showed the simulation result of the irradiation pattern of the light irradiated to the screen 4 m away from the portable lighting apparatus 1 of embodiment. It is a graph which shows the illuminance in the X direction of FIG. It is a figure which shows the lens cell 40 of a deformed form. It is a schematic diagram which shows the basic optical system of the portable lighting apparatus 201 of 2nd Embodiment. (A) shows the simulation result of the irradiation pattern in the first embodiment, and (b) to (d) set the distance L from the outer surface of the fly-eye lens 4 to the inner surface of the zoom lens 210 to 5 to 5. It shows the simulation result of the irradiation pattern on the screen when it changed in the range of 50 mm.

(First Embodiment)
Hereinafter, the portable lighting device 1 according to the first embodiment of the present invention will be described. FIG. 1 is a schematic view showing a basic optical system of the portable lighting device 1 of the first embodiment.

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. There is. Further, a battery accommodating portion 6 for supplying electric power to the light source 2 is provided in the housing 10.

(Light source 2)
The light source 2 is, for example, a light source that generates visible light, infrared rays, ultraviolet rays, or the like, and is a solid-state light source such as a light emitting diode, a lamp, or the like.

(Colrimator 3)
The collimator 3 is a lens or a reflector, and the light emitted from the light source 2 is approximately parallel light. In the embodiment, the collimator 3 is a reflector and a lens, has a cup-shaped mirror surface, and uses reflection and light collection to convert the light emitted from the light source 2 into substantially parallel light in a certain range.

(Cover plate 5)
The cover plate 5 is made of transparent resin and is provided in the opening on the exit side of the housing 10.
The cover plate 5 prevents dust and water from entering the housing, and ensures the durability and environmental resistance of the portable lighting device 1.

(Flyeye lens 4)
2A and 2B are views for explaining the fly-eye lens 4, FIG. 2A is a front view, FIG. 2B is a side view, and FIG. 2C is an enlarged view of a portion A of FIG. 2B. Is. FIG. 3A shows an enlarged photograph of the fly-eye lens 4 of the embodiment, and FIG. 3B shows an enlarged photograph of the fly-eye lens 4'of the comparative embodiment.

(Structure of flyeye lens 4)
As shown in FIG. 2 (c), the fly-eye lens 4 emits light from the collimator 3 so as to face each of the plurality of lens cells 40a two-dimensionally arranged on the incident side and the lens cells 40 on the incident side. A plurality of lens cells 40b arranged two-dimensionally on the side are provided. The lens cell 40a and the lens cell 40b are respectively arranged on both sides of one plate-shaped member and have the same shape, and when it is not necessary to distinguish them, they will be described as the lens cell 40.

In the fly-eye lens 4, the luminous flux is divided by the lens cell 40a on the incident side, and each luminous flux is guided to the irradiation region by the lens cell 40b on the emitting side. Further, the shape of the luminous flux in the irradiation region is a rectangular shape corresponding to the shape of the lens cell 40.
By using the fly-eye lens 4, the uneven brightness of the light source can be dispersed, so that a uniform illuminance distribution can be obtained on the irradiation surface.

(Material of fly eye lens 4)
FIG. 4 shows the axial thickness (μm), the radius of curvature R of the lens cell 40, and the rising edge of the protruding lens cell 40 when the fly-eye lens 4 is designed using various materials having different refractive indexes. It is a table which shows the angle (θ °).
As shown in FIG. 4, the shape of the lens cell 40 changes when the refractive index is different, and the lower the refractive index, the larger the rising angle θ. In the embodiment, VC82 is a low melting point glass having a small rising angle θ as a material of the lens cell 40 (fly eye lens 4) in consideration of ease of mold making by glass molding, mold releasability at the time of molding, and mold durability. Is used.

(Size of fly eye lens 4)
As shown in FIG. 3A, the fly-eye lens 4 of the embodiment is configured by arranging a plurality of rectangular lens cells 40 having an aspect ratio of 6: 4, for example, vertically and horizontally in two dimensions. The fly-eye lens 4 of the embodiment is a so-called micro fly-eye lens having a small size, has a substantially rectangular shape as a whole as shown in FIG. 2A, and has a side size of 10 mm to 30 mm. The form is 20 mm.

(Size of lens cell 40)
The size (pitch) of each lens cell 40 in the fly-eye lens 4 is preferably 500 μm or less, more preferably 400 μm or less, and 330 μm × 220 μm in the embodiment. Assuming that the lens cell 40 is 330 μm wide and 220 μm long and has an aspect ratio of 6: 4, 7300 lens cells are arranged in a luminous flux of Φ26. The size of one side of the lens cell 40 is 1/50 to 1/100 of the size of one side of the fly-eye lens 4 in the embodiment.

(Axial thickness of flyeye lens 4)
As shown in FIG. 2C, the distance (axis) between the apex of the convex portion of the lens cell 40a on the incident side and the apex of the convex portion of the lens cell 40b on the emitting side facing the lens cell 40a on the incident side. The upper thickness) is preferably 1000 μm or less.
In the embodiment, VC82 is used as a material, and as shown in FIG. 4, the axial thickness is 800 μm, and the radius of curvature R of the lens is 344 μm.

(Size of flyeye lens 4 in comparative form)
Hereinafter, a conventional general fly-eye lens will be described as a comparative form.
In the fly-eye lens 4'in the comparative form, as shown in FIG. 3B, a plurality of rectangular lens cells 40', for example, having an aspect ratio of 6: 4, are arranged vertically and horizontally in two dimensions, as in the embodiment. It is composed of.
However, the size of each lens cell 40'of the fly-eye lens 4'in the comparative form is larger than that of the embodiment, and at least one side of the fly-eye lens 4'is 700 μm or more, for example, 1200 μm × 800 μm.
The distance (on-axis thickness) between the apex of the convex portion of the lens cell on the incident side in the comparative form and the apex of the convex portion of the lens cell on the exit side facing the lens cell on the incident side is 5 mm (5,000 μm). Degree.

The lens cell 40'in such a comparative form has been conventionally manufactured as a light source for a projector, and a diffuser plate or a light tunnel is used in combination in the optical system to improve the uniformity of light or to connect the ridgeline of an aperture. It is used to form the edge of the outer circumference of a rectangle by making it an image. Therefore, the size of the lens cell 40'was functionally sufficient even if it was not very small.

(Many arrangements)
However, in a small lighting device such as the portable lighting device 1, the size of the fly-eye lens 4 is as small as 20 mm square, for example. The number of flyeye lenses that can be arranged within this 20 mm square is as small as 448 in the comparative form. On the other hand, in the embodiment, 6600 cells can be arranged.
The number of lens cells 40 also affects the illuminance equalization of the irradiation light, and the larger the number, the more preferable for the illuminance equalization.
According to the embodiment, even if the size of the fly-eye lens 4 is the same, the lens cell 40 can be arranged 10 times or more as compared with the comparative embodiment. Also, the size of the lens cell 40 is small. Therefore, it is possible to reduce the weight and size, and to make the illuminance of the irradiation light uniform and to clarify the edge.

(Width d10 μm or less)
FIG. 5 is an enlarged view of part B in FIG. 2 (c), in which the solid line is an embodiment and the dotted line is a comparative form. In the embodiment, the width d between the lens effective portion of one lens cell 40 and the lens effective portion of the other lens cell 40 between adjacent lens cells 40 in the respective planes on the incident side or the exit side, that is, The width d of the lens ineffective portion is 10 μm or less.
The lens effective portion is a portion that contributes to focusing in the lens cell 40, and the lens non-effective portion is a portion that does not contribute to focusing in the lens cell 40 at the outer peripheral portion of the lens effective portion and diverges or scatters light. Is.
For example, in the comparative form, the width d'is the inflection point P of the line formed by the contour of one lens cell 40'in the cross section passing through the apex of each lens cell 40'shown in FIG. 5, and the lens cell next to it. The width d'(distance) between the contour of 40'and the inflection point P of the line is the width d'(distance), but in the embodiment, the existence of the inflection point P cannot be confirmed, and the width of the portion where the light is scattered is It is 10 μm or less.

(Effect of width d10 μm or less: straightness)
As shown in FIG. 3, FIG. 6 shows the Y of the gap extending in the X direction between the adjacent lens cells 40 and the lens cells 40 in the Y direction, for example, when the direction in which the lens cells 40 are arranged is the XY direction. It is a graph which measured the variation (straightness) of a position in a direction.
The black circles in the figure of FIG. 6 are the straightness of the line C which is the gap D between the lens cells 40 of the fly-eye lens 4 of the embodiment shown in FIG. 3 (a), and the cross marks are the comparisons shown in FIG. 3 (b). It is the straightness of the line C'which is a gap between the lens cells 40' of the fly-eye lens 4'in the form. The position of the gap at the left end of FIG. 6 is set to zero in the Y coordinate, and the position of the gap D in the Y direction when heading to the right by about 1200 μm in the X direction in the figure is plotted.

As shown in the graph, in the comparative form, the position of the gap D'is in the range of about minus 1.0 μm to +5.5 μm. That is, the swing width m'at the position in the Y direction is about 6.5 μm.
On the other hand, in the embodiment, the position of the gap D is in the range of about minus 1.0 to +0.5 μm. That is, the swing width m at the position in the Y direction is 1.5 μm. In the embodiment, the thickness is not limited to 1.5 μm, but may be 3 μm or less, and more preferably 2 μm or less.

FIG. 7 is a photograph of the illuminance pattern of the light emitted to the screen when the screen is arranged at a position 2 m from the portable lighting device 1, and FIG. 7A is a photograph of the portable lighting device 1 of the embodiment, (b). ) Is the case where the portable lighting device of the comparative form is used.

As shown in the photograph of FIG. 7, in the case of the comparative form of FIG. 7 (b), the surrounding contour is blurred. However, in the case of the embodiment of FIG. 7A, the outline of the surroundings is clearer than that of the comparative embodiment.

As described above, in the comparative embodiment, the contour of the illumination range is blurred as compared with the embodiment. It is considered that this is because the width of the gap between the adjacent lens cells 40 is wide and the straightness is low, so that scattered light is likely to be generated. Therefore, in such a comparative form, if it is desired to clarify the outline of the illumination range, an aperture or the like is arranged.

(Focus free)
However, in the embodiment, the gap D between the adjacent lens cells 40 is narrow and the straightness is high, so that the ridgeline of each lens of the fly-eye lens is clear.
Therefore, scattered light is less likely to be generated, and the outline of the illumination range becomes clear. Therefore, it is not necessary to provide an aperture, and there is no need for a focus lens for forming an image of the contour. Therefore, the weight of the portable lighting device 1 can be reduced and the cost can be reduced.

(Divergence angle)
In the embodiment, the irradiation light of the portable lighting device 1 is rectangular, and the divergence angle of the irradiation light is preferably 30 ° to 45 ° in the horizontal direction and 20 ° to 30 ° in the vertical direction.

The effective visual field in which humans have an excellent ability to receive information is horizontal 30 ° and vertical 20 °. However, in consideration of individual differences and confirmation while scanning the field of view, the divergence angle design value is set wider than this in the embodiment while being based on horizontal 30 ° and vertical 20 °. It was set to 40 ° and 27 ° vertically.

In the embodiment, the irradiation light is a rectangular pattern having a width of 40 ° and a height of 27 ° in this way, so that the above-mentioned effective field of view and the irradiation range, which can be collectively processed in the brain by a human as a field of view range, are substantially the same. .. This makes it possible to create lighting that is effective for security work and search activities.

The preferred range of the divergence angle of the irradiation light of the embodiment is 30 ° to 45 ° in the horizontal direction and 20 ° to 30 ° in the vertical direction, which is a preferable range when there is no movement, for example, when the structure is stationary, such as for detecting an abnormality in a structure. Is.
On the other hand, when the object to be confirmed is moving with respect to the surroundings, a wider irradiation range of 40 ° to 90 ° is preferable. The form in this case will be described later.

(Manufacturing of fly eye lens 4)
When manufacturing the flyeye lens 4, the refractive index is first determined from the desired divergence angle and the material used. Once the refractive index is determined, the possible combinations of radius of curvature R, lens size, and axial thickness of the fly-eye lens 4 are determined, and the shape of the fly-eye lens 4 can be determined while maintaining a proportional relationship with each other. Become.
Then, a mold having a lens-to-lens gap of 10 μm or less in the lens cell 40 is manufactured, and the fly-eye lens 4 is molded by a glass molding apparatus.
Note that FIG. 8 is a table showing an example of the radius of curvature R, the lens size, and the axial thickness of the lens cells of the portable lighting devices having different sizes when manufactured from the same material as the portable lighting device 1 of the embodiment. be. The center of the table is the embodiment, and the top and bottom are the modified form A and the modified form B.

(Experimental result)
FIG. 9 is a diagram showing a simulation result of an irradiation range of light irradiated to a screen 4 m away from the portable lighting device 1 of the embodiment. FIG. 10 is a graph showing the actual measurement results of the illuminance in the X direction of FIG.

As shown in FIG. 9, the irradiation range of the light radiated to the screen 4 m ahead of the portable lighting device 1 of the embodiment is 3200 mm in width and 2.1 m in length, and has a substantially rectangular shape of 6 × 4, which is the same as the lens cell 40. It became.
Further, as shown in FIG. 10, the light radiated to the screen 4 m ahead of the portable lighting device 1 starts to fall in the intensity of the light from a position of about 1600 mm in the X direction from the center, and is shown in FIG. The value according to the design value, which is half of the width of 3200 m of the simulation result, was obtained.

According to the embodiment, as shown in FIG. 10, when the range of about 70% or more when the maximum value of illuminance is 100% is set as the main irradiation range P, the illuminance is from about 5% of the maximum value to the main irradiation. The width X1 until the range P is reached is about 300 mm. In the embodiment, half of the width of the main irradiation range P is 1600 mm, so that the width X1 from 5% of the maximum illuminance to the main irradiation range P is about 19% of the width of the main irradiation range P. It is within 20%.

(Effect of embodiment)
(Effect of small size of lens cell 40)
As described above, in the portable lighting device 1 of the embodiment, the size of the lens cell 40 is 330 μm × 220 μm. The smaller the size of the lens cell 40, the better the homogenization effect. Therefore, according to the embodiment, since the size of one lens cell 40 is so small, even if it is mounted on a small device such as a portable lighting device 1, the emitted light can be sufficiently made uniform.

Further, since the size of the lens cell 40 is small, many lens cells 40 can be arranged in a limited range, and even if the number of lens cells 40 is large, the illuminance of the irradiation light can be made uniform. Can be done.

(Improved visibility)
In this way, the portable lighting device 1 has high uniformity of illuminance within the irradiation range.
Here, when dealing with light and darkness in the visual field, so-called "adaptation" is performed, which corresponds to changes in brightness while switching the size of the pupil and the cells that sense light. The reaction of adapting from dark to bright is light adaptation. The reaction of adapting from a bright place to a dark place is dark adaptation. In situations where light adaptation is required, it will be dazzling and invisible until the adaptation is complete. In situations where dark adaptation is required, it will be dark and invisible until the adaptation is complete.

Light adaptation can react quickly, whereas dark adaptation takes 0.1 to 1 second to adapt to a 5x different darkness. And I feel uncomfortable in situations where faster changes are required. In other words, when there is a brightness distribution of 5 times or more in the field of view, if you try to check every corner, an adaptation reaction is required in the field of view you want to check, so you unconsciously feel uncomfortable when working. Become. In particular, since dark adaptation is slow, adaptation to bright areas is prioritized within the same field of view, and as a result, areas with low illuminance cannot be seen. Considering this in situations where confirmation activities such as security work and search activities are related to human life and profit and loss, it is desirable to carry out confirmation that is not overlooked in a shorter time.

In the embodiment, the illuminance is uniform, so that it is not necessary to adjust the eyes. Therefore, the visibility of the user can be improved. In this way, by avoiding the need for dark adaptation in the field of view, it becomes possible to carry out more reliable and easy confirmation activities.
Further, when the illuminance in the irradiation range is uniform, the illuminance in the central portion is not so high as compared with other regions in the irradiation range, so that the central portion 4 does not feel much glare. Therefore, when irradiating a person, it is possible to clearly confirm the existence of the person while ensuring that the irradiated person does not feel glare.

(Stress Free)
Also, if the entire field of view is the same brightness, the entire range can be seen without causing an adaptation reaction. Therefore, I do not feel stress.

Furthermore, if the visual work can be performed in a state where the dark adaptation is completed, the state in the field of view can be surely confirmed even with a low illuminance as a whole.

(Gap width d is small)
In the embodiment, the width d between the lens effective portion of one lens cell 40 and the lens effective portion of the other lens cell 40, that is, the width d of the lens ineffective portion is 10 μm or less, which is compared with 50 μm of the comparative embodiment. It's pretty small.

(Straightness)
In the embodiment, as shown in FIG. 3, when the direction in which the lens cells 40 are lined up is the XY direction, for example, the position of the gap D extending in the X direction between the adjacent lens cells 40 and the lens cells 40 in the Y direction. Is in the range of about minus 1.0 to +0.5 μm. That is, the swing width m at the position in the Y direction is 1.5 μm. That is, the straightness of the gap D between the adjacent lens cells 40 is high.

(Focus free)
As described above, in the embodiment, the gap D between the adjacent lens cells 40 is narrow and the straightness is high, so that the ridgeline of each lens of the fly-eye lens is clear.
Therefore, the generation of scattered light generated by the influence of the gap D of the fly-eye lens 4 can be suppressed to be very small as compared with the comparative form. As a result, the illuminance of the outermost peripheral portion of the irradiation light of the portable lighting device 1 can be sharply reduced.
in this way. Since scattered light is less likely to be generated and the contour of the illumination range becomes clear, it is not necessary to provide an aperture and a focus lens for forming the contour is not required. Therefore, the weight of the portable lighting device 1 can be reduced and the cost can be reduced.
It can be recognized and can be used as lighting with high energy efficiency.

Utilizing the steep decrease in illuminance at the outermost periphery of the irradiation range, it is possible to illuminate only the bottom from the face of the opposite person, and the presence of the person while having the anti-glare effect that the opposite person does not dazzle. Can be clearly confirmed.

In addition, when used for lighting signs and signboards, the visibility of the irradiated object is improved, and at the same time, there is almost no light distributed outside the irradiated object, so light pollution is reduced and energy is reduced by reducing leaked light. Contributes to improving the utilization efficiency of.

Furthermore, by expanding the range of use to infrared rays, for example, it is possible to realize uniform light amount distribution in the field of view of an infrared camera, and even a camera having a small dynamic range can obtain a high-resolution image without causing halation.
By expanding the range of use for ultraviolet rays, for example, in uniform sterilization and industrial applications, it becomes possible to realize uniform UV illuminance in the exposure and bonding steps with a simple optical system. In particular, since ultraviolet rays deteriorate what is irradiated, it is possible to prevent deterioration around the irradiated portion in a clear irradiated area.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited thereto. FIG. 11 is a diagram illustrating the lens cell 40 of the modified form C of the embodiment, and is a diagram showing a case where the arrangement of the lens cells 40 is formed into a uniform hexagonal dense arrangement. As shown in the figure, the irradiation range can be made hexagonal by arranging the lens cells 40 in a hexagonal dense arrangement.

(Second Embodiment)
FIG. 12 is a schematic view showing a basic optical system of the portable lighting device 201 of the second embodiment. The portable lighting device 201 is a small portable lighting device 201 such as a flashlight similar to the first embodiment.
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 are held in a housing 10. Further, a battery accommodating portion 6 for supplying electric power to the light source 2 is provided in the housing 10.
The second embodiment differs from the first embodiment in that the portable lighting device 201 further includes a zoom lens 210 inside the cover plate 5 in the optical axis direction. Since the other parts are the same as those of the first embodiment, the description of the same parts as those of the first embodiment will be omitted.

As an example, the zoom lens 210 is a single-sided concave lens having a radius of curvature R = -25 mm and a material of BK7 made of optical glass. The zoom lens 210 is movable in the optical axis direction, and the relative distance in the optical axis direction with respect to the fly-eye lens 4 can be changed.

As described in the first embodiment, in the range where the emission angle of the irradiation light is 30 ° to 45 ° in the horizontal direction and 20 ° to 30 ° in the vertical direction, there is no movement, for example, a stationary abnormality such as an abnormality detection of a structure. This is a preferable range for detection.
On the other hand, when the object to be confirmed is moving with respect to the surroundings, a wider irradiation range is required, and the divergence angle is preferably in the range of 40 ° to 90 °.

In the second embodiment, the zoom lens 210 is movable in the optical axis direction, and the divergence angle is in the range of 40 ° to 90 ° by changing the relative distance to the flyeye lens 4 by moving in the optical axis direction. It can be changed with.

13 (b) to 13 (d) show the case where the outer surface of the fly-eye lens 4 and the inner surface of the zoom lens 210 and the distance L on the center of the optical axis shown in FIG. 12 are changed in the range of 5 to 50 mm. It shows the simulation result of the irradiation pattern on the screen 4 meters away.
Note that FIG. 13A shows the simulation results of the irradiation pattern in the first embodiment, which does not include the zoom lens 210 for comparison.

When the irradiation range is 20% or more of the maximum amount of light in the irradiation pattern, the horizontal size of the irradiation range on the screen 4 meters away is the case of the first embodiment without the zoom lens shown in FIG. 13 (a). It was 3200 mm. In addition, 20% of the maximum light amount was set from a light amount difference of 5 times, which requires an adaptation reaction.

In the portable lighting device 201 of the second embodiment, when 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 lateral size of the irradiation range is expanded to 400 mm, 5200 mm, and 7500 mm.
In terms of viewing angle, in the case of the portable lighting device 1 without the zoom lens of the first embodiment, the divergence angle is 40 °, and in the portable lighting device 201 of the second embodiment, the distance L is changed to 5 mm, 20 mm, and 50 mm. Then, the divergence angles are expanded to 53 °, 66 °, and 86 °, respectively.

According to the second embodiment, since the divergence angle can be expanded in this way, the irradiation range of light can be expanded when the object to be confirmed is moving with respect to the surroundings. Therefore, it is possible to obtain an irradiation range according to the situation.

1 Portable lighting device 2 Light source 3 Collimator 4 Fly-eye lens 40 Lens cell 40a Incident side lens cell 40b Exit side lens cell

(Focus free)
As described above, in the embodiment, the gap D between the adjacent lens cells 40 is narrow and the straightness is high, so that the ridgeline of each lens of the fly-eye lens is clear.
Therefore, the generation of scattered light generated by the influence of the gap D of the fly-eye lens 4 can be suppressed to be very small as compared with the comparative form. As a result, the illuminance of the outermost peripheral portion of the irradiation light of the portable lighting device 1 can be sharply reduced.
in this way. Since scattered light is less likely to be generated and the contour of the illumination range becomes clear, it is not necessary to provide an aperture and a focus lens for forming the contour is not required. Therefore, the weight of the portable lighting device 1 can be reduced and the cost can be reduced. Then, the outline of the lighting range can be clearly visually recognized, and the lighting can be used as lighting with high energy utilization efficiency.

Claims (11)

Light source and
A collimator to which the light of the light source is incident and
A fly-eye lens into which light that has passed through the collimator is incident, and is two-dimensionally arranged facing each of a plurality of lens cells arranged two-dimensionally on the incident side of the light and the lens cells on the incident side. A fly-eye lens with a plurality of emitting side lens cells, and
A portable lighting device in which each lens cell is rectangular or hexagonal and the irradiation shape is rectangular or hexagonal. The lens cells on the incident side and the emitted side each have a side size of 500 μm or less, and the distance between the lens effective portion of one lens cell and the lens effective portion of the other lens cell between adjacent lens cells. Is 10 μm or less,
The portable lighting device according to claim 1. The gap between the lens cells lined up in a row and the lens cells lined up in a row adjacent to the one row is
The variation in position in the direction orthogonal to the direction in which the rows are lined up is 3 μm or less.
The portable lighting device according to claim 1 or 2. At the position where the light emitted from the portable lighting device is illuminated
When the main irradiation range is the range where the illuminance is 75% or more of the maximum value,
The width from 5% of the maximum illuminance to the main irradiation range is
Within 20% of the width of the main irradiation range,
The portable lighting device according to any one of claims 1 to 3. The main irradiation range is rectangular,
The divergence angle in one side of the rectangle is 30 ° to 45 °.
The divergence angle in the other side is 20 ° to 30 °.
The portable lighting device according to claim 4. The light emitting side of the fly-eye lens does not include an optical member that applies an optical action to the light formed by the fly-eye lens.
The portable lighting device according to any one of claims 1 to 5. The light emitting side of the flyeye lens does not include an optical member for molding or homogenizing the light.
The portable lighting device according to any one of claims 1 to 5. The light source, the collimator, and the flyeye lens are held in the housing.
A dustproof cover is arranged on the light emitting side of the flyeye lens in the housing.
The portable lighting device according to any one of claims 1 to 7. A lens having a variable distance from the light source is provided on the light emitting side of the flyeye lens.
It has a zoom function capable of expanding the divergence angle by changing the distance between the lens and the light source.
The portable lighting device according to any one of claims 1 to 5. The illuminance changes with the operation of the zoom function.
The portable lighting device according to claim 9. The light source is a light source that generates visible light, infrared rays, or ultraviolet rays.
The portable lighting device according to any one of claims 1 to 10.

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