JP2002231002A - Lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device of low power consumption which can be structured at low cost and can irradiate enough amount of light. SOLUTION: The lighting device 10 includes a top part 12a as a second lens face, a rear end face 12c, an outer periphery 12b of a cylindrical shape, a ceiling part 12e as a first lens face formed toward front from the rear end face, a bulk lens 12 having a recessed part 12d consisting of an inner periphery 12f of a cylindrical shape, a light source 11a arranged inside the recessed part 12d, a driving part 13 for driving a light-emitting part, a power source part 14, a switch part 15, and a case 16 containing the bulk lens, the light-emitting part, the driving part, and the power source part, and is so structured that light from the light source enters into an optical medium either from a ceiling part of the recessed part of the bulk lens or the inner periphery, is reflected directly or at the inner face of the outer periphery and then goes outward from the top part along the light axis direction, and at same time, the bulk lens is supported in free movement in the light axis direction against the light- emitting part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a lighting device capable of adjusting a light irradiation range using a small light source such as an ED.

[0002]

2. Description of the Related Art Conventionally, such a lighting device is composed of a light bulb as a light emitting portion and a concave reflecting member provided behind the light source, and reflects light emitted from the light source by the reflecting member. The light is condensed and radiated forward. Then, by moving the reflecting member in the optical axis direction relative to the light source of the light emitting unit, the focal position of the reflecting member is changed with respect to the light source, and the light irradiation range is adjusted. In a lighting device having such a configuration, since a light bulb is used as a light source, power consumption is relatively large, and when a dry battery is used as a power source, the life of the dry battery is relatively short.

On the other hand, a lighting device using, for example, an LED as a light source of a light emitting unit has been developed and has already been put to practical use. A lighting device using such an LED is composed of an LED and a lens disposed in front of the LED, particularly a convex lens. The light emitted from the LED is condensed by the lens, and the light is directed forward. Irradiation.

[0004]

However, in an illumination device using such an LED, all the light emitted from the LED cannot be converged due to the light emission distribution characteristics of the LED. Usage efficiency will be low. For this reason, it is difficult to irradiate a sufficient amount of light.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a lighting device which can be constructed with low power consumption and at low cost and can emit a sufficient amount of light. I have.

[0006]

In order to achieve the above object, a lighting device according to the present invention comprises a top, a bottom, an outer periphery,
It is made of an optical medium having a recess formed by a ceiling portion and an inner peripheral portion formed from a bottom portion to a top portion, wherein the recess portion is a storage portion for a light source, and the ceiling portion is a first lens surface. A bulk lens having a peripheral portion serving as a light incident surface, an outer peripheral portion serving as a total reflection surface, a bottom portion serving as a reflective surface, and a top portion serving as a second lens surface; and a bulk lens disposed in a concave portion of an optical member of the bulk lens. At least one light source, a driving unit that drives the light emitting unit, a power supply unit that supplies power to the driving unit, a switch unit that turns on and off power supply from the power supply unit to the driving unit, a bulk lens, a light source, a driving unit, and And a case accommodating the power supply unit, wherein the bulk lens is supported so as to be movable in the optical axis direction. Preferably, in the lighting device, a first screw portion is integrally provided in a region behind the light source of the bulk lens, and a second screw is attached to the case so as to be screwed to the first screw portion. Is formed, and by rotating the bulk type lens, the bulk type lens is moved in the optical axis direction. More preferably,
The lighting device has a top and a bottom as a second lens surface,
An optical medium having a concave portion including a ceiling portion and an inner peripheral surface as a first lens surface, a light emitting portion including at least one light source disposed in the concave portion of the optical medium, A drive unit for driving the light emitting unit, a power supply unit for supplying power to the drive unit, a switch unit for turning on / off the power supply from the power supply unit to the drive unit, and a case containing the bulk lens, the light emitting unit, the drive unit, and the power supply unit The light from the light source of the light emitting unit is incident on the optical medium from the ceiling or the inner peripheral portion of the concave portion of the optical member, and is reflected directly or on the inner surface of the outer peripheral portion. Are emitted along the optical axis direction, and a bulk lens is supported movably in the optical axis direction with respect to the light emitting unit.

[0007] In the illumination device, preferably, a first screw portion is integrally provided in a region behind the light source of the light emitting portion of the bulk type lens, and is screwed to the first screw portion. A second screw portion is formed in the case, and the bulk lens is moved in the optical axis direction by rotating the bulk lens. In the illumination device, the first screw portion is preferably formed on a rotating ring rotatably mounted on the bulk lens. The lighting device preferably has a third screw portion integrally provided in a region behind the light source of the light emitting portion of the bulk lens, and the light emitting portion is screwed to the third screw portion. A fourth screw portion is formed, and by rotating the bulk type lens relative to the light emitting unit, the bulk type lens is moved in the optical axis direction relative to the light emitting unit. The illumination device preferably includes a reflection member that reflects light from a light source toward a rear end surface of the bulk lens behind the bulk lens. The illuminating device is preferably provided with a reflection mirror for reflecting light emitted from the light source of the bulk lens through the bulk lens in front of the bulk lens.

According to the above configuration, in the bulk type lens used in the illumination device of the present invention, the concave portion serves as a storage portion for the light source.
The ceiling and the top function as lens surfaces, the inner periphery functions as a light incident surface, the outer periphery functions as a total reflection surface, and the bottom functions as a reflection surface. When the light source is housed inside the concave portion, the ceiling functions as the entrance surface of the lens, and the top functions as the exit surface of the lens. Light incident on the optical medium from the inner periphery is either totally reflected or reflected at the bottom and transmitted to the top. The “bulk type” means a solid body having a certain thickness or swelling, such as a shell type, an egg type, a cocoon type, and a kamaboko type. The shape of the cross section perpendicular to the optical axis direction can be a perfect circle, an ellipse, a triangle, a quadrangle, a polygon, or the like. The outer peripheral portion of the bulk-type lens body may be a surface parallel to the optical axis, such as a cylindrical portion or a peripheral portion of a prism, or may have a taper with respect to the optical axis. The ceiling and top lens surfaces are convex, concave,
Either a flat surface or a Fresnel lens surface can be appropriately selected.

The bulk type lens has a lens function and a light transmitting function of connecting the incident surface and the output surface. Therefore, the bulk type lens is a material transparent to the wavelength of light, and has a refractive index equal to that of air. Need to be different. Such materials include:
Transparent resin (transparent plastic material) such as acrylic resin,
Various glass materials such as quartz glass, soda-lime glass, borosilicate glass, and lead glass can be used. Zinc oxide (ZnO), zinc sulfide (ZnS), silicon carbide (Si
A crystalline material such as C) may be used. Further, a material such as a transparent rubber having flexibility, flexibility and elasticity may be used. When an incandescent bulb such as a halogen lamp is used as a light source, a heat-resistant optical material should be used in consideration of heat generated by the bulb. As the heat-resistant optical material, heat-resistant glass such as quartz glass and sapphire glass is preferable. Alternatively, polysulfone resin, polyethersulfone resin,
A heat-resistant optical material such as a polycarbonate resin, a polyetheresteramide resin, a methacrylic resin, an amorphous polyolefin resin, or a heat-resistant resin such as a polymer material having a perfluoroalkyl group can be used. Crystalline materials such as SiC also have excellent heat resistance.

As the light source, a light source which does not generate a remarkable heat generation effect at the time of light emission, such as an LED or a semiconductor laser, is preferable. When an LED or the like is used, when a “light source” is stored in the concave portion (storage portion) of the bulk lens according to the first feature of the present invention, the heat generation action causes
There is no thermal effect on the bulk lens.

If a bulk type lens is used in the lighting device of the present invention, a lighting fixture having a desired illuminance can be easily obtained without requiring a large number of light sources. This illuminance is an illuminance that cannot be achieved by a conventionally known optical system such as a lens if the number of light sources is compared. The present invention
Illuminance that cannot be achieved by the conventional technology can be realized with a simple and small configuration. Although details will be described later, conventional “biconvex lenses”, “plano-convex lenses”, “meniscus convex lenses”, “biconcave lenses”, “plano-concave lenses”, “concave meniscus lenses”
In such a thin lens, a function equivalent to the bulk lens of the present invention cannot be achieved unless a large lens having an infinite diameter is used.

An LED has an internal quantum efficiency and an external quantum efficiency. Generally, the external quantum efficiency is lower than the internal quantum efficiency. By storing the LED in the storage portion (concave portion) of the bulk lens, it is possible to effectively extract the potential LED light energy with an efficiency substantially equal to the internal quantum efficiency. The principle is as follows: (a) reflected light (stray light) at the lens surface at the top and ceiling of the bulk lens and at the outer periphery is hardly scattered outside the bulk lens by being totally reflected at the outer periphery; A) part of the reflected light (stray light) returns to the lens surface that is the top and ceiling, and (c) part of the reflected light (stray light) is reflected at the bottom and returns to the lens surface that is the top and ceiling. (D) a part of the reflected light (stray light) is absorbed by the LED light source and re-emitted, and (e)
It is conceivable that light incident on the inner surface is also guided by total reflection and used effectively.

Further, according to the bulk type lens used in the present invention, the light source itself such as an LED can easily change the optical path such as divergence and convergence of light and change the focus without any modification. It is. That is, if the divergence angle of the light source is known, the selection of the radius of curvature of the first and second curved surfaces and the like can be easily performed. Note that one of the first and second curved surfaces may be a flat surface having a curvature radius of infinity or nearly infinity. If either one of the first and second curved surfaces has a predetermined (finite) radius of curvature that is not infinite, it is possible to control the convergence and divergence of light. The “predetermined divergence angle” may be 0 °, that is, a parallel ray.
Further, even if the divergence angle is 90 °, the light can be effectively condensed because the storage portion completely covers the light emitting portion of the light source optically. This is an operation that is impossible with a conventional optical system such as a lens. That is, the inner peripheral part of the storage part other than the ceiling part can also function as an effective light incident part.

Specifically, the light source used for the bulk type lens is a chip-shaped semiconductor light emitting device, a semiconductor light emitting device molded with a transparent material, or an emission end face of an optical fiber for guiding light from another light source. These light sources may be housed in the housing via an optical medium. By appropriately selecting the optical medium according to the refractive index, it is possible to change the optical path such as divergence and convergence of light, and to change the focal point.Also, it is possible to change the refraction angle of light entering the concave portion from the inner peripheral surface. Thus, total reflection of the concave portion can be made more effective. Here, the optical medium includes not only a solid, a liquid, and a gas, but also a sol-like, colloidal, or gel-like substance that is transparent to the wavelength of light.

Further, the bulk type lens has a top portion,
An optical medium having a bottom portion, an outer peripheral portion, and a concave portion including a ceiling portion and an inner peripheral portion formed from the bottom portion to the top portion, and the concave portion serves as a storage portion for a light source or a photodetector. The part and the top function as a lens surface, the inner peripheral part functions as a light incident surface, the outer peripheral part functions as a total reflection surface, the bottom functions as a reflective surface, and the light incident surface of the inner peripheral part has a predetermined inclination. It is composed of an uneven surface of the size.
The predetermined inclination phi, n ₁ the refractive index of the concave portion, the refractive index of the optical medium n _2, the divergence angle of the total reflection angle theta _t light source in the outer peripheral portion surface of the optical medium as a theta _d, sin ^-1 It is preferable that the angle be determined from {n ₁ / n ₂ cos (θ _d + φ)} = θ _t . For example, even when using an LED such as an edge emitting LED in which most of the emitted light is emitted from the side surface of the chip, all the emitted light can be collected.

Furthermore, since the bulk type lens is formed integrally with the lens portion and the storage portion for storing the light source, the lens and the light source required in the conventional lens system are optically aligned. Since no holding section is required, and no optical alignment step is required, it is only necessary to cover the light source, so that the cost is extremely low.

Accordingly, the drive unit causes one or more light sources to emit light by power supply from the power supply unit, and the light emitted from each light source is partially transmitted to the inner periphery in the concave portion provided in the bulk type lens. The light enters the optical member from the surface, and another part enters the optical medium from the ceiling surface in the concave portion. Part of the light that has entered the optical medium exits directly from the front end face in the optical medium, and another part is reflected inside the outer peripheral surface of the optical member and exits from the front end face. Accordingly, light emitted from the top of the optical medium is refracted based on the lens effect of the first lens surface, which is the ceiling of the optical medium, and the second lens surface, which is the top, and is irradiated forward. .
Further, the Fresnel reflected light generated at the top and the ceiling is totally reflected in the bulk lens and returns to the top to be emitted. Further, the reflected light returned to the LED is absorbed by the PN junction of the LED and re-emitted. As described above, by using the bulk type lens, the irradiation light intensity of the illumination device can be significantly increased.

Here, when the bulk lens is moved in the optical axis direction relative to the light source, the distance from the light source to the first lens surface which is the ceiling of the concave portion of the bulk lens changes. The focal position of the lens constituted by the first lens surface and the second lens surface of the bulk lens moves with respect to the light source. Therefore, the lens effect on the light emitted from the light source changes, and the irradiation range of the light emitted from the top of the bulk lens is adjusted. For example, light emitted from the top of the bulk-type lens is diffused by the lens effect and is applied to a wide angle range, or is condensed by the lens effect and is applied to a narrow angle range.

As described above, according to the present invention, light emitted from a small light source such as an LED as a light source of a light emitting unit is
By using the bulk lens having the special configuration described above, light can be efficiently condensed and a sufficient amount of light can be emitted, and the bulk lens can be moved in the optical axis direction relative to the light source. By moving, the irradiation range of light can be adjusted.

A first screw portion is integrally provided in a region behind the light source of the light emitting portion of the bulk type lens,
If a second screw portion is formed in the case so as to be screwed into the first screw portion, and the bulk lens is moved in the optical axis direction by rotating the bulk lens, the bulk By screwing a first screw portion provided integrally with the lens to a second screw portion formed in the case, the bulk lens moves in the optical axis direction with respect to the case due to rotation of the bulk lens. Therefore, the light-emitting unit moves in the optical axis direction with respect to the light-emitting unit attached to the case. Therefore, the rotation of the bulk-type lens can move and adjust the bulk-type lens with respect to the light emitting unit in the optical axis direction.

When the first screw portion is formed on a rotary ring rotatably mounted on the bulk lens,
Without being limited to the shape of the bulk lens, by screwing a first screw portion formed on a rotating ring rotatably mounted on the bulk lens to a second screw portion formed on the case. Then, the rotating ring rotates and the bulk lens moves in the optical axis direction with respect to the case. At this time, since the bulk type lens itself is rotatably supported by the rotating ring, it moves in the optical axis direction without rotating.

A third screw portion is integrally provided in a region behind the light source of the light emitting portion of the bulk lens, and a fourth screw is attached to the light emitting portion so as to be screwed to the first screw portion. When the bulk lens is rotated in the optical axis direction relative to the light emitting unit by rotating the bulk lens relative to the light emitting unit, the unit is integrated with the bulk lens. The bulk type lens is moved in the optical axis direction with respect to the light emitting unit by screwing a third screw unit provided in the light emitting unit with a fourth screw unit formed in the light emitting unit. Therefore, the bulk lens can be rotated and adjusted in the optical axis direction with respect to the light emitting unit by rotating the bulk lens.

In the case where a reflection member for reflecting light from the light source toward the bottom of the bulk type lens is provided behind the bulk type lens, even if there is no reflection film on the bottom portion, the light source can be used for the bulk type lens. The light leaked backward is reflected by the reflecting member, enters the bulk lens again from the rear end face of the optical member, and is irradiated from the top of the bulk lens. For this reason, the utilization efficiency of the light irradiated forward is further increased, and the illuminance is further improved.

In the case where a reflection mirror for reflecting light emitted from the light source through the bulk type lens is provided in front of the bulk type lens, light emitted from the bulk type lens toward the front is Since the optical axis is bent by being reflected by the reflection mirror, light can be emitted in a desired direction. At this time, by giving a curvature to the surface of the reflecting mirror, the light reflected by the reflecting member can be arbitrarily diffused or focused.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. FIG. 1 is a schematic sectional view of a bulk type lens used in the lighting device of the present invention. As shown in FIG. 1, the bulk-type lens includes a light source 101 such as an LED that emits light in a predetermined wavelength band, and the light source 1.
And at least a bulk type lens 120 completely surrounding the lens. Then, this bulk type lens 120
Are the top 103, the bottom 107, the outer periphery 109, and the bottom 1
07 to the top 103
A light source 101 is disposed in the concave portion 106, and the ceiling 102 serves as a light incident surface of the lens, and the top 10 serves as a light incident surface of the lens.
3 is configured to function as an exit surface of the lens.

The light source 101 shown in FIG.
And a support pin 111 also serving as an electrode on which the LED chip 113 is mounted, an electrode pin 112 for supplying power to the other electrode of the LED chip 113, and a transparent covering the chip 113, the support pin 111 and the electrode pin 112. It is composed of a simple resin mold 114. The side of the resin mold 114 has a cylindrical shape, and the resin mold 114 is fitted to the cylindrical inner peripheral portion 105 of the concave portion 106 of the bulk lens 120 via a spacer 108. The side surface of the resin mold 114 has a cylindrical shape with a diameter (2r) of 2 to 3 mmφ, for example.
The inner peripheral portion 105 of the concave portion 106 of the bulk lens 120 is
For example, it has a cylindrical shape with a diameter of 2.5 to 4 mmφ. In order to fix the LED 101 and the bulk lens 120, the concave portion 1 of the LED 101 and the bulk lens 120 is fixed.
06, a spacer 108 having a thickness of about 0.25 to 0.5 mm is inserted. Spacer 108 is LE
D101 excluding the light emitting portion, that is, LE in FIG.
It is arranged closer to the bottom 107 side than the bottom surface of the D chip 113.

The bulk type lens 120 is, for example,
3 has a convex spherical surface, and the outer peripheral portion 109 has a cylindrical shape. The diameter (2R ₀ ) of the outer peripheral portion 109 is, for example, 10 to 30 mmφ, but can be arbitrarily selected according to the purpose of use. However, in order to further increase the light collection efficiency, it is preferable to satisfy the following relationship: 10r> _R0 > 3r (1). Bulk lens 12
The bulk type lens of the present invention functions even if the diameter (2R ₀ ) of the outer peripheral portion 109 of ₀ is 10 times or more the inner diameter (2r) of the inner peripheral portion 105 of the concave portion 106, but becomes larger than necessary.
It is not preferable for the purpose of miniaturization.

The bulk type lens used in the illuminating device of the present invention can converge at a much lower loss than an optical system using a conventional spherical lens having a convex shape for the following reason. Since an LED is a light source having a large divergence angle, light loss is unavoidable if all the light emitted from the LED is converted into parallel rays by a conventional convex spherical lens. FIG.
FIG. 2A is a view showing the light condensing action of a conventional convex spherical lens. FIG. 2A shows an LED using a convex hemispherical lens.
This shows a state where light from the light source is converted into parallel light. In the figure, the lens has a radius of curvature r and the focal length f from the light source
Has been placed. The focal length of a hemispherical lens is f = r / (n−1), where n is the refractive index of the lens. Therefore, if the refractive index is n = 1.5, f = 2r. Therefore,
As is clear from the figure, the maximum divergence angle that the lens can receive is 30 °, and the light beam shown in FIG. That is, if a conventional lens is used, light having an opening angle or more determined by the relationship between the focal length and the radius of curvature cannot be taken in, so that the loss is large.
Many LED light sources have a divergence angle of 30 ° or more,
In this case, a large loss occurs for the above reason.
Conventionally, such a case is improved by using a high refractive index lens, but the cost is increased. Alternatively, there is an example in which a complex combination of lenses is used, but in this case, the Fresnel reflection loss described below increases.

FIG. 2B is a diagram showing the state of reflection at the entrance surface of a conventional convex hemispherical lens. In the figure,
A line with an arrow represents a light beam emitted from the LED 1 and reflected on the light incident surface of the convex spherical lens. θ (θ ₁ ,
θ ₂ ) represents an emission angle from the LED, that is, a divergence angle.
(Φ ₁ , φ ₂ ) represent the angle of incidence of each light beam on the lens surface. FIG. 3 is a diagram showing Fresnel's law of reflection. In the figure, the horizontal axis represents the angle of incidence of light rays, the vertical axis represents the reflectance of light intensity, and the refractive index of the lens is set to 1.5, and the light rays enter the lens surface from the air.
As is apparent from the figure, the reflectance is low and constant until the incident angle is around 50 °, but the reflectance sharply increases from around 50 °. The light ray having a large incident angle shown in FIG. 2B has a high reflection rate as is clear from the Fresnel reflection law in FIG. For example, when a one-convex spherical lens having a refractive index of 1.5 is used and a parallel light source is formed using a light source having a divergence angle of 30 ° at the focal length of the lens, the loss due to the reflected light is equal to the total light amount. Reach nearly 30%. Therefore, if the lenses are connected in multiple stages as in the conventional optical system, Fresnel reflection occurs in multiple stages, and the loss increases. These reflected lights are scattered into space and cannot be used as convergent light.

On the other hand, in the bulk lens used in the illumination device of the present invention, all the light beams can be incident on the lens surface even if the light beam has a large divergence angle. Since all light beams can be converted into parallel rays, the lens has extremely low loss. Also,
The reflection surface that causes Fresnel reflection is the ceiling 2 and the top 3
Therefore, the reflected light (stray light) reflected on these surfaces is reflected in the bulk lens. These reflected light (stray light)
Does not dissipate outside the bulk-type lens due to total internal reflection at the outer peripheral portion 9, and returns partially to the lens surface that is the top portion 3 and the ceiling portion 2 to become convergent light. The other part is reflected by the bottom 7 and returns to the top 3 or the ceiling 2 to become convergent light. The other part is absorbed by the LED light source, re-emitted, and becomes convergent light.

FIG. 4 is a diagram showing a process in which light returned to the LED light source 101 is re-emitted. In the figure, the returned light is absorbed by the PN junction to generate holes and electrons, and the holes and electrons recombine to emit light again. In particular, this effect is great in an LED having a heterostructure. In the heterostructure LED, the band gap energy of the PN junction, which is the light emitting portion, is higher than the band gap energy of the P and N regions.
Since the reflection light (stray light) is formed to be smaller than the energy, the reflected light (stray light) is not absorbed in the P or N region, but is absorbed only in the PN junction, and emits light again. Furthermore, in the bulk type lens used in the lighting device of the present invention, the inner peripheral portion 10
5 is also guided to the top 103 by total reflection on the outer peripheral surface 109, and is emitted as convergent light. This effect is further enhanced when the LED light source 101 is housed in the housing via an optical medium having a higher refractive index than the optical medium of the bulk lens. In the bulk lens used in the lighting device of the present invention, by the synergistic effect described above,
Since the light of the LED light source is effectively extracted as convergent light with an efficiency substantially equal to the internal quantum efficiency, it is considered that the loss is extremely low as compared with a conventional convex spherical lens.

FIG. 5 is a diagram showing a measurement system for comparing the characteristics when parallel light is produced by a bulk type lens used in the illumination device of the present invention and a conventional convex spherical lens.
FIG. 5A is a schematic diagram showing a measurement system for measuring the light intensity (illuminance) distribution in a direction perpendicular to the optical axis direction when the bulk lens 120 used in the lighting device of the present invention is used. is there. The intensity (illuminance) of the output light from the emission surface of the bulk lens 120 is measured by moving the illuminometer 202 in the y-axis direction with the measurement distance x from the LED 101 being constant. The measurement distance (x) is measured in the optical axis direction. On the other hand, FIG.
It is a figure showing that similar measurement is performed using a conventional biconvex lens.

In the measurements shown in FIGS. 5A and 5B, the outer diameter of the bulk lens 20 according to the first embodiment of the present invention was 30 mmφ, and the biconvex lens 201 used for comparison was used.
Has an outer diameter of 63 mmφ, which is slightly more than twice this. Biconvex lens 2
01 has a focal length of 150 mm,
It was arranged at a position of 150 mm in the x direction from 1. Also, L
The ED light source 101 had a divergence angle of about 12 degrees.

FIG. 6 is a graph comparing the characteristics when parallel light is produced between a bulk lens used in the illumination device of the present invention and a conventional convex spherical lens. Lens 120, conventional thin lens (biconvex lens) 201, and bare L without bulk lens
Intensity (illuminance) of each output light of ED along y direction
The results when the distribution is measured at a measurement distance x = 1 m are shown. Bulk type lens 12 used in lighting device of the present invention
0 indicates that the illuminance is twice that of the conventional thin lens (biconvex lens) 201. This result indicates that the bulk lens used in the lighting device of the present invention has an effect that cannot be realized by the conventional optical system.

FIG. 7 is a diagram showing the evaluation of the parallelism of parallel light formed by a bulk lens used in the illumination device of the present invention and a conventional convex spherical lens. As in FIG. 5, data obtained by measuring the intensity (illuminance) distribution along the y direction while changing the measurement distance x is summarized. The horizontal axis of the figure indicates the square of the reciprocal of the measurement distance x, that is, 1 / x ² , and the vertical axis indicates the maximum intensity (peak intensity) at the measurement distance x. As is clear from the figure, in the case of the bulk type lens of the present invention, the measurement points are clearly plotted on the line indicating the inverse square law, that is, 1 / x ² . On the other hand, conventional thin lenses (biconvex lenses)
In the case of 201, it can be seen that it deviates from the inverse square law. This result indicates that the bulk type lens 120 according to the first embodiment of the present invention has sufficient parallelism, and can achieve performance not inferior to that of a conventional lens system.

FIG. 8 is a diagram showing the relationship between the geometric structure of the bulk type lens used in the illumination device of the present invention and the light collection rate.
Here, the “light collection rate” means “± 1 ° from the bulk type lens.
Light amount of output light at a divergence angle within
D) at the angle of divergence within ± 12 ° from D). That is, it is an amount corresponding to the light beam diameter. The radius of curvature R of the top 103, the total length L of the bulk lens, the medium length (the distance between the lens of the top and the ceiling) D, the inner diameter of the storage unit (the inner peripheral system of the concave portion) r, the length of the curvature of the ceiling 102 Δ Was used as a parameter to measure the light collection rate. Here, the sign of Δ is, as shown in FIG.
The case where 2 is concave is defined as negative, and the case of convex is defined as positive.
FIG. 9 is a diagram showing the geometric structure of the manufactured bulk lens of the present invention. From FIG. 8, in order to improve the light collection rate, 0.93 <k (R / L) <1.06 (2) k = 1 / (0.35 · n−0.168) It is experimentally understood that it is preferable to satisfy (3). Here, n is the refractive index of the optical medium that is the material of the bulk lens. Note that the radius Ro of the cylindrical portion of the bulk lens 120 and the radius of curvature R of the top 3 do not necessarily have to be equal.

Next, another bulk type lens used in the lighting device of the present invention will be described. FIG. 10 is a diagram showing the structure of the bulk lens of the present invention in which the ceiling 102 has a convex shape.
In FIG. 10, the bulk type lens 122 is
2 except for the shape of the bulk lens 12 shown in FIG.
It is equivalent to 0. The outer diameter 2Ro of the cylindrical portion of the bulk lens 122 used for the measurement is 15 mmφ, the total length L of the bulk lens is 25 mm, and the distance D between the top and the ceiling is D.
Is 16 mm, the inner diameter r of the storage section 6 is 5.2 mm, and the refractive index n of the bulk lens is 1.54. The radius of curvature R of the top 103 of this bulk lens is 8.25 mm.
The outer diameter of the resin-molded LED 1 used for the measurement is 5 mmφ.

FIGS. 11A to 11C and FIGS.
(C) is a diagram showing the relationship between the height Δ of the convex portion of the ceiling 102 and the beam intensity profile. Illuminance was measured at a distance x = 1 m from the light source. As is clear from the figure, it is understood that the light-collecting characteristics can be obtained even when the ceiling 102 is a convex lens.

As described above, according to the bulk lens used in the lighting device of the present invention, a light beam having a desired irradiation area can be secured as a light beam contributing to illumination without requiring a large number of LEDs. In addition, a desired illuminance can be easily obtained. This illuminance is an illuminance that cannot be achieved by a conventionally known optical system such as a lens. Surprisingly, the illuminance was comparable to that of a slim flashlight using a halogen lamp currently on the market, and could be realized with only one LED. As described above, according to the bulk lens used in the illumination device of the present invention, the illuminance that cannot be realized by the conventional technology can be realized with a simple structure as shown in FIG.

As the material of the bulk type lens 120 used in the lighting device of the present invention, various glass materials such as a transparent plastic material such as an acrylic resin, quartz glass, soda-lime glass, borosilicate glass, and lead glass can be used. is there. Alternatively, a crystalline material such as ZnO, ZnS, or SiC may be used. Further, a material such as sol, gel, sol-gel mixture or transparent rubber having flexibility, flexibility and elasticity may be used. Further, a sol, a gel, a sol-gel mixture, or the like may be used by being stored in a transparent rubber or a flexible transparent plastic material. A transparent plastic material such as an acrylic resin is a material suitable for mass-producing the bulk lens 120. That is, once a mold is formed and molded using the mold, the bulk lens 120 can be easily mass-produced.

Next, a modified example of the bulk lens used in the lighting device of the present invention will be described. Bulk lenses are
It can also be used when using a light source that emits light from the side of the LED chip, such as an edge-emitting LED.
The edge-emitting LED emits light from the side surface of the LED chip.
When the D chip is mounted, the component that is vertically incident on the inner peripheral portion 105 of the bulk lens increases, so that the amount of light that is not totally reflected and scattered outside the bulk lens increases.
The bulk type lens of the modified example is also applicable to such a light source.
Convergent light can be obtained with extremely low loss.

FIG. 13 is a view showing an optical path of a light beam when the inner peripheral portion 105 and the outer peripheral portion 109 of the bulk type lens of the present invention have an inclination. In the drawing, the divergence angle of the light source is θ _d , the inclination angle between the inner peripheral portion 105 and the outer peripheral portion 109 is φ, the total reflection angle of the outer peripheral portion 109 is θ _t , and the incident angle and the refraction angle of the light ray in the inner peripheral portion 105 are θ ₁ and θ ₂ , the refractive index of the optical medium of the bulk lens, and the refractive index of the storage section (recess) 6 are n ₂ and n ₁ . The figure shows a state in which the light beam having the maximum emission angle of the light source, that is, the divergence angle, satisfies the condition of total reflection by setting the inclination angle to φ, and is totally reflected. Inner circumference 105
According to Snell's law of refraction, sin θ ₁ / sin θ ₂ = n ₂ / n ₁ (4) holds between θ ₁ and θ ₂ , and as is clear from the figure, θ _t , φ,
Between _{θ 2, θ t = φ +} θ 2 (5) is satisfied. Also, as is clear from the figure, θ _d ,
The relationship of θ _d = 90 ° − (θ ₁ + φ) (6) holds between θ ₁ and φ. Eliminating θ ₁ and θ ₂ from the above equations (4), (5), and (6), the bulk-type lens becomes the total reflection angle θ
_When the divergence angle of the light source is θ _d , sin ⁻¹ {n ₁ / n ₂ cos (θ _d + φ)} = θ _t (7) is obtained. That is, if the inner peripheral portion 105 and the outer peripheral portion 109 are inclined at an inclination angle φ or more that satisfies the expression (7), for example, when light enters the inner peripheral portion 105 vertically (θ _d = 9)
0 °), it is totally reflected to the top 103 or the bottom 1
Since the light is reflected at 07 and guided to the top 103, converged light can be obtained.

FIG. 14 is a view showing the structure of a bulk type lens according to the above modification. FIG. 14A shows an example in which fine irregularities are provided on the surface of the inner peripheral portion 105 of the bulk lens 120. The unevenness has a tilt angle of φ or more that satisfies at least the expression (7), and the size of the unevenness may be about the light wavelength. Also, the unevenness is caused by the inner peripheral portion 105.
Only needs to be provided in the vicinity of the light source. Such irregularities can be easily formed by polishing the surface of the inner peripheral portion 105 using an abrasive having an appropriate particle diameter. FIG. 14B shows a state in which a light beam emitted almost in the lateral direction is totally reflected in the bulk lens or reflected on the bottom surface 107 and totally reflected on the side wall, and is guided to the top 103. Thus, for example, even when using an LED such as an edge emitting LED in which most of the emitted light is emitted from the side surface of the chip, all the emitted light can be converged. Furthermore, since the lens unit and the storage unit for storing the light source are formed integrally, there is no need for a holding unit for optically aligning and holding the lens and the light source, which is required in the conventional lens system. Also, since no optical alignment step is required and only the light source needs to be covered, the cost is extremely low.

FIGS. 15 and 16 show a first embodiment of a lighting device according to the present invention. 15 and 16, the lighting device 10 includes a light emitting unit 11 and the light emitting unit 11.
A bulk type lens 12 disposed opposite to the light emitting unit 1
A light source 1 for driving the light source 1; a power supply unit 14 for supplying power to the drive unit 13; a switch unit 15 for turning on / off the power supply from the power supply unit 14 to the drive unit 13;
1, an optical member 12, a drive unit 13, a power supply unit 14, and a case 16 containing a switch unit 15.

The light emitting section 11 is accommodated in a case 16, and includes a light source 11a, for example, one LED, an insulating substrate 11b on which the light source 11a is mounted, and a reinforcing cylinder 11c for covering a lead wire of the light source 11a. , Is composed of.
The light source 11a is not limited to an LED, and various light sources such as a semiconductor laser element can be used. A drive portion 13 described later is formed on the surface of the insulating substrate 11b, a terminal portion 11d that contacts the inner surface of the case on a side edge, and a positive electrode of a battery as a power supply contacts the back surface. Contact portions 11e are formed.

The bulk lens 12 is made of a light-transmitting material such as acrylic resin or glass, and has a rear end facing the light emitting portion 11 and a front end facing outward from the case 16. Protruding. Here, the bulk lens 12 has a convex top portion 12a, a cylindrical outer peripheral portion 12b, and a flat rear end surface 12c.
In the vicinity of the center of 2c, there is provided a recess 12d extending forward along the central axis (optical axis). This recess 12d
Has a ceiling 12e and a cylindrical inner peripheral surface 12f. The light source 11a of the light emitting unit 11 is fitted and held in the recess 12d of the bulk lens 12. When viewed from the light emitting unit 11, the ceiling 12e functions as a first lens surface, and the top 12a functions as a second lens surface, so that the bulk lens 12 functions as a lens. Further, the inner peripheral portion 12f is connected to the light source 11a.
Acts as a light incident surface from

The outer peripheral portion 12 b is provided for the light source 1 of the light emitting portion 11.
In a region behind 1a, a first screw portion 12g is provided on the surface. Further, the outer peripheral portion 12b functions as a reflection surface on the inside. In order to improve the function as the reflecting surface, a reflecting member may be provided on the surface of the outer peripheral portion 12b. Similarly, a reflective member may be provided on the surface of the rear end face 12c.

The driving section 13 is formed on the insulating substrate 11b of the light emitting section 11 as described above,
And a driving current is supplied to the light source 11a of the light emitting unit 11. The specific configuration of the driving unit 13 is appropriately selected according to the light source 11a to be used. The power supply unit 14 is housed in a case 16 and, in the illustrated case, includes three batteries 14a arranged in series. The foremost battery 14a has its positive electrode in contact with the contact portion 11e of the insulating substrate 11b of the light emitting portion 11.

As shown in FIG. 17, the switch unit 15 includes a cap 15a detachably attached to the rear end of the case 16, and an annular conductive member 15b fitted in the cap 15a so as to be movable in the axial direction. , A sliding member 15c inserted through the conductive member 15b. The cap 15a is formed of a conductive material, and is configured to be screwed to the rear end of the case 16. The conductive member 1
5b is formed of a conductive material and has a through hole 1 at the center.
5d, and the rear end of the through hole 15d is tapered. The sliding member 15c is inserted through a through hole 15d of the conductive member 15b via an insulating bushing 15e, and its rear end is tapered to correspond to the shape of the rear end of the through hole 15d.

Further, the sliding member 15c has an annular stopper 15f such as an E-ring near its front end. Here, the sliding member 15c is a conductive member 15
b while the sliding member 15c is inserted through the through hole 15d.
Between the stopper 15f and the front end face of the conductive member 15b.
A compression coil spring 17 is interposed. On the contrary,
Similarly, a compression coil spring 18 is interposed between the rear end surface of the conductive member 15b and the inner end surface of the cap 15a. Therefore, with the cap 15a screwed to the rear end of the case 16, the front end of the sliding member 15c is
4 is in contact with the negative pole of the last battery 14a. Then, as shown in FIG. 17A, the cap 15a is
When the screw is sufficiently screwed into the rear end, the cap 15a and the conductive member 15b advance forward, and the compression coil spring 17 is compressed. Thereby, the tapered rear end of the sliding member 15c is connected to the through hole 1 of the conductive member 15b.
The switch is turned off by separating from the 5d tapered rear end.

On the other hand, as shown in FIG. 17B, when the screw of the cap 15a is loosened with respect to the rear end of the case 16, the cap 15a and the conductive member 15b are slightly retracted. At this time, the front end of the sliding member 15 c is held in contact with the negative pole of the battery 14 a at the rearmost part of the power supply unit 14 based on the tension of the compression coil spring 17.
In this way, the tapered rear end of the sliding member 15c contacts the tapered rear end of the through hole 15d of the conductive member 15b, and the switch is turned off. In addition, cap 1
5a is a clip 1 extending along the outer peripheral surface of the case 16 in a state of being screwed into the rear end of the case 16 in the case shown in the figure.
5e.

In the case shown in the figure, the case 16 is formed as a so-called pencil type in an elongated cylindrical shape, and has a light emitting unit 11, an optical member 12, a driving unit 13, and a power supply unit 1.
4 and the switch unit 15 are accommodated. Here, the case 16 is made of a conductive material, and the terminal portion 11d provided on the insulating substrate 11b is in contact with the inner peripheral surface thereof as described above. As a result, the voltage of the battery 14 a of the power supply unit 14 is changed to the switch unit 15 and the case 16.
Is applied to the drive section 13 from the terminal section 11d and the contact section 11e of the insulating substrate 11b of the light emitting section 11. The inner surface of the case 16 has a battery 14
A thin film of a lubricating resin such as, for example, Delrin (trade name) may be provided in order to facilitate the taking in and out of a and to secure insulation.

Further, the case 16 has a second threaded portion 16a formed on the inner peripheral surface of the front region thereof in correspondence with the first threaded portion 12g formed on the outer peripheral portion 12b of the bulk lens 12. An annular groove 16b for receiving an O-ring 19 disposed so as to surround the bulk type lens 12 near the front end, and an annular stopper 16c for further restricting the bulk type lens 12 from moving backward. Have.

Therefore, by rotating the front part of the bulk lens 12 protruding from the front end of the case 16, the first screw part 12g and the second screw part 16a of the case 16 are screwed together. Thus, the bulk lens 12 moves in the axial direction. At this time, the axial movement direction of the bulk lens 12 is determined by the rotation direction of the bulk lens 12. For example, when the first screw portion 12g and the second screw portion 16a of the case 16 are right-handed screws, the bulk-type lens 12 is rotated clockwise around the optical axis so that the bulk-type lens 12 Along the rear (left side in FIG. 16)
Go to Accordingly, the focal position of the lens by the ceiling 12 e and the top 12 a, which are the first lens surface and the second lens surface of the bulk lens 12, is relatively adjusted with respect to the light source 11 a of the light emitting unit 11. .

The lighting device 10 according to this embodiment is configured as described above. When the lighting device 10 is used, first, the switch section 15 is operated, and more specifically, the cap shown in FIG. When the switch 15 is turned on by loosening the switch 15a to the state shown in FIG.
The driving voltage from each battery 14a is supplied to the driving unit 13 on the insulating substrate 11b of the light emitting unit 11 via the switch unit 15 and the case 16, and the driving unit 13 operates to
Drive current is supplied to the light source 11a.

As a result, the light source 11a emits light,
a part of the light emitted from the bulk lens 12
Of the bulk lens 12, and another part of the light enters the bulk lens 12 from the inner peripheral portion 12e of the bulk lens 12 in the recess 12d. At this time, since the light source 11a is fitted into the concave portion 12d of the bulk lens 12, the light incident on the bulk lens 12 ahead of the light source 11a is forward based on the refractive index of the bulk lens 12. The bulk type lens 1 is guided toward the front of the bulk type lens 12 and is reflected by the outer peripheral portion 12 b of the bulk type lens 12.
2 reach the top 12a.

Light incident on the inner peripheral portion 12e of the bulk lens 12 behind the light source 11a is refracted rearward based on the refractive index of the bulk lens 12, and The light exits from the rear end face 12c. If the rear end face 12 is provided with a reflection member, the light is reflected by the reflection member, and is again reflected in the bulk type lens 1.
2, the light enters the optical member 12 from the rear end face 12c and is guided forward.

As a result, the light emitted from the light source 11a, as well as the light traveling to the side and the rear, is also taken into the bulk lens 12, and the bulk lens 12
The light that has entered the inside is guided to the top 12a of the bulk type lens 12, exits forward from the top 12a, and illuminates the object. When the bulk lens 12 is rotated around the optical axis, the movement of the bulk lens 12 is adjusted along the optical axis, so that the bulk lens 12 has a ceiling 12 e as a first lens surface. The focal position of the lens is adjusted with respect to the light source 11a of the light emitting unit 11 by the top 12a serving as the second lens surface.

Accordingly, the lens effect of the bulk lens 12 on the light emitted from the light source 11a changes. Specifically, for example, when the bulk lens 12 moves backward, the light source 11a of the light emitting unit 11 approaches the bulk lens 12, so that the bulk lens 1
The irradiation angle range of the light emitted from 2 is widened. Further, the bulk lens 12 moves forward, the light source 11a of the light emitting unit 11 separates from the bulk lens 12, and the light is narrowed down by the lens effect of the bulk lens 12, so that the light is emitted from the bulk lens 12. The light irradiation angle range becomes narrow.

Thus, the light source 11a of the light emitting section 11
Light, including light emitted laterally or backward, enters the bulk lens 12 with high efficiency, and is diffused or focused by the lens effect of the bulk lens 12,
Illuminate the object. Compared to the case where a conventional optical lens is used, the use of the bulk lens 12 illuminates with significantly brighter illumination light, and the movement of the bulk lens 12 in the optical axis direction causes the illumination angle of the illumination light to be increased. The range is adjusted so that a wider angle range can be illuminated, or a specific object can be illuminated by narrowing down illumination light.

FIG. 18 shows a main part of a second embodiment of the lighting device according to the present invention. In FIG. 18, the illumination device 20 has basically the same configuration as the illumination device 10 shown in FIGS. 15 to 17, except that only the moving mechanism of the bulk lens 12 with respect to the case 16 is different. . That is, in the lighting device 20 shown in FIG. 18, the bulk lens 12 is
6 is movably supported in the optical axis direction.

The rotating ring 21 is used for the bulk type lens 1.
The inner peripheral surface 21a is formed in a cylindrical shape so as to surround the outer peripheral surface 12b of the second. The inner peripheral portion 21a is formed with a second screw portion 16d formed on the outer peripheral surface of the front end of the case 16.
And a circular projection 21c that engages with a circular groove 12h provided in a region behind the light source 11a of the bulk-type lens 12. Thereby, the rotating ring 21 is configured such that the first screw portion 21b is screwed with the second screw portion 16d of the case 16 and the annular protrusion 21c is engaged with the annular groove 12h of the bulk lens 12. , Can be rotated with respect to the optical member 12.

According to the lighting device 20 having such a configuration,
The light source 11a of the light emitting unit 11 is turned on and the rotating ring 21 is rotated in the same manner as the lighting device 10 illustrated in FIGS. Accordingly, the bulk type lens 12 also moves in the optical axis direction with respect to the case 16. Thereby, the irradiation angle range of the light emitted from the top portion 12a of the bulk lens 12 can be changed. At that time, the bulk lens 12
Is rotatably supported by the rotating ring 21 and does not rotate around the optical axis but simply moves in the optical axis direction.

FIG. 19 shows a main part of a third embodiment of the lighting device according to the present invention. In FIG. 19, the illuminating device 30 has basically the same configuration as the illuminating device 10 shown in FIGS. 15 to 17, except that only the moving mechanism of the bulk lens 12 is different. In the illumination device 30 shown in FIG. 19, the bulk lens 12 includes a third screw portion 12i in a region behind the light source 11a located near the ceiling 12e, and the third screw portion 12i is provided. In response to the above, a fourth screw portion 11f is formed on the outer peripheral surface of the reinforcing cylinder 11c of the light emitting portion 11. As a result, the bulk type lens 12 has its third screw portion 12i screwed with the fourth screw portion 11f of the light emitting portion 11, and the rotation of the bulk type lens 12 causes the bulk type lens 12 to move with respect to the light emitting portion 11. It is configured to be movable and adjustable in the optical axis direction.

According to the lighting device 30 having such a configuration,
15 to 17, the light source 11a of the light emitting unit 11 is turned on and the bulk lens 12 is rotated to move the bulk lens 12 in the optical axis direction. . As a result, the movement of the bulk lens 12 in the optical axis direction causes the bulk lens 12 to move.
Can be changed in the irradiation angle range of the light emitted from the top 12a.

FIG. 20 shows a main part of a fourth embodiment of the lighting device according to the present invention. 20, the lighting device 40 has basically the same configuration as the lighting device 10 shown in FIGS. 15 to 17 and includes a reflection mirror 41 and differs only in a moving mechanism of the optical member 12. It has a configuration. The reflection mirror 41 is a concave mirror, and is formed as, for example, a paraboloid of revolution. further,
The bulk-type lens 12 is supported by a support member 43 slidable in the optical axis direction along at least one (two in the illustrated case) guide members 42 fixed to the case 16, and An adjustment screw 44 is provided which extends in the direction and is rotatably supported by the case 16 so as to be screwed to the support member 43. The adjusting screw 44 has an adjusting knob 45 at one end thereof.
Is rotated, the adjustment screw 44 rotates to move the support member 43 in the optical axis direction. Thus, the bulk lens 12 is configured to be movable and adjustable with respect to the light emitting unit 11 in the optical axis direction.

According to the illumination device 40 having such a configuration,
The light source 11a of the light emitting unit 11 is turned on and the adjustment knob 45 is rotated to operate in the same manner as the lighting device 10 shown in FIGS.
Moves in the optical axis direction. Thereby, the bulk type lens 1
The movement in the optical axis direction 2 can change the irradiation angle range of the light emitted from the top 12a of the bulk lens 12 and reflected by the reflection mirror 41.

FIG. 21 shows a main part of a fifth embodiment of the lighting device according to the present invention. In FIG. 21, the lighting device 50 has basically the same configuration as the lighting device 10 shown in FIGS. 15 to 17, and includes a light emitting unit 51 having a plurality of light sources 51a, and a light source 51a. A bulk type lens 52 having a corresponding concave portion, the switch portion 15 is omitted, and the driving portion 13 integrally formed with the light emitting portion 51 can be moved in the optical axis direction in the case 16 instead. Are different in that they have a switch function.

A plurality of the light emitting portions 51 (in the illustrated case,
3) light sources 51a, for example, LEDs, and each light source 51a is provided with a rear end face 52 of a bulk lens 52.
c. further,
The light emitting section 51 is slidably supported in the optical axis direction in the case 16 together with the drive section 13, and includes an operation section 51 b protruding from a hole 16 e provided in the case 16. When the operation unit 51b is moved by hand in the optical axis direction, power supply to the drive unit 13 of the battery 14a of the power supply unit 14 is turned on and off, and each light source 51a of the light emitting unit 51 is moved in the optical axis direction. It is. In this case, the foremost battery 14a of the power supply unit 14 is always urged forward by a spring member (not shown) provided at the rear end of the case 16, so that the battery 14a always contacts the contact portion 11e. It comes into contact. In addition, when the operation unit 51b is moved to the rearmost position in the hole 16e, for example, the electrical contact between the terminal unit 11d and the inner surface of the case 16 is cut off when the power supply by the movement of the light emitting unit 51 and the driving unit 13 is moved. It is done by doing. The bulk type lens 52 is the same as the bulk type lens 12 described above.
, And is different only in that it is fixed to the front end of the case 16 and has a plurality of recesses 52d in the rear end face 52c.

According to the lighting device 50 having such a configuration,
The power supply unit 1 is moved by moving the operation unit 51b forward.
The power supply from the battery of No. 4 to the drive unit 13 is started, and each light source 51a of the light emitting unit 51 moves forward in the optical axis direction along with the movement of the operation unit 51b. Accordingly, the irradiation angle range of the light emitted from the front end face of the bulk lens 52 can be changed by moving the bulk lens 52 in the optical axis direction relative to the light source 51a.

In the above embodiment, only one or three light sources 11a and 51a constituting the light emitting section are used. However, the present invention is not limited to this, and two or four or more light sources may be provided. The good is clear. In the above-described embodiment, the switch unit 15 is provided for turning on / off the power supply from the power supply unit 14 to the driving unit 13 or the light emitting unit 51 is configured to be slidable in the case 16. The present invention is not limited to this, and any type of switch unit may be provided.

Further, in the above embodiment, the front end surface 12a as the first lens surface of the bulk lens 12 is formed as a convex surface, and the inner end surface 12e as the second lens surface is formed as a concave surface. However, the present invention is not limited to this, and the top portion 12a and the ceiling portion 12e may be formed as convex, concave or flat surfaces or Fresnel lens surfaces, respectively. In the above-described embodiment, the outer peripheral portion 12b and the inner peripheral surface 12f of the bulk lens 12 are each formed in a cylindrical shape. However, the present invention is not limited to this. It may also have a taper that tapers forward.

[0073]

As described above, according to the present invention,
The drive unit causes one or a plurality of light sources to emit light by power supply from the power supply unit. As a result, part of the light emitted from each light source of the light emitting unit enters the optical medium from the ceiling of the concave portion of the bulk lens, and another part enters the optical medium from the inner peripheral surface. Therefore, part of the light that has entered the optical medium exits directly from the top in the optical medium, and another part is reflected inside the outer peripheral surface of the bulk lens and exits from the top. Accordingly, light emitted from the top of the bulk lens is refracted based on the lens effect of the first lens surface, which is the ceiling of the bulk lens, and the second lens surface, which is the top, and is irradiated forward. Is done. That is, since the light source of the light emitting unit is fitted into the concave portion of the bulk lens, the light emitted from the light source is converged with high efficiency, and the illuminance of the illumination device can be increased.

Here, when the bulk type lens is moved in the optical axis direction relative to the light emitting unit, the distance from the light source of the light emitting unit to the first lens surface which is the ceiling of the concave portion of the bulk type lens is reduced. Due to the fluctuation, the focal position of the lens constituted by the first lens surface and the second lens surface of the bulk lens moves with respect to the light source. Therefore, the lens effect on the light emitted from the light source changes, and the irradiation range of the light emitted from the top of the bulk lens is adjusted.
For example, light emitted from the top of the bulk lens is diffused by the lens effect and is applied to a wide angle range, or is condensed by the lens effect and is applied to a narrow angle range. As described above, according to the present invention, illumination that can be configured with low power consumption and at low cost and that can irradiate a sufficient amount of light and that can adjust the focal length arbitrarily or appropriately can be performed. An apparatus is provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a bulk lens used in a lighting device of the present invention.

FIG. 2 is a diagram showing a state of loss due to a lens system of the related art.

FIG. 3 is a diagram showing Fresnel reflection.

FIG. 4 is a diagram showing a process in which reflected light (stray light) is re-emitted at the PN junction of the LED.

FIG. 5 is a diagram showing a measurement system used for comparing characteristics between a bulk lens used in the illumination device of the present invention and a conventional lens.

FIG. 6 is a diagram comparing the light-collecting characteristics of a bulk lens used in the illumination device of the present invention and a conventional lens.

FIG. 7 is a diagram comparing the light-collecting characteristics of a bulk lens used in the illumination device of the present invention and a conventional lens.

FIG. 8 is a diagram showing actually measured values of characteristic changes due to differences in the geometric shape of the bulk lens used in the illumination device of the present invention.

FIG. 9 is a diagram showing a geometric shape of a bulk lens used in the illumination device of the present invention used for the measurement of FIG. 8;

FIG. 10 is a cross-sectional view showing the configuration of another bulk lens used in the lighting device of the present invention.

FIG. 11 is a diagram showing actually measured values of characteristic changes due to differences in the geometric shape of the bulk lens used in the illumination device of the present invention.

FIG. 12 is a diagram showing actually measured values of characteristic changes due to differences in the geometric shape of another bulk type lens used in the illumination device of the present invention.

FIG. 13 is a schematic diagram illustrating a principle according to a modified example of the bulk lens used in the illumination device of the present invention.

FIG. 14 is a diagram showing a configuration of a modified example of the bulk lens used in the lighting device of the present invention.

FIG. 15 is a schematic perspective view showing a configuration of an embodiment of a lighting device according to the present invention.

FIG. 16 is a schematic sectional view showing an internal configuration of the lighting device of FIG. 1;

17A is a diagram illustrating a switch unit in the lighting device of FIG.
It is a partial sectional view showing a state at the time of OFF and at the time of (B) ON.

FIG. 18 is a partial cross-sectional view showing a main part of a second embodiment of the lighting device according to the present invention.

FIG. 19 is a partial sectional view showing a main part of a third embodiment of the lighting device according to the present invention.

FIG. 20 is a partial sectional view showing a main part of a fourth embodiment of the lighting device according to the present invention.

FIG. 21 is a partial sectional view showing a main part of a fifth embodiment of the lighting device according to the present invention.

[Explanation of symbols]

 101, 11a, 51a Light source 102, 12e Ceiling 103, 12a Top 104 Optical medium 105, 12f Inner circumference 106, 12d Concave 107, 12c Bottom, rear end face 108 Spacer 109, 12b Outer circumference 120, 12, 52 Bulk lens Reference Signs List 201 biconvex lens 202 illuminometer 10 lighting device 11 light emitting unit 11b insulating substrate 11c reinforcing cylinder 11d terminal unit 11e contact unit 11f fourth screw unit 12g first screw unit 12h annular groove 12i third screw unit 13 drive unit 14 power supply Part 14a battery 15 switch part 16 case 16a, 16d second screw part 16b annular groove 16c stopper 17, 18 compression coil spring 19 O-ring 20 lighting device 21 rotating ring 21b first screw part 21c annular protrusion 30, 40, 50 lighting Device 41 Reflecting mirror 42 Guide member 43 Support member 44 Adjusting screw 45 Adjusting knob 51 Light emitting unit 51b Operation unit

Claims (18)

[Claims] 1. An optical medium having a top, a bottom, an outer periphery, a recess formed from the bottom toward the top, and a ceiling and an inner periphery, wherein the recess is formed. A storage section for a light source, wherein the ceiling portion is a first lens surface, the inner peripheral portion is a light incident surface, the outer peripheral portion is a total reflection surface, the bottom portion is a reflection surface, and the top portion is a second portion. A bulk lens functioning as a lens surface, at least one light source disposed in a concave portion of the optical member of the bulk lens, a drive unit for driving the light emitting unit, and a power supply unit for supplying power to the drive unit A switch unit for turning on / off the power supply from the power supply unit to the drive unit; and a case accommodating the bulk type lens, the light source, the drive unit, and the power supply unit, wherein the bulk type lens is movable in the optical axis direction. That is supported by A butterfly, a lighting device. 2. A first screw portion is integrally provided in a region behind the light source of the bulk lens, and a second screw is attached to the case so as to be screwed to the first screw portion. The lighting device according to claim 1, wherein a part is formed, and the bulk type lens is moved in an optical axis direction by rotating the bulk type lens. 3. The illumination device according to claim 2, wherein the first screw portion is formed on a rotating ring rotatably mounted on the bulk lens. 4. A third screw portion is integrally provided in a region behind the bulk lens, and a fourth light emitting portion supporting a light source is screwed into the first screw portion. Is formed, and by rotating the bulk-type lens relative to the light-emitting unit, the bulk-type lens is moved in the optical axis direction relative to the light-emitting unit. The lighting device according to claim 1. 5. A reflection member, which is provided behind the light emitting section, for reflecting light from a light source toward a rear end surface of the bulk lens, is provided.
The lighting device according to any one of the above. 6. The mirror according to claim 1, further comprising a reflection mirror provided in front of the bulk lens to reflect light emitted from the light source via the bulk lens. Lighting equipment. 7. The bulk-type lens of the illumination device according to claim 1, wherein an outer diameter of an outer peripheral portion of the optical medium is not less than 3 times and not more than 10 times an inner diameter of the inner peripheral portion. The lighting device according to any one of the preceding claims. 8. The illumination device according to claim 8, wherein the bulk lens is a first lens.
The lighting device according to claim 1, wherein the lens surface is formed as a convex surface. 9. The lighting device according to claim 1, wherein the bulk lens of the lighting device has the first lens surface formed as a concave surface. 10. The bulk-type lens of the illumination device, wherein the first lens surface is formed to be flat.
The lighting device according to claim 1. 11. The lighting device according to claim 1, wherein the bulk lens of the lighting device has the first lens surface formed as a flat Fresnel lens surface. 12. The bulk type lens of the illumination device, wherein R is the radius of curvature of the second lens surface, L is the total length of the bulk type lens measured in the optical axis direction, and n is the refractive index of the bulk type lens. The lighting device according to claim 1, wherein the following relationship is satisfied: 0.93 <k (R / L) <1.06 k = 1 / (0.35 n-0.168). 13. The bulk-type lens of the illumination device, wherein a projection amount of the first lens surface is Δ, and an outer diameter of an outer peripheral portion of the optical medium is 2Ro, wherein 0.025 <Δ / Ro <0.075. The lighting device according to claim 1, wherein the following relationship is satisfied. 14. The lighting device according to claim 1, wherein the bulk lens of the lighting device further includes a rear mirror at a bottom of the optical medium. 15. The illuminating device according to claim 1, wherein the bulk lens of the illuminating device further includes another concave portion arranged inside the optical medium. 16. The lighting device according to claim 1, wherein in the bulk lens of the lighting device, the optical medium has flexibility or bendability. 17. The bulk-type lens of the illumination device, wherein a light incident surface of the inner peripheral portion is formed of a concave and convex surface having a predetermined inclination and having a size of at least a light wavelength or more. Item 2. The lighting device according to Item 1. 18. The predetermined inclination φ is such that the refractive index of the concave portion is n ₁ , the refractive index of the optical medium is n ₂ , the total reflection angle on the outer peripheral surface in the optical medium is θ _t , 18. The lighting device according to claim 17, wherein a divergence angle is θ _d , and the angle is determined from sin ⁻¹ {n ₁ / n ₂ cos (θ _d + φ)} = θ _t .