JP2007227968A - Optical information communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aspheric surface lens capable of effectively condensing such as a stray light component of a light source such as LED to obtain a desired illuminance without using a reflecting mirror at the periphery of a lens medium. <P>SOLUTION: A bulk type lens 20 of such as shell type and egg shaped is composed of a bulk type lens medium 4 having a periphery made of an exterior crowning portion 3, bottom portion, and side surface of parallel direction to the optical axis, and housing portion 6 provided in the lens medium 4 from the bottom portion toward the exterior crowning portion 3.A recess top portion 2 and recess sidewall portion 5 of a housing portion 6 installed in the lens medium 4 functions as a first lens surface (2, 5), and the exterior crowning portion 3 of the lens medium 4 functions as a second lens surface 3. In the housing portion 6, a light source 1 or optical detector is stored. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical information communication system using an optical lens having a novel structure, and more particularly to an optical information communication composed of a light emitter and a light receiver using a relatively thick lens using an aspheric surface. About the system.

  Conventionally, spherical lenses such as “biconvex lens”, “planoconvex lens”, “meniscus convex lens”, “biconcave lens”, “planoconcave lens”, “meniscus concave lens” and the like are known. The design theory of these lenses has been established and is technically mature, and there are few proposals for lenses with new structures. Current lens design theory is moving toward the realization of thin lenses as much as possible.

  Recently, slender flashlights using halogen lamps have been put on the market, but the battery life of this type of flashlight is about 3 hours for continuous lighting, and the halogen lamp itself has a short lifespan. Have.

  On the other hand, liquid crystal display devices are frequently used in personal computers, word processors, small portable televisions, vehicle-mounted televisions, and the like. Thus, a fluorescent discharge tube (fluorescent lamp) is used for illumination (backlight) of the liquid crystal display substrate. This fluorescent lamp for backlight has problems that it is easily damaged when its portable television or portable personal computer is dropped, and its characteristics are likely to deteriorate. Further, when used in a low temperature environment such as a cold region in winter, the mercury vapor pressure in the tube is lowered, the luminous efficiency is lowered, and sufficient luminance cannot be obtained. Furthermore, stability and reliability with respect to long-time operation are insufficient. The most important problem is that the power consumption is large. Taking a portable personal computer as an example, the power consumption of the liquid crystal display unit is overwhelmingly larger than the power consumed by the microprocessor and memory. For this reason, when a fluorescent lamp is used as a backlight, it is difficult to operate a portable television or a portable personal computer with a battery for a long time. Further, since the fluorescent lamp emits light in pulses corresponding to the frequency of the power source, there are individual differences, but the problem of eye fatigue arises from the flickering feeling. That is, in the case of a usage method close to direct illumination such as a backlight, there are problems such as eye fatigue due to direct viewing of light from a fluorescent lamp for a long time, or effects on the human body caused by eye fatigue.

  A semiconductor light emitting device such as a light emitting diode (LED) directly converts electric energy into light energy, and thus has a feature that is more efficient than an incandescent bulb such as a halogen lamp or a fluorescent lamp and does not generate heat during light emission. Incandescent bulbs convert electrical energy into thermal energy once, and use the radiation associated with the heat generation. The conversion efficiency is low in principle, and the conversion efficiency to light exceeds 1%. Absent. In the fluorescent lamp, electric energy is converted into discharge energy, and this also has low conversion efficiency. On the other hand, in an LED, the conversion efficiency can be about 20% or more, and a conversion efficiency of about 100 times or more can be easily achieved as compared with an incandescent bulb or a fluorescent lamp. Furthermore, a semiconductor light emitting element such as an LED has a long life that can be considered to be semi-permanent, and there is no problem of flickering like the light of a fluorescent lamp, so that it does not adversely affect the eyes and the human body.

Although the LED has such excellent characteristics, the application of the LED is limited to a very limited range such as a display lamp of a control panel of various devices and a display device such as an electric bulletin board. Patent Document 1 discloses a traffic signal lamp (light-emitting display device) using a plurality of light-emitting diodes for obtaining uniform brightness over the entire front lens and improving visibility. The front lens disclosed in Patent Document 1 has a structure in which a protrusion is provided on the back surface, and a light emitting diode is inserted into a recess surrounded by the protrusion. However, the peripheral surface of the protrusion is tapered, and a reflective film is provided on the tapered peripheral surface. Although this technique tries to obtain uniform brightness by using a reflective film, sufficient illuminance is not obtained. To date, there are few examples where LEDs have been used in lighting fixtures (lighting devices). Recently, some LED application products for illumination of keyholes are known, but they can only illuminate a small area. Except for special cases like this, in general, LEDs have not been used for illumination. Only recently, at the academic level, the intention of LED lighting application has become clear. For example, in the "Akari plan for the 21st century," the Ministry of International Trade and Industry research and development projects, Taguchi professor of Yamaguchi University has been a report to the effect that with a prospect to the practical use of illumination by LED, but using 700 pieces of LED (See Nikkan Kogyo Shimbun on May 26, 2000.)
Japanese Utility Model Publication No. 62-92504

When used for illumination, a large amount of LEDs are used because the light emission area of one LED is a small area of about 1 mm ² even though the luminance of the LED is extremely high. This is because a sufficient luminous flux cannot be obtained. When the conventional optical system is used, the illuminance on the surface to be illuminated does not reach the desired illuminance by light emission of one LED. That is, the luminous flux per unit area on the surface illuminated by light is insufficient.

  Simply, if a lighting fixture in which a large number of LEDs are arranged in a matrix is configured, a constant illuminance will be obtained. However, at present, expensive compound semiconductors are used as the main materials of LEDs, and advanced manufacturing techniques such as epitaxial growth and impurity diffusion are required. Therefore, it is necessary to reduce the manufacturing cost (cost) of LEDs. There are certain limits. Furthermore, there are circumstances peculiar to each semiconductor material, such as an expensive sapphire substrate being used as a substrate for epitaxial growth of gallium nitride (GaN), which is a material of a blue LED.

  Therefore, in order to obtain a desired illuminance, it is not practical to assemble a lighting device (lighting fixture) by a method such as arranging a large number of relatively expensive LEDs. In addition, with silicon (Si), wafers having a diameter of 300 mm have begun to be used, but such large-diameter wafers are not currently available as substrates for epitaxial growth of compound semiconductors, which are LED materials. Further, there are problems in manufacturing technology such as uniformity of epitaxial growth, and it is basically difficult to manufacture an LED having a large light emitting area.

  The present invention has been made to solve the above problems. Accordingly, an object of the present invention is to use a light source such as an LED, and to effectively use a stray light component without using a reflecting mirror, efficiently extract the potential light energy of the light source, and Provides a highly reliable and highly efficient optical information communication system using a bulk-type lens that can easily change the optical path and focus such as light divergence and convergence without any changes to itself. It is to be.

In view of the above object, a first foundation of the present invention relates to a bulk type lens composed of a lens medium having an outer top part, a bottom part and an outer peripheral part, and a storage part provided inside the lens medium. The outer periphery of the lens medium has side surfaces parallel to the optical axis. However, even if a protrusion or a groove is provided on the side surface parallel to the optical axis, the basic surface may be provided in a direction parallel to the optical axis. The storage portion is provided inside the lens medium from the bottom of the lens medium toward the outer top, and has a side wall formed of a plane parallel to the optical axis and a well-shaped recess having a ceiling connected to the side wall. It is. In the bulk type lens according to the first foundation of the present invention, the ceiling part and the side wall part of the storage part (well type concave part) function as the first lens surface, and the outer top part of the lens medium functions as the second lens surface. . A light source or a photodetector is housed inside the housing portion. The bulk type lens according to the first foundation of the present invention has a radius of curvature of the second lens surface as R, a total length measured in the optical axis direction of the lens medium as L, and a refractive index of the lens medium as n.
0.93 <k (R / L) <1.06 (1)
The main point is to satisfy this relationship. However, k in the equation (1) is given by the following equation (2).

k = 1 / (0.35 · n -0.168) (2)
A light source or a light detector is housed in the bulk lens housing section (well-shaped recess) according to the first foundation of the present invention. That is, when the light source is housed inside the housing portion, the first lens surface functions as an entrance surface and the second lens surface functions as an exit surface. On the other hand, when the photodetector is housed inside the housing portion, the second lens surface functions as an entrance surface and the first lens surface functions as an exit surface. “Bulk type” means a lump shape such as a bullet type, egg type, saddle type, saddle type, etc., and is intended to be distinguished from a conventional thin lens. The cross-sectional shape perpendicular to the optical axis direction can be a perfect circle, an ellipse, a triangle, a quadrangle, a polygon, or the like. Therefore, the outer peripheral portion formed of the side surface parallel to the optical axis of the bulk type lens medium may be a cylinder or a prism. The first lens surface is composed of a main incident surface composed of a first curved surface and a side wall incident surface having a curvature different from that of the first curved surface. The first curved surface serving as the main incident surface may be conical. The second lens surface is composed of a second curved surface. As a matter of course, the curvature differs between the second curved surface and the outer peripheral portion of the lens medium connected to the second curved surface.

  Since the lens medium of the bulk type lens according to the first foundation of the present invention functions as an optical transmission unit that connects the incident surface and the output surface, it needs to be a material transparent to the wavelength of light. As the "transparent material", various glass materials such as transparent resin (transparent plastic material) such as acrylic resin, quartz glass, soda-lime glass, borosilicate glass, lead glass, and the like can be used. Alternatively, a crystalline material such as zinc oxide (ZnO), zinc sulfide (ZnS), or silicon carbide (SiC) may be used. Further, a material such as a flexible plastic, a flexible plastic or a transparent rubber may be used. When an incandescent bulb such as a halogen lamp is used as the light source, a heat resistant optical material should be used in consideration of the heat generated by this. As the heat resistant optical material, heat resistant glass such as quartz glass and sapphire glass is preferable. Alternatively, a heat-resistant optical material such as a heat-resistant resin such as a polysulfone resin, a polyether sulfone resin, a polycarbonate resin, a polyetheresteramide resin, a methacrylic resin, an amorphous polyolefin resin, or a polymer material having a perfluoroalkyl group It can be used. Crystalline materials such as SiC are also excellent in heat resistance.

  However, the “light source” is preferably a light source that does not generate a significant heat generation effect when emitting light from an LED or a semiconductor laser. However, since the output light of the semiconductor laser is light having coherent straightness, there is no significant difference in effect between the bulk type lens according to the first basis of the present invention and the conventional thin lens. Therefore, an LED whose output light is not coherent, has dispersion (divergence), and inherently has a tendency to spread the beam, is preferable as the light source of the bulk lens according to the first basis of the present invention. If an LED or the like is used, when the “light source” is housed in the concave portion (housing portion) of the bulk type lens according to the first foundation of the present invention, the thermal effect is exerted on the bulk type lens by the heat generation action. Never give.

  According to the bulk lens according to the first foundation of the present invention, 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. That is, it is possible to realize an illuminance that cannot be predicted by conventional common sense with a simple and small configuration. Although details will be described later, conventional thin lenses such as “biconvex lens”, “planoconvex lens”, “meniscus convex lens”, “biconcave lens”, “planoconcave lens”, “meniscus concave lens”, etc. Unless a lens is used, a function equivalent to the bulk type lens of the present invention cannot be achieved.

  LEDs have an internal quantum efficiency and an external quantum efficiency, but the external quantum efficiency is usually lower than the internal quantum efficiency. The bulk type lens according to the first foundation of the present invention can effectively extract the light energy of the potential LED with the efficiency substantially equal to the internal quantum efficiency by storing the LED in the storage portion (recess). It becomes.

  Further, according to the bulk type lens according to the first basis of the present invention, it is possible to easily change the light path such as light divergence and convergence, or change the focus without changing the light source itself such as the LED. Is possible.

  The “light source” according to the first foundation of the present invention does not need to be a coffee rent, but is preferably a light source that emits light in a specific direction at a predetermined divergence angle of about 10 ° to 20 °. This is because if the divergence angle for emitting light in a specific direction is known, optical design such as condensing and dispersion is facilitated, and selection of the curvature radii of the first and second curved surfaces can be easily performed. It should be noted that either one of the first and second curved surfaces may include a flat surface having an infinite curvature radius or close to infinity. This is because light convergence and divergence can be controlled if either one of the first and second curved surfaces has a predetermined (finite) radius of curvature that is not infinite. In addition, the “predetermined divergence angle” may include 0 °, that is, parallel rays, but in the case of parallel rays, the bulk type lens according to the first basis of the present invention and the conventional thin lens have a remarkable effect. Differences are not allowed. On the other hand, even when the divergence angle is 90 °, since the housing part almost completely optically covers the main light emitting part of the light source, the light is effectively condensed through the concave side wall part (side wall incident surface). Is possible. This is an operation that is impossible with a conventional optical system such as a lens. That is, the side wall incident surface (recessed side wall portion) of the storage unit other than the main incident surface (ceiling portion) made of the first curved surface also constitutes the first lens surface and can function as an effective light incident surface. .

  Specifically, the “light source” according to the first foundation of the present invention is an LED molded with a transparent material having a first refractive index, and the housing portion is a first light source different from the first refractive index. The light source may be housed through a fluid or fluid having a refractive index of 2. Here, “fluid” means a gas or liquid that is transparent to the wavelength of light emitted from a light source, and air can be used most simply. A “fluid” refers to a substance that is transparent to the wavelength of light in the form of sol, colloid, or gel. Alternatively, the “main light emitting part of the light source” in the first basis of the present invention is an end part of an optical fiber having a transmission part made of a transparent material having a first refractive index, and the housing part is the first part. You may make it accommodate the edge part of an optical fiber through the fluid or fluid which has a 2nd refractive index different from a refractive index. In this case, the light source for inputting predetermined light from the other end of the optical fiber is not necessarily limited to the semiconductor light emitting element. This is because even the light from the incandescent bulb can be maintained at a low temperature at the end of the optical fiber housed in the concave portion (housing portion) of the bulk lens.

In the first foundation of the present invention, it is preferable that the outer diameter of the outer peripheral portion of the lens medium is not less than 3 times and not more than 10 times the inner diameter of the storage portion (well-shaped recess). Increasing the ratio of the outer diameter to the inner diameter is equivalent to sufficiently increasing the thickness of the side wall portion of the lens medium storage portion (well-shaped recess). By sufficiently increasing the thickness of the side wall, the stray light component of the light source is effectively condensed without using a structure in which a reflective film is provided on a tapered peripheral surface such as the front lens disclosed in Patent Document 1. I can do it. The “stray light component” means a component of output light incident on a portion other than the ceiling portion (main incident surface) of the storage portion due to the divergence characteristics of the output light of the light source. Since it is not essential to use a reflecting mirror on the outer periphery of the lens medium, it is possible to provide projections, grooves, etc. on the outer periphery to use for holding the bulk lens and driving / controlling its position. . That is, even if other shapes and structures such as protrusions and grooves are added to the outer periphery of the lens medium, the condensing characteristics as a lens are not critically affected.
In the bulk-type lens according to the first aspect of the present invention, the protrusion amount of the first lens surface at the ceiling portion of the storage portion (well-type concave portion) is Δ, and the outer periphery formed of the side surface parallel to the optical axis of the lens medium the outer diameter of the parts as 2r _e,
0.025 <Δ / r _e <0.075 (3)
It is preferable to satisfy this relationship.

  In the bulk-type lens according to the first foundation of the present invention, a storage portion made of another well-shaped recess having a side wall portion formed in a plane parallel to the side wall portion may be arranged in parallel inside the lens medium. good. Further, in the bulk type lens according to the first foundation of the present invention, if the lens medium is made flexible or flexible, the curvature of the outer apex can be arbitrarily changed. The distance can be adjusted.

  The gist of the second foundation of the present invention is that the light emitting body is composed of a bulk type lens defined in the first foundation and a light source housed in a housing portion of the bulk lens.

  In the light emitting body according to the second basis of the present invention, when a semiconductor light emitting element that emits less heat during light emission, particularly an LED, is used, even when the light source is housed inside the concave portion (housing portion) of the bulk lens. The heat generation action is preferable because it does not affect the bulk type lens thermally and can maintain reliability and stability even in long-term operation. Alternatively, in the light emitter according to the second basis of the present invention, the main light emitting portion of the light source has a transmission portion made of a transparent material optically connected to a predetermined primary light source and having a first refractive index. You may comprise as a secondary light source which consists of an edge part of an optical fiber. The storage unit stores the secondary light source (an end portion of the optical fiber) via a fluid or fluid having a second refractive index different from the first refractive index.

According to the light emitter according to the second basis of the present invention, desired illuminance can be easily obtained with a small number of light sources. Moreover, the component of the output light from the light source incident on the part other than the ceiling part (main incident surface) of the storage part is collected almost nearly 100% without structurally using a reflecting mirror on the outer peripheral part or the bottom part of the lens medium. Since the light can be condensed with light efficiency, an extremely bright light emitter can be realized. The illuminance exhibited by the light emitter is an illuminance that cannot be achieved by a conventionally known optical system, and is sufficiently bright that cannot be predicted by conventional common general knowledge. Furthermore, this light emitter has low power consumption and no flicker.
In the second basis of the present invention, it is preferable to further include light source position control / drive means for moving and controlling the position of the light source relative to the lens medium along the optical axis direction. Since the tapered reflective film disclosed in Patent Document 1 is unnecessary, the outer peripheral portion of the bulk lens can have an arbitrary shape. For this reason, the light source position control / driving means having various structures can be configured by using the outer peripheral portion of the bulk type lens. For example, the light source position control / driving means may be configured by providing a spiral protrusion on the outer periphery of the bulk lens and using this as a thread of a male screw.

  The gist of the third foundation of the present invention is that the light receiving body is constituted by a bulk type lens defined in the first foundation and a photodetector housed in a housing portion of the bulk type lens.

  An infrared detector such as a thermopile may be used for the photodetector housed in the bulk lens housing section and applied to temperature detection.

  The gist of the fourth foundation of the present invention is that it is a lighting fixture comprising a light emitter defined in the second foundation and a power source connected to the light source of the light emitter. It is particularly suitable for portable lighting equipment such as a slender flashlight such as a penlight. A battery is preferable as the power source of the portable lighting device. Furthermore, it is also suitable as a medical light for optometry. As the light source of the lighting fixture, a semiconductor light emitting element, particularly an LED, which emits light of a predetermined wavelength by molding a semiconductor chip having electrodes connected to the anode and cathode of the battery with a transparent material is preferable.

  In the luminaire according to the fourth foundation of the present invention, since a single semiconductor light emitting element may be used, the structure is simple and the manufacturing cost can be reduced. Further, the bulk type lens can efficiently extract the potential light energy of the semiconductor light emitting device and obtain sufficient illuminance necessary for illumination. Furthermore, this lighting fixture is excellent in stability and reliability over a long period of time and does not flicker. Furthermore, since the power consumption is small, the battery life is long. In addition, since sufficient brightness as a lighting fixture is obtained, it is applicable also as a display device.

  On the basis of the first to fourth foundations, the present invention is characterized by the first bulk-type lens defined by the first foundation, the light source housed in the housing portion of the first bulk-type lens, The optical information communication system is composed of a second bulk type lens defined on the basis of No. 1 and a light receiver composed of a photodetector housed in a housing portion of the second bulk type lens. The gist. In the optical information communication system according to the feature of the present invention, the ceiling portion and the side wall portion of the first concave portion of the first bulk lens function as the first incident surface, and the first outer top portion functions as the first emission surface. To do. The second outer top portion of the second bulk type lens functions as a second incident surface, and the ceiling portion and the side wall portion of the second concave portion function as a second emission surface.

In the optical information communication system according to the features of the present invention, if a semiconductor light emitting element such as an LED that emits less light during light emission is used, even when a light source is housed inside the concave portion (housing portion) of the bulk lens, The heat generation action is preferable because it does not affect the bulk type lens thermally, and can maintain reliability and stability even in long-term operation. Further, as already described in the second basis, an optical signal can be output with high efficiency. On the other hand, the light receiving body in which the light reaches the photodetector in the reverse process to the light emitting body can detect light with extremely high sensitivity as described in the third basic.
In the feature of the present invention, if a semiconductor light emitting device having the same structure is used for the light source and the photodetector, extremely high sensitivity detection can be performed by the resonance effect of the forbidden bandwidth.

  According to the present invention, it is possible to effectively collect stray light components without using a reflecting mirror at a part of the outer peripheral portion of the lens medium, and it is possible to efficiently extract the potential light energy of the light source. Since the bulk type lens is used, a highly reliable and highly efficient optical information communication system can be provided.

  Next, first to sixth embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(First embodiment)
As shown in FIG. 1, the light emitter according to the first embodiment of the present invention includes at least a light source 1 that emits light of a predetermined wavelength and a bulk lens 20 that almost completely covers the light source 1. ing. The bulk type lens 20 includes a bulk type (bullet type) lens medium 4 having an outer top part (outgoing surface) 3, a bottom part, and an outer peripheral part composed of side surfaces parallel to the optical axis, and an outer top part 3 from the bottom part. And a storage portion 6 formed of a well-shaped concave portion having a side wall portion formed of a surface parallel to the optical axis and provided inside the lens medium 4. The ceiling part (concave part ceiling part) of the recessed part which comprises the accommodating part 6 provided in the inside of the lens medium 4 is the main incident surface (main incident surface of the first lens surface) 2, and the top part (outer top part) of the lens medium 4. Functions as an exit surface (second lens surface) 3. The light source 1 is completely stored in the storage unit 6.

  The first lens surface (2, 5) is composed of a main incident surface 2 formed of a first curved surface and a side wall incident surface 5 having a curvature different from that of the first curved surface. The storage portion 6 includes a concave ceiling portion 2 having a first curved surface, and a concave side wall portion (side wall incident surface) 5 formed continuously from the concave ceiling portion 2 so as to form a concave portion. . The light incident from the main entrance surface 2 is output from the second lens surface 3, that is, the exit surface 3 formed of the second curved surface. Since the portion connecting the main entrance surface 2 and the exit surface 3 of the lens medium 4 functions as an optical transmission unit, it needs to be made of a material that is transparent to the wavelength of light emitted from the light source.

  The light source 1 shown in FIG. 1 includes an LED chip 13 disposed on a base integrally connected to a first pin 11, a sealing resin 14 covering the LED chip 13, and a first pin 11. The resin-molded LED is composed of at least a second pin 12 paired with the LED. As shown in FIG. 1, the top part of the main light emitting part of the resin-molded LED 1 has a convex curved surface. As described above, the vicinity of the top of the sealing resin 14 forms a convex curved surface, so that the light from the LED chip 13 is output in the right direction in FIG. 1 at a predetermined divergence angle.

Except for the curved surface portion of the convex shape, LED1, which is a resin mold, for example, a cylindrical shape with a diameter (outer _diameter) 2r LED = _{2~3mm ^φ.} Side wall portion of the housing part 6 of the bulk-shaped lens 20, such that it accommodates the main light emitting portion of the LED1 that is resin molded, and has a cylindrical shape with a diameter (inner diameter) _2r i = 2.5~4mm ^φ. Although not shown, a spacer having a thickness of about 0.25 to 0.5 mm is provided between the LED 1 and the storage unit 6 of the bulk lens 20 in order to fix the LED 1 and the bulk lens 20. Has been inserted. That is, the outer diameter _{2r LED} of LED1, the inside diameter 2r _i of the storage unit 6 is set substantially identical and slightly, smaller towards the outer diameter _{2r LED} of LED1. The spacer may be disposed at a position excluding the main light emitting portion of the LED 1, that is, on the left side of the bottom surface of the LED chip 13 in FIG. The bulk-type lens 20 has a cylindrical shape that is substantially the same as that of the LED 1 except for the outer top portion 3 having an exit surface that is a convex second curved surface. The diameter (outer diameter) 2r _e cylindrical portion of the bulk-type lens 20 is 10 to 30 mm ^phi. The diameter (outer diameter) 2r _e of the bulk lens 20 can be selected according to the purpose of use of the light emitter according to the first embodiment of the present invention. Accordingly, it may be 10 ^mmφ or less or 30 mm ^φ or more. However, in order to increase the light collection efficiency,
_{10r i> r e> 3r i} ····· (4)
It is preferable to satisfy this relationship. The diameter of the bulk-shaped lens 20 (outside diameter) 2r _e is at least 10 times the internal diameter 2r _i of the receiving portion 6, the bulk lens of the present invention, will function, becomes larger than necessary, and the purpose of downsizing This is not preferable.

  In general, light emitted from places other than the convex curved surface of the sealing resin 14 of the LED 1 becomes a so-called stray light component and does not contribute to illumination. However, in the bulk type lens 20 having a geometrical shape that satisfies the formula (4), the stray light component composed of light emitted from places other than the convex curved surface is effective with a light collection efficiency close to 100%. Can contribute to lighting. That is, the side wall portion (recess side wall portion) 5 of the storage portion 6 other than the main incident surface (recessed ceiling portion) 2 formed of the first curved surface can also function as an effective light incident surface (side wall incident surface). is there. Further, between the LED 1 and the storage unit 6 of the bulk lens 20, light components reflected at the respective interfaces are multiple-reflected and become stray light components. In a conventionally known optical system such as a lens, these stray light components cannot be extracted so as to contribute to illumination. However, these stray light components are also confined inside the storage portion 6 and can be incident through the concave side wall portion (side wall incident surface) 5 in the first embodiment of the present invention. It can be a component that can contribute to illumination. By designing the geometric structure with a sufficiently thick side wall so as to satisfy the formula (4), the light input from the concave side wall 5 is bulky without using a reflecting mirror on the outer periphery. It is possible to prevent output (leakage) from the outer periphery of the mold lens 20 as it is. Of course, the light vertically incident on the recess side wall 5 will leak from the outer periphery. However, light incident on the concave sidewall 5 at a certain incident angle is refracted at a refraction angle determined by Snell's law. As the thickness of the lens medium 4 located on the side wall portion of the storage portion 6 increases, the component leaking from the outer periphery of the lens medium 4 decreases. And if it becomes the geometrical shape which satisfies (4) Formula, it will be considered that the component which leaks from the outer peripheral part of the lens medium 4 becomes almost negligible. In particular, in a resin-sealed LED, there is little component perpendicularly incident on the concave portion side wall portion 5 in the light emitted from places other than the convex curved surface, so that the geometric shape satisfying the equation (4) is obtained. In this case, it is considered that the component leaking from the outer peripheral portion of the lens medium 4 can be almost ignored. As a result, the light energy of the potential LED chip 13 is effectively used with an efficiency close to the internal quantum efficiency without depending on the light extraction efficiency such as the shape of the sealing resin 14 and the reflection components between the optical systems. Can be taken out.

  FIG. 2A shows a measurement system for measuring the light intensity (illuminance) distribution in the direction perpendicular to the optical axis direction when the bulk lens 20 according to the first embodiment of the present invention is used. It is a schematic diagram shown. The intensity (illuminance) of the output light from the exit surface of the bulk lens 20 is measured by moving the illuminometer 102 in the y-axis direction with the measurement distance x from the LED 1 being constant. The measurement distance (x) is measured in the optical axis direction. On the other hand, FIG. 2B is a diagram showing a configuration in a case where the same measurement is performed using a conventional thin lens (biconvex lens) 101. In the measurements shown in FIGS. 2A and 2B, the outer diameter of the bulk lens 20 according to the first embodiment of the present invention is 30 mmφ, and the conventional thin lens (biconvex lens) used for comparison is used. ) The outer diameter of 101 was set to 63 mmφ, which is more than twice this. As will be understood from the following description, even if the outer diameter of the thin lens 101 is made slightly larger than twice, it is possible to obtain the same optical characteristics as those of the bulk lens 20 according to the first embodiment of the present invention. I can't. The thin lens 101 has a focal length of 190 mm, and is arranged at a position 150 mm from the LED 1 in the x direction. Further, in the conventional optical system shown in FIG. 2B, in addition to the illustrated tools, additional tools such as a lens holder and a driving device are necessary, and adjustment is complicated, but FIG. In the bulk type lens 20 according to the first embodiment of the present invention, the optical path can be expanded and converged with a simple configuration.

  FIG. 3 shows the intensity (illuminance) distribution along the y direction of the output light of each of the bulk type lens 20, the thin lens 101, and the bare LED that does not use the bulk type lens according to the first embodiment of the present invention. It is a figure which shows the result at the time of measuring in measurement distance x = 1m. It can be seen that the bulk lens 20 according to the first embodiment of the present invention can obtain twice as much illuminance as the thin lens 101.

FIG. 4 summarizes data obtained by measuring the intensity (illuminance) distribution along the y direction similar to FIG. 3 while changing the measurement distance x. The horizontal axis in FIG. 4 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 shown in FIG. 4, for bulk lens 20 according to the first embodiment of the present invention, the inverse square law, i.e. clean measuring points on a line indicating the 1 / x ² are plotted. On the other hand, the thin lens 101 is shown to deviate from the inverse square law. That is, in the case of the bulk lens 20 according to the first embodiment of the present invention, the parallelism of the beam of the output light is good, but in the case of the thin lens 101, since the beam is not parallel, the inverse square is obtained. It turns out that it is off the law. This is the same even if a biconvex lens with another focal length is used and the distance between the LED 1 and the thin lens 101 is changed. Although it may be possible if a biconvex lens having an infinite diameter is used, the first embodiment of the present invention can be realized with a compact arrangement as shown in FIG. It is impossible to obtain the same result as that of the bulk lens 20 according to the above. From simple geometrical optics, the conventional thin lens 101 cannot bring the thin lens 101 closer to the LED 1 without using a convex lens having a very small focal length as used in a microscope. However, when the thin lens 101 is brought closer to the LED 1 in this way, the light collection efficiency is lowered. If a large short focus lens is prepared in order to improve the light collection efficiency, the lens becomes thick and large, so that the distance between the LED 1 and the center of the thin lens 101 cannot be substantially shortened. After all, it can be concluded that an extremely large and complicated optical system is necessary to obtain the same result as that of the bulk lens 20 according to the first embodiment of the present invention. In other words, conventional thin lenses such as “biconvex lens”, “planoconvex lens”, “meniscus convex lens”, “biconcave lens”, “planoconcave lens”, “meniscus concave lens” must use large lenses with an infinite diameter. The function equivalent to the bulk lens 20 according to the first embodiment of the present invention cannot be achieved.

FIG. 5 is a diagram showing the relationship between the geometric structure of the bulk lens 20 and the light collection rate according to the first embodiment of the present invention. Here, the “condensation rate” is the “light quantity of output light at a divergence angle within ± 1 ° from the bulk lens 20” as “light quantity at a divergence angle within ± 15 ° from the light source (LED)”. It is defined by the divided amount. From FIG. 5, when the radius of curvature of the second lens surface (second curved surface) 3 is R and the total length of the bulk lens 20 is L, the above-described equation (1) is used to improve the light collection rate. And it turns out that satisfy | filling (2) Formula is preferable. Here, n is the refractive index of the bulk lens 20. The radius r _e of the cylindrical portion of the bulk lens 20 and the radius of curvature R of the second curved surface are not necessarily equal (generally, r _e ≦ R).

FIG. 6 shows the geometric structure of each bulk lens 20 shown in FIG. 5, that is, the radius of curvature R of each second curved surface, the total length L of the bulk lens 20, the first and second lens surfaces. the distance D between, the inner diameter r _i of the housing part 6 and is a table showing the height Δ of the eggplant protrusion of the first lens surface. Here, “the height Δ of the convex portion formed by the first lens surface” means the convex portion (first portion) formed on a part of the first lens surface (the concave ceiling portion) 2 defined in FIG. Of the curved surface).

  The bulk lens 20 shown in FIG. 1 had a smooth concave first lens surface (2, 5) and a convex second lens surface 3. However, FIG. 1 is an exemplification, and the first lens surface (2, 5) and the second lens surface 3 can employ various shapes depending on the purpose. The height Δ of the convex portion formed by the first lens surface can take either a positive value or a negative value. Alternatively, Δ = 0 may be used. Here, as shown in FIG. 7, a case where a part (concave ceiling portion) 2 of the first lens surface (2, 5) is convex is defined in the positive direction of Δ.

8 (a) to 8 (c), FIGS. 9 (a) to 9 (c), and FIGS. 10 (a) to 10 (c) show the height Δ of the convex portion and the beam intensity shown in FIG. It is a figure which shows the relationship with a profile. The outer diameter 2r _e of the cylindrical portion of the bulk type lens 20 used for the measurement is 15 mm, the total length L of the bulk type lens 20 is 25 mm, a part of the first lens surface (concave portion) 2 and the second lens. the distance D between the surface 3 16 mm, inner diameter 2r _i of the receiving portion 6 5.2 mm, the refractive index n of the bulk-shaped lens 20 is 1.54. The radius of curvature R of the second lens surface 3 of this bulk lens 20 is 8.25 mm. The outer shape of the resin-molded LED 1 used for the measurement is 5 mm. 11 shows the height Δ of the convex portion obtained from the results of FIGS. 8 (a) to 8 (c), FIGS. 9 (a) to 9 (c), and FIGS. 10 (a) to 10 (c). It is a figure which shows the relationship between the flatness of the illumination intensity in the irradiation area in the range of +/- 15cm in the measurement distance 1m. Here, the flatness of the illuminance is
((Maximum value)-(minimum value)) / (average value) (5)
Defined by When the outer diameter 2r _e of the bulk lens 20 is 15 mm,
0.2 mm <Δ <0.6 mm (6)
However, it is preferable to improve the flatness of the illuminance. More generally, the height Δ of the convex portion and the outer diameter 2r _e of the outer peripheral portion may be selected so as to satisfy the above-described expression (3).

Figure 12 is an outer diameter 2r _e bulk lens 20 of the present invention 10 mm [phi, having a diameter of 15 mm, the illuminance distribution in the measured distance x = 0.5 m when changing the 30mmφ shown. It is shown that the relative illuminance increases as the outer diameter 2r _e of the bulk lens 20 increases.

  FIG. 13 shows the measurement of FIG. 12 in more detail, and the results are shown with the thickness between the inner wall portion and the outer wall portion of the bulk lens 20 on the horizontal axis and the relative illuminance (arbitrary scale) on the vertical axis. It is shown. It shows that the relative illuminance increases as the thickness between the inner wall portion and the outer wall portion increases.

  FIG. 14 shows the outer diameter / inner diameter ratio of the bulk lens 20 on the horizontal axis and the relative illuminance (arbitrary scale) on the vertical axis. It shows that the relative illuminance increases as the outer diameter / inner diameter ratio increases. In particular, when the outer diameter / inner diameter ratio is 2.5 or more, a remarkable increase effect is recognized. It can be seen that when the outer diameter / inner diameter ratio is 10 or more, the increasing effect tends to be saturated. Considering the actual outer diameter of the LED, the bulk lens 20 having an outer diameter / inner diameter ratio of 10 or more inevitably increases in diameter. However, the large-diameter bulk lens 20 is likely to have air bubbles or cracks in the lens medium 4, and is difficult to manufacture. Further, it is not desirable from the viewpoint of miniaturization of the apparatus. Therefore, considering FIG. 14, it is understood that an outer diameter / inner diameter ratio of 3 or more and 10 or less is preferable for the bulk lens 20.

FIG. 15 shows a case where a resin-molded LED 1 is housed in the housing portion 6 of the bulk type lens 20 having an outer diameter 2r _e = 15 mmφ, and a rear mirror is attached to the back surface portion and the outer wall portion of the bulk lens 20. It is a figure which compares the intensity | strength (illuminance) distribution along the y direction of each output light when there is no back mirror. In FIG. 15, the measurement is performed at a measurement distance x = 1 m. When the resin-molded LED 1 is stored in the storage unit 6 of the bulk lens 20, it can be seen that the illuminance hardly changes with and without the rear mirror. That is, in the bulk type lens 20, the thickness of the bulk type lens 20 between the inner wall portion and the outer wall portion is selected to be sufficiently thick as shown in the relationship of FIG. Even if a rear mirror is not used for the outer peripheral portion and the bottom portion, stray light components hardly pass through the outer peripheral portion of the lens medium 4 and leak to the outside. And it turns out that the light which injected from these side wall entrance surfaces is radiate | emitted from the output surface of the bulk type lens 20 as an effective illumination component finally. In other words, the bulk type lens 20 eliminates the stray light component of the LED 1 from the second lens surface 3 almost completely (with a condensing efficiency close to 100%) without using a reflecting mirror at the outer periphery or bottom of the lens medium 4. It can be seen that this structure outputs well. That is, FIG. 15 shows that in the bulk type lens 20 according to the first embodiment of the present invention, if the side wall portion is sufficiently thick, the rear mirror at the outer peripheral portion and the bottom portion of the lens medium 4 is meaningless. is there. The “light collection efficiency close to 100%” is because light perpendicularly incident on the recess side wall portion 5 will leak from the outer peripheral portion. However, light incident on the recess side wall 5 at each incident angle determined by the structure of the resin-sealed LED 1 is refracted inside the lens medium 4 at a refraction angle determined by Snell's law. As the thickness of the lens medium 4 located on the side wall of the storage unit 6 increases, the component leaking from the outer periphery of the lens medium 4 decreases as shown in FIG. 13 and FIG. The component that is efficiently output from the lens surface 3 increases. When the geometric shape satisfies the expression (4), the component leaking from the outer peripheral portion of the lens medium 4 can be almost ignored. In particular, in the resin-sealed LED 1, of the light emitted from places other than the convex curved surface, the component that is perpendicularly incident on the concave side wall portion 5 is relative to other stray light components. Therefore, when the geometrical shape satisfies the expression (4), the component leaking from the outer peripheral portion of the lens medium 4 can be almost ignored, and the second lens surface 3 can be efficiently obtained with a light collection efficiency close to 100%. It can be estimated that it will output. For this reason, as shown in FIG. 15, in the case of the resin-molded LED 1, it is considered that the result that the illuminance hardly changes with and without the rear mirror is obtained.

The LED 1 according to the first embodiment of the present invention is molded with a transparent material such as an epoxy resin having a _first refractive index n ₁ . The bulk lens 20 accommodates the LED 1 via air having a second refractive index n ₀ different from the _first refractive index n ₁ . The LED 1 may be stored in the storage unit 6 via a fluid or fluid other than air. Various “fluids” can be used as long as the gas or liquid is transparent to the wavelength of light emitted from the LED 1. Spacer oil or the like can be used between the LED 1 of the storage unit 6 and the bulk lens 20. Further, various sol-like, colloidal or gel-like transparent materials as “fluid” can be used. Further, the bulk lens 20 may have a third refractive index n ₂ different from the second refractive index n ₀ . The first refractive index n ₁ , the second refractive index n ₀ , and the third refractive index n ₂ are selected to be optimum values so that the light from the LED chip 13 is converged or dispersed. Is also possible. The third progressively larger refractive index n ₂ of which has the light transmitting portion of the bulk lens 20, or may be an optical path designed to be gradually reduced.

  Thus, according to the light emitter according to the first embodiment of the present invention, a light beam having a desired irradiation area as a light beam that contributes to illumination without requiring a large number of resin-molded LEDs 1. And 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, it could be realized with only one LED having the same illuminance as a thin flashlight using a halogen lamp currently on the market. As described above, according to the light emitter according to the first embodiment of the present invention, it is possible to realize illuminance which cannot be predicted at all by the conventional technical common sense with a simple structure as shown in FIG.

  In addition, as the resin-molded LED 1 used for the light emitter according to the first embodiment of the present invention, LEDs of various colors (wavelengths) can be used. However, for the purpose of use as a portable lighting device such as a flashlight, white LEDs are preferred because they are natural to the human eye. White LEDs having various structures can be used. For example, three LED chips of red (R), green (G), and blue (B) may be stacked vertically. The three LED chips of red (R), green (G), and blue (B) may be arranged close to each other so that they can be regarded as point light sources on the same plane level. In this case, a total of six pins may be derived from the sealing resin 14 corresponding to the LED chips of the respective colors. As the internal wiring of the sealing resin 14, the six pins are combined into two, Two external pins may be provided. If one electrode (ground electrode) is shared, four external pins are sufficient. In any case, if the driving voltage (driving current) of the three LED chips of red (R), green (G) and blue (B) can be controlled independently of each other, any color can be mixed. Since (color synthesis) is possible, white light can be obtained. Furthermore, it is easy to obtain an arbitrary color other than white light by color synthesis in which the emission intensity of each RGB color is controlled, and it is possible to enjoy a change in hue.

  If a white LED is used as the resin-molded LED 1 shown in FIG. 1 and a battery case and a battery (for example, an AA battery) in the battery case are stored so that a predetermined voltage can be applied to the white LED 1, A pen-type slim flashlight (penlight) is completed. What is necessary is just to set it as the structure which connects the electrode of white LED1 to the anode and cathode of the battery of this lighting fixture, respectively. As a result, a flashlight (portable lighting device) can be provided with a simple structure and a low manufacturing cost. Or lighting fixtures, such as a medical light using the specific color obtained by the color synthesis by control of the light emission intensity of each RGB color, can also be comprised. It is possible to obtain an arbitrary color in the visible light spectrum band by color synthesis in which the emission intensity of each of the RGB colors is controlled. These luminaires are excellent in stability and reliability over a long period of time, and in particular, have excellent characteristics that could not be predicted in the past, such as long battery life due to low power consumption.

  Examples of the bulk lens 20 used in the light emitter according to the first embodiment of the present invention include transparent plastic materials such as acrylic resin, various glass materials such as quartz glass, soda lime glass, borosilicate glass, lead glass, and the like. Can be used. 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 stretchability may be used. Alternatively, sol, gel, sol-gel mixture, etc. may be stored in transparent rubber or flexible transparent plastic material. Among them, a transparent plastic material such as an acrylic resin is a material suitable for mass production of the bulk type lens 20. That is, once a mold is formed and molded by this mold, the bulk lens 20 can be easily mass-produced.

  However, according to simple injection molding, it has been found that abnormal shapes such as bubble entrapment, nest formation, spikes and ice column shapes occur near the ceiling 2 of the well-shaped recess 6 shown in FIG. . According to the detailed examination of the present inventor, the occurrence of such an abnormal shape is caused by the shrinkage of the molten transparent resin during the injection molding, and the vicinity of the ceiling portion 2 of the well-shaped recess 6 is reduced. It was found that this was because the pressure was reduced. For example, since polycarbonate contracts by about 0.4% per 1 ° C., the vicinity of the ceiling portion 2 is in a reduced pressure state. Therefore, in order to manufacture the bulk lens 20 having a good geometric shape, the following may be performed.

  (A) First, a mold for manufacturing the bulk lens 20 is prepared. The molding dies are roughly divided into an upper half fixed mold receiver, a lower half movable mold receiver, and a release mechanism. A fixed mold is fitted inside the fixed mold receiver. This fixed mold has a fixed mold forming surface for molding the outer top 3 and the outer periphery of the bulk lens. At the center of the fixed mold, there is provided a gate for pouring a resin liquid obtained by thermally melting a transparent resin that is a material for forming the bulk lens 20. This gate is connected to a resin liquid supply mechanism, and hot melted transparent resin is intermittently supplied. The movable mold receiver has a movable mold fitted therein. This movable mold is provided with a male mold having a cylindrical storage portion molding surface whose top corresponding to the shape of the storage portion 6 is a curved surface in order to mold the storage portion 6 of the bulk lens 20. The mold release mechanism is provided with a projecting plate that can move up and down inside, and a projecting pin is fixed to an end of the projecting plate and passes through a hole and communicates with the movable mold. The lower part of the protruding plate is connected to a vertical movement mechanism, and pushes the protruding plate upward when the protruding pin is protruded. Then, the movable mold receiver is pressed against the fixed mold receiver and comes into close contact. Then, it is heated to a predetermined mold temperature.

(B) Next, in the first injection step, the molten transparent resin is injected from the gate into the space formed by the fixed mold and the movable mold. As the transparent resin, resins such as polymethyl methacrylate (PMMA), polycarbonate (PC), acrylic, ABS, and AB can be used. For example, pellets thrown in from a hopper are melted by heating and shearing heat generation in a cylinder arranged adjacent to the molding die, and a transparent resin is injected into the gate at high pressure by a hydraulic motor or the like. A screw may be provided in the cylinder, and the material may be melted by rotating the screw. At the time of this resin injection, since the gate is provided in the central part of the fixed mold, the melted transparent resin is filled up to the end of the mold space where the bulk type lens 20 is molded.
(C) After the resin is injected, the first cooling step is performed, and the resin is left for a certain period of time to cool the resin in the molding die. The first cooling step is a step of cooling to an intermediate temperature at which the resin is not completely cooled to room temperature.

  (D) When the resin cools, a gap corresponding to the expansion coefficient of the resin is formed. From the first cooling step, the transparent resin melted again in the second injection step is injected again from the gate into the gap due to the resin being cooled to an intermediate temperature.

  (E) After resin injection in the second injection step, the second cooling step is performed, and the resin is allowed to stand for a predetermined time, and the resin is cooled to room temperature in the molding die.

(F) When the resin is cooled to room temperature, the bulk lens 20 solidified in the molding die is taken out. For example, a solenoid valve connected to a compressor on the stationary mold receiving side is operated to eject compressed air from the annular slit of the stationary mold toward the bulk lens 20 (fixed mold air blow). And a movable metal mold receiver unites with a mold release mechanism part, and falls below. By this compressed air ejection, the bottom part where the storage part 6 of the bulk mold lens 20 is formed is easily released from the fixed mold of the fixed mold receiver, and in close contact with the movable mold side, together with the movable mold receiver Go down.
(G) The movable mold receiver separated from the fixed mold receiver operates the solenoid valve connected to the compressor on the movable mold receiver side, and the compressed air is directed from the annular slit of the movable mold toward the bulk lens 20. (Moveable mold air blow). Thereby, an air layer is formed between the storage part 6 of the bulk mold lens 20 and the storage part molding surface of the movable mold, and the bulk mold lens 20 is released from the movable mold receiver without being damaged. Simultaneously with this movable mold air blow, the projecting plate moves upward, and the projecting pin projects from the hole of the movable mold toward the bulk lens 20. Thus, the bulk type lens 20 is easily released from the movable mold 21, and the bulk type lens 20 is lifted from the columnar male mold of the movable mold so that the bulk type lens 20 is lifted. It is easy to remove from the mold.

  According to the above method, the resin is cooled to an intermediate temperature at which the resin is not completely cooled to room temperature by the first cooling step, and the transparent resin is injected again by the second injection step into the gap formed by the shrinkage of the resin. Therefore, the vicinity of the ceiling portion 2 of the well-shaped recess 6 is prevented from being in a reduced pressure state. As a result, it is possible to prevent air bubbles from being taken in and an abnormal shape from occurring near the ceiling 2 of the well-shaped recess 6 shown in FIG. 1, and a bulk lens 20 having a good geometric shape can be formed.

(Second Embodiment)
As shown in FIG. 16, the light emitter according to the second embodiment of the present invention includes at least a light source 1 that emits light of a predetermined wavelength and a bulk lens 20 that almost completely covers the light source 1. ing. The bulk-type lens 20 includes a bulk-type lens medium 4 having an outer top portion 3, a bottom portion, and an outer peripheral portion composed of side surfaces parallel to the optical axis, and the inside of the lens medium 4 from the bottom portion toward the outer top portion 3. And a storage portion 6 formed of a well-shaped concave portion having a side wall portion formed of a plane parallel to the optical axis. The first lens surface (2, 5) provided in the lens medium 4 as the entrance surface is the ceiling portion 2 and the side wall portion 5 of the storage portion 6, and the outer top portion 3 of the lens medium is the exit surface. Functions as the second lens surface 3. The light source 1 is completely stored in the storage unit 6.

The light source 1 is, for example, an iodine (I ₂ ) tungsten lamp (halogen lamp) having a maximum diameter (outer diameter) of 2 to 3 mm ^φ , that is, a bean lamp-shaped incandescent bulb. The bulk lens 20 has a bullet shape as shown in FIG. Inside diameter 2r _i recess side wall 5 of the housing part 6 of the bulk-shaped lens 20 has a light source to allow housing of the main light-emitting portion of the (incandescent bulb) 1, has a cylindrical shape of ^_2r i = _{2.5~4mm φ} . Although not shown, in order to fix the light source 1 and the bulk lens 20, a thickness of about 1 to 2.5 mm is provided between the socket portion of the light source 1 and the storage portion 6 of the bulk lens 20. (The “socket portion” means a portion on the electrode lead side (left side) of the light source 1 in FIG. 16). The diameter (outer diameter) 2r _e of the cylindrical portion of the bullet type bulk lens 20 can be selected according to the purpose of use of the light emitter according to the second embodiment of the present invention. Accordingly, it may be 10 ^mmφ or less or 30 mm ^φ or more. However, as a matter of course, it is preferable to select the geometric structure of the bulk lens 20 so as to satisfy the expressions (1) to (3) or (6) described above. Further, the bulk lens 20 according to the second embodiment of the present invention has a refractive index n ₁ different from the refractive index n _{0 of} air.

  The light from the incandescent bulb 1 is emitted almost isotropically. In FIG. 16, the concave side wall (side wall incident surface) 5 of the storage unit 6 other than the main incident surface 2 (ceiling) can also function as an effective light incident surface (first lens surface). In the case of the light from the incandescent bulb 1, there are more components incident on the lens medium 4 from the side wall incident surface 5 with respect to the main incident surface 2 than the output light of the LED. Then, between the light source 1 and the storage unit 6 of the bulk lens 20, light components reflected at each interface are multiple-reflected to become stray light components. In a conventionally known optical system such as a lens, these stray light components cannot be extracted so as to contribute to illumination. However, in the second embodiment of the present invention, these stray light components are also confined inside the storage unit 6 and are incident on the lens medium 4 from the side wall incident surface 5, and ultimately contribute to illumination. It can be a component that can be made. As described above, in the second embodiment of the present invention, since the light incident from the side wall incident surface 5 can be effectively collected, it isotropic including the stray light component emitted from the light source 1. All the emitted light can be effectively contributed to illumination.

  Thus, according to the light emitter according to the second embodiment of the present invention, a light beam having a desired irradiation area is secured as a light beam contributing to illumination without requiring a large number of light sources 1. In addition, 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. As described above, according to the light emitter according to the second embodiment of the present invention, the illuminance that cannot be predicted at all by conventional technical common sense can be realized with a simple structure as shown in FIG. As is clear from the comparison between FIG. 2A and FIG. 2B, in order to obtain a light collecting characteristic comparable to that of the present invention, when a conventional thin lens (convex lens) is used, its diameter is Even double the diameter of the cylindrical portion of the bulk lens 20 of the present invention is insufficient, and beam parallelism cannot be obtained even about 3 times. That is, downsizing exceeding 1/3 has been achieved.

  As the bulk lens 20 used in the light emitter according to the second embodiment of the present invention, a heat-resistant optical material is preferable in consideration of heat generation of the light source (incandescent bulb) 1. As the heat resistant optical material, heat resistant glass such as quartz glass and sapphire glass is preferable. Alternatively, a heat-resistant optical material such as a heat-resistant resin such as a polysulfone resin, a polyether sulfone resin, a polycarbonate resin, a polyetheresteramide resin, a methacrylic resin, an amorphous polyolefin resin, or a polymer material having a perfluoroalkyl group It can be used. A crystalline material such as SiC may be used. In addition, when using semiconductor light emitting elements, such as LED, as the light source 1, since it is not accompanied by heat_generation | fever effect | action, it is possible to use resin with weak heat resistance, such as an acrylic resin.

(Third embodiment)
As shown in FIG. 17, the photoreceptor according to the third embodiment of the present invention is a photo diode (photodetector) such as a pin photo diode or an avalanche photo diode that detects light of a predetermined wavelength. 50 and a bulk-type lens 20 that almost completely covers the photodiode. The bulk lens 20 has an incident surface (second lens surface) 3 formed of a second curved surface. From the bottom of the lens medium 4, a storage portion 6 for storing the light receiving portion of the photodetector (photo diode) 50 is formed toward the outer top portion 3. The concave ceiling (concave concave portion) 2 is formed of a first curved surface. Light incident from the incident surface (second lens surface) 3 exits with the concave ceiling portion 2 as the main exit surface. Precisely, the concave ceiling part (main outgoing surface) 2 and the concave side wall part (side wall outgoing surface) 5 constitute a first lens surface serving as an outgoing surface. Then, the light from the first lens surface (2, 5) is condensed on the light receiving portion of the photodetector 50 and enters the photodiode chip 9.

  The photodetector 50 of FIG. 17 includes a photodiode chip 9 disposed on a base integrally connected to the first pin 51 and a second pin 52 that makes a pair with the first pin 51. And at least.

Inside diameter 2r _i recess side wall 5 of the housing part 6 of the bulk-shaped lens 20, such that it houses the light detector 50, and has a cylindrical shape of _2r i = _{2.5~4mm ^φ.} Although not shown, in order to fix the photodetector 50 and the bulk lens 20, a thickness of 0.25 to 0 is provided between the photodetector 50 and the storage portion 6 of the bulk lens 20. A spacer of about 5 mm is inserted. This spacer may be arranged at a position excluding the main light receiving portion of the photodetector 50, that is, to the left of the bottom surface of the photodiode chip 9 in FIG. The bulk-type lens 20 has a cylindrical shape except for the outer top portion 3 having a main incident surface (second lens surface) 3 formed of a convex second curved surface. The diameter (outer diameter) 2r _e cylindrical portion of the bulk-type lens 20 is 10 to 30 mm ^phi. The diameter (outer diameter) 2r _e of the bulk lens 20 can be selected according to the purpose of use of the photoreceptor according to the third embodiment of the present invention. Accordingly, it may be 10 ^mmφ or less or 30 mm ^φ or more.

(Fourth embodiment)
Furthermore, an optical information communication system can be configured by the light emitter shown in FIG. 1 and the light receiver according to the third embodiment of the present invention.

[Luminous body]
As shown in FIG. 18A, the light emitter according to the fourth embodiment of the present invention has a bulk lens 24 and a predetermined wavelength housed in the first housing portion 6t of the bulk lens 24. And a light source 1 that emits light. The bulk-type lens 24 includes a first lens medium 4t having a first outer top portion 3t, a first bottom portion, and an outer peripheral portion formed of side surfaces parallel to the first optical axis, and the first lens medium 4t. It is comprised from the 1st accommodating part 6t provided in the inside. The first storage portion 6t is formed of a well-shaped recess formed from the first bottom portion of the first lens medium 4t toward the first outer top portion 3. The well-shaped recess has a side wall portion formed of a plane parallel to the optical axis.

  The light source 1 is configured to be relatively movable in the direction of the outer apex 3 or the rear surface direction inside the first storage portion 6t of the bulk lens 24 by the light source position control / driving means. As a part of the light source position control / driving means, a back support 30t disposed on the rear surface of the bulk lens is disposed. The back support 30 t is formed to extend to a part of the side surface of the bulk lens 24. Further, in order to relatively move the light source 1 and the bulk type lens 24 including the back support 30t, a protrusion 40 is formed on the bulk type lens. The protrusion 40 also functions as a part of the light source position control / drive means.

  In FIG. 18A, the back support 30 t is formed of a main support 31 t disposed directly on the rear surface of the bulk lens 24 and a small back mirror 32 t disposed in the middle of the LED holder 45. The small rear mirror 32t may be disposed immediately after the light source 1. Further, the small rear mirror 32t may be disposed twice in the middle of the LED holder 45 and immediately after the light source 1, and may be omitted at all in consideration of the result shown in FIG. In FIG. 18A, the back support 30 t covers a part of the side surface of the bulk type lens 24, but it may be formed so as to cover almost the entire side surface of the bulk type lens 24. In this case, the protrusion 40 is formed on the rear mirror. The back support 30t may be configured by grinding a metal such as aluminum, brass, or stainless steel using a lathe / milling machine or the like by a press machine, and then polishing the surface. Furthermore, since the reflectance is improved by applying nickel (Ni) plating or gold (Au) plating to these surfaces, it is possible to function as a reflecting mirror. As an inexpensive and simple method, a structure in which a metal thin film having a high reflectance such as an Al thin film is bonded may be used. Alternatively, a thermoplastic resin is processed into the shape shown in FIG. 18A by extrusion molding or injection molding, and a metal thin film or a dielectric multilayer film having a high reflectance such as an Al foil is deposited on this surface by vacuum evaporation or sputtering. A structure or a structure in which a highly reflective polyester white film or the like is adhered may be used. Further, a structure in which a metal thin film or a dielectric multilayer film having a high reflectance is directly deposited on the rear surface of the bulk type lens 14 by vacuum deposition or sputtering, a structure in which a metal thin film having a high reflectance is formed by plating, or a composite film thereof can be used. I do not care.

  The light source 1 in FIG. 18A is fitted in the hollow portion of the LED holder 45 connected to the first pin 11, and the LED chip 13 whose end portion is fixed, and the sealing that covers the LED chip 13. The resin-molded LED includes at least a resin 14t and a second pin 12 paired with the first pin 11. The small rear mirror 31 has a hole through which the first pin 11 and the second pin 12 penetrate, and the first pin 11 and the second pin 12 are not electrically short-circuited to the small rear mirror 31. Is taken into account. The light from the LED chip 13 has a double-sided light emitting structure in which the light is extracted also from the back surface direction of the LED chip 13 (right direction in FIG. 18A). The support ring does not need to be a completely closed ring, and may be a non-closed ring such as a C-shape or a U-shape. In short, any structure that can fix a part of the end face of the light source 1 may be used.

  The protrusions 40 provided on the bulk type lens 24 are arranged in a ring shape in the circumferential direction of the side surface of the bulk type lens 24, and correspond to the depression of the lens holder that covers the side surface of the bulk type lens 24, although not shown. Is formed. A plurality of the ring-shaped protrusions 40 may be arranged in the optical axis direction (horizontal direction in FIG. 18A). Further, the protrusion 40 may be formed of a plurality of small protrusions arranged radially in the circumferential direction instead of a continuous ring shape. Alternatively, a plurality of depressions or the like may be formed on the outer surface of the bulk lens 24 or the back support 30t. As a simple method, a thread made of a spiral protrusion may be formed on the outer surface of the bulk lens 24 to form a male screw. Alternatively, a spiral groove may be formed to form a male screw thread. Since the outer periphery of the lens medium 4 does not need to be a reflecting mirror, the outer periphery of the lens medium 4 can be freely deformed into a desired shape. The light source position control / driving means may be configured by forming a female screw thread in the storage portion 6t of the bulk lens 24 and forming a male screw thread in the LED holder 45. As an extreme example, as long as it is firmly held and focus adjustment is possible, nothing needs to be formed.

  Except for the hemispherical head, the light source 1 has a cylindrical shape having a diameter (outer diameter) of 3 to 5 mm, for example. The side wall portion of the storage portion 6t of the bulk lens 24 has a cylindrical shape with a diameter (inner diameter) of 4 to 6 mm so that the light source 1 can be stored. As shown in FIG. 18A, the light source 1 is fixed to an LED holder 45 whose head is cup-shaped, and the light source 1 is held via the LED holder 45. The LED holder 45 may be made of an electrically transparent material having high electrical insulation.

  The bulk lens 24 has a cylindrical shape that is substantially similar to the light source 1. The diameter (outer diameter) of the cylindrical portion of the bulk lens 24 is 10 to 30 mm. The diameter (outer diameter) of the bulk lens 24 can be selected according to the purpose of use of the light emitter according to the fourth embodiment of the present invention. Therefore, it may be 10 mm or less or 30 mm or more.

  The cross section of the protrusion 40 is, for example, a semi-elliptical shape having a width of 1 to 2 mm and a height of 1.5 to 3 mm. The length in the circumferential direction is not limited, but 3 mm or more is preferable. As the material, the same material as that of the bulk type lens 24 and the back support 30t may be used and may be formed at the same time. Moreover, you may stick the thing formed with the completely different material with the adhesive agent. Any shape, material, arrangement, and formation method may be adopted as long as the force transmitted from the lens holder can be transmitted to the bulk lens 24.

  In a general resin-molded LED, light emitted from places other than the convex curved surface of the sealing resin 14t becomes a so-called stray light component and does not contribute to illumination. However, in the fourth embodiment of the present invention, the light source 1 is almost completely confined in the storage portion 6t of the bulk lens 24 and can enter from the side wall incident surface of the storage portion 6t. Most of the power can be output from the outer top 3 which finally becomes the exit surface. As a result, it is possible to effectively extract the light energy of the potential LED chip 13 without depending on the light extraction efficiency such as the shape of the sealing resin 14t and the reflection components between the optical systems. Furthermore, since the light source 1 is relatively moved via the light source position control / driving means using the projection 40 and the focus can be adjusted, a directional parallel light beam or a light beam having an arbitrary divergence angle is obtained. I can do it. That is, the light emitted from the light source 1 can be used to the limit.

  In FIG. 18A, the outer apex 3 of the bulk lens 24 has an exit surface that is a hemispherical curved surface. However, FIG. 18A is an example, and various shapes can be adopted as the curved surface according to the purpose, and a bulk type lens having an exit surface composed of a concave curved surface may be used.

[Photoreceptor]
On the other hand, as shown in FIG. 18B, the photoreceptor according to the fourth embodiment of the present invention has a bulk lens 25 and a predetermined housing housed in the second housing portion 6r of the bulk lens 25. And a photodetector 50 for detecting light having a wavelength of. The bulk-type lens 25 includes a second lens medium 4r having a second outer top portion 3r, a second bottom portion, and an outer peripheral portion formed of a side surface parallel to the second optical axis, and a second lens medium 4r and a second bottom portion. A second storage portion 6r formed of a well-shaped concave portion having a side wall portion formed of a surface parallel to the optical axis is provided inside the second lens medium 4r toward the outer top portion 3. The concave ceiling part 2r of the second storage part 6r functions as the main exit surface 2, and the second outer top part 3r functions as the incident surface.

  The photoreceptor according to the fourth embodiment of the present invention further includes photodetector position control / drive means for relatively moving the photodetector 50 in the direction of the outer apex 3r or the rear surface. The photodetector position control / driving means uses a back support 30r disposed on the rear surface of the bulk lens 25 as a part thereof. The back support 30r is formed to extend to almost the entire side surface of the bulk lens 25. The photodetector position control / driving means uses the protrusion 41 formed on the back support 30r as a part thereof in order to relatively move the photodetector 50 and the bulk lens 25 including the back support 30r. ing. In FIG. 18B, the back support 30 r is formed of a main support 31 r disposed directly on the rear surface of the bulk lens 25 and a small back mirror 32 r disposed immediately after the photodetector 50. . The small rear mirror 32 r may be arranged in the middle of the light receiving element holder 55. In addition, the small rear mirror 32r may be disposed in the middle of the light receiving element holder 55 and immediately after the photodetector 50, or may be omitted at all. In FIG. 18B, the back support 30r covers almost the entire side surface of the bulk lens 25, but may be formed so as to cover only a part of the side surface of the bulk lens 25. . In this case, the protrusion is formed on the bulk type lens 25.

  The photodetector 50 in FIG. 18B includes a photodiode chip 9 that is fitted in the hollow portion of the light receiving element holder 55 connected to the first pin 51, and has its end fixed, and the photo diode 50. It comprises at least a sealing resin 14r that covers the diode chip 9 and a second pin 52 that forms a pair with the first pin 51. The diameter (outer diameter) of the hemispherical head and the cylindrical body of the photodetector 50 is, for example, 3 to 5 mm.

  Here, regarding the light receiving body according to the fourth embodiment of the present invention, the light source 1 of the light emitting body in FIG. 18A is simply replaced with the photodetector 50, and the light source 1 and the photodetector are replaced. Since the 50 shapes are also substantially the same, redundant description will be omitted.

  In conclusion, in the fourth embodiment of the present invention, the photodetector 50 is almost completely enclosed in the storage portion 6r of the bulk lens 25, and the back support 30r is disposed on the rear surface of the bulk lens 25. In addition, since the position of the photodetector 50 can be adjusted via the photodetector position control / driving means using the protrusion 41, the light incident from the outer top 3 serving as the light receiving surface is limited to the limit. Can be used.

  With the photoreceptor according to the fourth embodiment of the present invention, it is possible to realize a sensitivity that cannot be predicted by conventional common sense with a simple structure as shown in FIG.

[Optical information communication system]
In the optical information communication system according to the fourth embodiment of the present invention, if a semiconductor light emitting element such as an LED that has little heat generation action during light emission is used, the inside of the concave portion (housing portion) 6t of the bulk lens 20 will be described. In addition, even when the light source 1 is housed, it is preferable because the heat generation action does not affect the bulk lens 20 thermally, and reliability and stability can be maintained even in long-term operation. Further, as already described in the first embodiment of the present invention, an optical signal can be output with high efficiency. On the other hand, the light receiver reaches the photodetector in the reverse process of the light emitter, and light detection with extremely high sensitivity is possible. The optical information communication system according to the fourth embodiment of the present invention uses optical information as encryption in addition to simple optical communication to open / close a door, open / close a safe door, open / close a desk drawer, etc. It may be used for security systems.

(Fifth embodiment)
As shown in FIG. 19 (a), the light emitter according to the fifth embodiment of the present invention includes a flexible bulk lens 20f having flexibility or flexibility, and a storage portion 6f of the flexible bulk lens 20f. The light source 1 is housed. The flexible bulk lens 20f includes an outer apex 3f serving as an output surface, a rear surface facing the outer apex 3f, an optical transmission unit connecting the outer apex 3f and the rear surface, and a part of the rear surface along the outer apex 3f direction. And at least a storage section 6f formed inside the optical transmission section. A part or the whole of the flexible bulk lens 20f is made of a material (flexible lens medium) 4f that has flexibility or flexibility and can be easily deformed.

  The light source 1 in FIG. 19A includes a first pin 11, an LED chip 13 arranged with its end fixed, a sealing resin 14 covering the LED chip 13, and a first pin 11. The resin-molded LED is composed of at least a second pin 12 paired with the LED. The light source 1 has a hemispherical head and a cylindrical body, and the diameter (outer diameter) of the body is, for example, 3 to 5 mm. The flexible bulk lens 20f shown in FIG. 19A has a shape substantially similar to that of the light source 1. The diameter (outer diameter) of the cylindrical portion of the flexible bulk lens 20f is, for example, 10 to 30 mm, but may be 10 mm or less or 30 mm or more. The shape of the storage portion 6f formed inside the flexible bulk lens 20f is a cylindrical shape having a diameter (inner diameter) of 3.5 to 5.5 mm so that the light source 1 can be stored.

  The light source 1 is fixed to an accommodating portion 6f formed inside the flexible bulk lens 20f with an adhesive or the like. However, the diameter (inner diameter) of the storage portion 6f formed inside the flexible bulk lens 20f is set to be slightly smaller than the diameter (outer diameter) of the light source 1 and is fixed using the elasticity of the storage portion 6f. good. Moreover, you may fix using both the adhesive agent etc. and the elasticity of the accommodating part 6f.

  As the material of the flexible bulk lens 20f, a substance that is highly transparent with respect to the emission wavelength of the light source 1 and that exhibits appropriate elasticity, such as a silicone polymer, a fluoropolymer, and a transparent acrylic polymer, can be used. Recently, a transparent thermoplastic elastomer (TPE) that can be molded when the temperature is raised has been produced, and this may be used. Moreover, although natural transparency is inferior, natural rubber or the like may be used.

  Furthermore, as shown in FIG. 20, the flexible bulk lens 20f may be configured by a combination of an inelastic lens medium 4d and a flexible lens medium 4f. When configured in combination with the non-inelastic lens medium 4d, a substance that is transparent with respect to the emission wavelength of the light source 1, such as a transparent glass material or a transparent plastic material, can be used as the inelastic material. Alternatively, a crystalline material such as a semiconductor single crystal, a polycrystal, or an amorphous material may be used as the inelastic material. Further, a flexible lens medium 4f made of a plurality of transparent elastic materials and an inelastic lens medium 4d may be combined. That is, if the flexible lens medium 4f made of a transparent elastic material is used at least in part, a combination with other transparent materials including the non-elastic lens medium 4d can be adopted depending on the purpose. As shown in FIG. 20, various shapes can be realized by combining the inelastic lens medium 4 d and the flexible lens medium 4 f. Thereby, it is possible to protect the light source 1 such as an LED, the installed device, or both.

  In the light emitter according to the third foundation of the present invention, at least a part of the bulk type lens 25 (the hemispherical lens portion) including the outer top portion 3f serving as the emission surface is formed of “an easily deformable material”. Therefore, the focal length can be adjusted within a considerable range. For example, as shown in FIG. 19B, when the illuminant is mounted so as to be pressed against a transparent plate 81 such as a flat glass surface, the radius of curvature of the lens tip becomes large, and the light is less than that before mounting. Diverge. As shown in FIG. 19C, when the light emitter is mounted so as to be pressed against a hole 83 or the like narrower than the outer diameter of the flexible bulk lens 20f provided on the light shielding plate 82, the flexible bulk lens 20f The radius of curvature of the tip is reduced, and the light converges compared to before mounting. As described above, according to the light emitter according to the third basis of the present invention, the commercially available light source 1 can be used as it is, the focus can be adjusted, and the versatility for which the purpose and purpose are not selected. Can be provided.

  Further, as shown in FIG. 21, a shape having the effect of an optical fiber is also possible. By applying the forces F1 and F2, it is possible to bend into a desired shape. Depending on the refractive index of the flexible lens medium 4f and the curvature of the flexible lens medium 4f corresponding to the installation state, the flexible lens medium 4f can be used for backlight illumination, indirect illumination, and for interiors such as bedrooms. Like a graded index fiber, if the refractive index is distributed so that the refractive index along the center line is maximized and the refractive index decreases parabolically as it approaches the surface, light leaks when bent. Can be suppressed.

(Sixth embodiment)
As shown in the block diagram of FIG. 22, the distance measuring system according to the sixth embodiment of the present invention includes a light emitting unit and a light receiving unit. This distance measurement system is suitable for simple water level gauges, snow level gauges, and the like. The light emitting unit includes at least a light emitter 61, a drive unit 62 that modulates the output of the light emitter 61 and emits light, a light emitter 61, and a first power supply unit 63 that supplies a power supply voltage to the drive unit 62. The light receiving unit includes a light receiving body 71, a detection section 72 that detects and amplifies the signal of the light receiving body 71, a calculation section 73 that calculates a distance from the light receiving position, an output section 74 that outputs a calculation result, and a detection section 72 and a calculation section. 73 and a second power supply unit 75 that supplies a power supply voltage to the output unit 74.

  FIG. 23 shows a simplified distance measuring method according to the sixth embodiment of the present invention.

  (A) First, a straight line passing through the light emitting point A and the light receiving point B is set as a reference line X, and the distance L is accurately measured. A light emitter 61 is installed at the light emitting point A, and a light receiver 71 is installed at the light receiving point B. Further, a gauge point P whose distance is to be measured is arranged on the same plane where the light emitting point A and the light receiving point B exist.

  (B) Next, the output direction of the light emitter 61 installed at the light emitting point A on the reference line X is determined in the direction of the reference point P. That is, the output direction of the light emitter 61 is directed from the reference line X toward the irradiation angle α. Even if an LED is used as the light source, the output light from the light emitter 61 becomes a parallel light beam close to laser light. Then, the parallel rays are applied to the surface of the object at the mark P. The parallel rays that have reached the surface of the object at the reference point P are reflected and scattered by the surface of the object at the reference point P.

  (C) The reflected light (or scattered light) on the surface of the object at the reference point P is detected by the light receiving body 71 installed at the light receiving point B. And the detection angle (beta) from the reference line X from which the detection output of the reflected light (or scattered light) on the surface of the object of the target point P which the light receiver 71 detected becomes the maximum is measured.

  (D) Since the angles of one side and both ends of the triangle have been determined, the distance H from the reference line X to the gauge point P is obtained.

  The light emitter 61 in FIG. 22 is a light emitter using the bulk type lens 24 shown in FIG. A screw thread made of a spiral projection is formed on the outer surface of the bulk type lens 24 shown in FIG. 18 (a) to form a male screw, and a female screw is formed on the outer lens holder to constitute a light source position control / drive means. Keep it. By rotating the lens holder outside the bulk type lens 24 with this light source position control / driving means, the light source 1 and the bulk type lens 25 move relatively, and the focal length can be varied. In the case of distance measurement, the focal length is generally set to infinity. For example, as one method, the light emitter 61 is turned on toward a substantially vertical surface at a distance of 2 to 3 m, and the light projecting surface may be adjusted to a minimum. Moreover, the structure which can lock the position is preferable. As the light source 1, a wavelength band having a weak spectrum intensity of sunlight is selected in order to avoid the influence of sunlight or the like. For this reason, it is preferable to use short wavelength LEDs such as blue and purple, ultraviolet LEDs, or infrared LEDs rather than general visible light LEDs. Since the ultraviolet LED or the infrared LED cannot visually confirm the irradiation of the parallel light beam on the surface of the object P, it is preferable to superimpose the light of the visible light LED such as blue and purple. Further, when it is desired to increase the output because the reflectance of the gauge point is low, a plurality of LEDs may be arranged in the storage unit 6 in the bulk type lens 24. Of course, the irradiation angle α can be accurately measured from the reference line X.

  The drive unit 62 in FIG. 22 modulates the light emission time (pulse width) and light emission interval (repetition frequency) of the output light of the LED in order to avoid the influence of sunlight or the like. Therefore, the drive unit 62 includes a modulator that performs pulse width modulation on the power supply voltage supplied from the first power supply unit 63. The drive unit 62 is equipped with a programmable one-chip microcomputer or an equivalent product, and its output is used as an input signal to the modulator. If necessary, a parallel input / output LSI, an amplifier, or the like may be added to supplement the function. As a simple method, a notebook personal computer or the like may be used, and the drive unit 62 may be directly controlled via a printer parallel interface attached thereto.

  The first power supply unit 63 and the second power supply unit 75 shown in FIG. 22 have a structure in which a commercially available dry battery, a rechargeable nickel-cadmium (Ni-Cd) battery, or the like can be used to reduce the size and weight of the device and reduce the cost. preferable. Moreover, the structure which supplies an alternating current power supply from the outside, transforms and rectifies and uses this may be sufficient.

  The photoreceptor 71 in FIG. 22 is a linear sensor in which a photoreceptor using the bulk lens 25 shown in FIG. 18B is used as a pixel and a plurality of pixels are used. In other words, a one-dimensional photodiode array is formed in which light receivers (pixels) including the bulk type lens 25 shown in FIG. 18B are arranged on a straight line at a constant interval. Each pixel has a variable focal length structure in which the photodetector 50 and the bulk lens 25 can be relatively moved by the photodetector position control / driving means. In the case of distance measurement, the focal length is generally set to infinity, but in this case, it is preferable to adjust each position in advance and lock the position. As a matter of course, each pixel selects a photodetector 50 having a peak wavelength corresponding to the emission wavelength of the light source 1. The photodetector 50 may be a photodiode chip 9 made of a semiconductor material having the same optical intrinsic energy as the LED chip 13 of the light source 1. Here, the “optical intrinsic energy” means the energy intrinsic to each semiconductor material as a semiconductor material that determines the main emission wavelength of the LED chip 13. As is well known, the forbidden bandwidth (energy gap) of the semiconductor material is the most representative factor for determining the main emission wavelength of the LED chip 13. Therefore, when the emission wavelength of the LED chip 13 is determined by the forbidden band width, the photodetector 50 may use the photodiode chip 9 made of a semiconductor material having the same forbidden band width as the LED chip 13. . That is, by making the optical intrinsic energy (forbidden band width) of the LED chip 13 equal to the optical intrinsic energy (forbidden band width) of the photodiode chip 9, the resonance effect can be used, and the most sensitive light detection is possible. It becomes. If the impurity level is involved in the emission wavelength, it is necessary to consider the impurity added (doped) to the semiconductor material. In this case, it is possible to reversely bias and use the same LED chip as the LED chip 13 as the photodetector 50, and an avalanche made of a semiconductor material having the same optical intrinsic energy (forbidden bandwidth). A photodiode (APD) may be used. Furthermore, detection may be performed while amplifying the light output by using a phototransistor configured using a semiconductor material having exactly the same optical intrinsic energy (forbidden band width) as the LED chip 13. In the distance measuring system according to the sixth embodiment of the present invention, the same LED chip as the LED chip 13 is reverse-biased and used as the photodetector 50 used for each pixel. Thus, when forward-biased, it functions as an LED and each pixel becomes a light emitter.

  It is very difficult and unrealistic to set the surface of the object so that the reflected light from the general object arranged at the reference point P always reaches the light receiving point B. A very weak scattered light reaches the light receiving point B from a general object arranged at the reference point P. Since scattered light is weaker than sunlight, it is impossible to detect the scattered light as a significant signal in the daytime. In order to detect the scattered light as a significant signal in the daytime, a reflector of a certain angle is arranged on the surface of a general object arranged at the target point P so that the reflected light always reaches the light receiving point B. Set in advance. In the case of an object having a good reflectivity at a certain angle (horizontal plane) such as a water surface or a snow surface, the reflector can be omitted, but in this case also, a reflector having a reflectivity of 90% to 95% It is preferable to set it above. Therefore, the detection angle β is adjusted so that each pixel of the one-dimensional photodiode array (linear sensor) 71 faces the direction of the reference point P. In the case of a water level meter or the like, if the irradiation angle α and the detection angle β are set equal, the reflecting mirror may be parallel to the horizontal plane, so that setting is easy.

At this time, the LED chip 13 of the pixel at the center of the one-dimensional photodiode array 71 is forward-biased so as to function as an LED, and visible light is applied to the reflecting mirror on the surface of the object at the point P, and the detection angle is visually observed. Adjust β. This is because, as described above, the same LED chip as the LED chip 13 is used as the photodetector 50 used for each pixel, so that it functions as both the photodetector 50 and the LED. What is necessary is just to set the other pixel which comprises the one-dimensional photodiode array 71 so that it may become the same angle as this center pixel. Of course, the one-dimensional photodiode array 71 may be moved sequentially in the direction of the reference line X using a step motor or the like, and all pixels may function as LEDs to adjust the detection angle β. In this way, if the detection angle β is adjusted so that each pixel of the one-dimensional photodiode array 71 faces the direction of the reference point P, if the object moves by a distance ΔH, a reference is made by ΔL proportional to the distance. Since the light receiving point B moves along the line X, the moving distance ΔL is measured by the one-dimensional photodiode array 71. As can be easily seen from FIG.
ΔL = ΔH (cotα + cotβ) (7)
Given in. In this state, the measurable distance is determined by the length of the array of the one-dimensional photodiode array 71. Therefore, the irradiation of the light emitter 61 is performed so that the reflected light reaches the range of the array length of the one-dimensional photodiode array 71. The angle α is feedback controlled using a step motor or the like. At the same time, in accordance with the control of the irradiation angle α, the detection angle β is also feedback controlled using a step motor or the like.

  Specifically, in the one-dimensional photodiode array 71, 16 to 32 pixels are arranged in a straight line on the pixel holder at a pitch of 50 to 100 mm. Each pixel rotates in conjunction with each other so that the detection angle β can be adjusted. Further, the number and pitch of the pixels arranged in the one-dimensional photodiode array 71 may be set in any way as long as they are physically possible.

  The detection unit 72 in FIG. 22 controls the gate in synchronization with the light emission interval (repetition frequency) of the LED emitting modulated light, and performs synchronous detection on the outputs from all the pixels on the one-dimensional photodiode array 71. I do. Furthermore, the synchronously detected output may be integrated at a constant time interval. At the same time, the detection unit 72 detects the irradiation angle α and the detection angle β every moment. The detected pixel output of the one-dimensional photodiode array 71, the irradiation angle α, and the detection angle β are sequentially transmitted to the calculation unit 73. If necessary, a parallel input / output LSI, an amplifier, an A / D converter, an adder, a timer module, and the like can be added to the detection unit 72 to supplement its function.

  As the calculation unit 73 in FIG. 22, a device having a calculation capability such as a notebook personal computer can be used. What is necessary is just to use it via peripheral devices, such as an I / O parallel interface card, as needed. In order to obtain a highly accurate calculation result from a limited number of data, for example, it is necessary to interpolate between pixels at intervals of 10 mm and obtain an approximate value thereof. Various interpolation formulas and approximation formulas are known, including Lagrange's interpolation formula. The important thing is the selection of the generating function that is the basis of the formula. Since the light emitted from the illuminant 61 is scattered to some extent by dust, dirt, etc. floating in the air while being reflected by the mark and reaching the pixel, the intensity of the received light is expected to follow a normal distribution. . Therefore, by checking in advance the average value μ and dispersion σ of the illuminant 61 to be used, it is possible to interpolate an arbitrary position between pixels very accurately and obtain an approximate value thereof. As a simple interpolation method, a three-point interpolation method using a spline function, a Bezier curve, or the like may be employed. When obtaining the distance with further accuracy, the number of pixels on the one-dimensional photodiode array 71 may be increased, the interpolation interval may be further reduced, or both of them may be employed. In order to maintain measurement accuracy, it is desirable to perform periodic calibration of both units.

  As the output unit 74 of FIG. 22, a liquid crystal screen such as a notebook personal computer is preferable because it consumes less power, but a printer or a CRT display can be selected as necessary. Further, when sending real-time data to a remote place, it may be output to a communication line via a modem or the like.

  As described above, according to the distance measuring system according to the sixth embodiment of the present invention, it is possible to provide a distance measuring system that is compact, highly reliable, highly accurate, and has low power consumption.

(Other embodiments)
As described above, the present invention has been described according to the first to sixth embodiments. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

For example, as shown in FIG. 24, the outer top portion 3c serving as the exit surface of the bulk lens 28 of the present invention may have a concave shape with respect to the exit direction. By adopting the structure of the outer apex 3c shown in FIG. 24, the light output from the outer apex 3c diffuses with a wide divergence angle. The light emitter according to another embodiment of the present invention shown in FIG. 24 is composed at least of a resin-molded LED as the light source 1 and a bulk lens 28 that almost completely covers the light source 1. The bulk type lens 28 is a bulk type (bullet type) lens medium 4 having an outer top part (outgoing surface) 3c that is concave with respect to the outgoing direction, a bottom part, and an outer peripheral part that is a side surface parallel to the optical axis. And a receiving portion 6 made of a well-shaped recess having a side wall portion formed in a plane parallel to the optical axis, which is provided inside the lens medium 4 from the bottom portion toward the outer top portion 3c. The ceiling part (concave part ceiling part) of the recessed part which comprises the accommodating part 6 provided in the inside of the lens medium 4 is the main incident surface (main incident surface of the first lens surface) 2, and the top part (outer top part) of the lens medium 4. Functions as the exit surface (second lens surface) 3c, as in the first embodiment. The first lens surface (2, 5) is composed of a main incident surface 2 formed of a first curved surface and a side wall incident surface 5 having a curvature different from that of the first curved surface. Light incident from the main incident surface 2 is output from the second lens surface 3c, that is, the second curved surface 3c that is concave in the emission direction. Except for the curved surface portion of the convex shape, LED1 is, for example, a cylindrical shape with a diameter (outer _diameter) 2r LED = _{2~3mm ^φ.} Side wall portion of the housing part 6 of the bulk-shaped lens 28, as can be accommodated a primary emission portion of the LED1 that is resin molded, and has a cylindrical shape with a diameter (inner diameter) _2r i = 2.5~4mm ^φ. The bulk lens 28 has a cylindrical shape that is substantially the same as that of the LED 1 except for the outer top portion 3c having an exit surface that is a concave second curved surface. The cylindrical portion of the bulk-shaped lens 28 having a diameter (outer diameter) 2r _e is 10 to 30 mm ^phi. The diameter (outer diameter) 2r _e of the bulk lens 28 can be selected according to the purpose of use of the light emitter.

Even when the emitted light is diffused, it is preferable to satisfy the relationship of the expression (4) described in the first embodiment in order to increase the light collection efficiency of the light of the LED 1. The diameter of the bulk-shaped lens 28 (outside diameter) 2r _e is at least 10 times the internal diameter 2r _i of the receiving portion 6, the bulk lens of the present invention, will function, becomes larger than necessary, and the purpose of downsizing This is not preferable. In the bulk type lens 28 having a geometrical shape satisfying the expression (4), stray light components emitted from places other than the convex curved surface of the LED 1 are effectively illuminated with a light collection efficiency close to 100%. You can contribute. That is, also in the structure of FIG. 24, the side wall portion (recessed side wall portion) 5 of the storage unit 6 other than the main incident surface (recessed ceiling portion) 2 formed of the first curved surface is also effective light incident surface (sidewall incident). Surface). By designing the geometric structure with a sufficiently thick side wall so as to satisfy the formula (4), the light input from the concave side wall 5 is bulky without using a reflecting mirror on the outer periphery. Output (leakage) can be prevented from being directly output from the outer peripheral portion of the mold lens 28. Of course, the light incident perpendicularly to the recess side wall portion 5 leaks from the outer peripheral portion. However, light incident on the concave sidewall 5 at a certain incident angle is refracted at a refraction angle determined by Snell's law. As the thickness of the lens medium 4 located on the side wall portion of the storage portion 6 increases, the component leaking from the outer periphery of the lens medium 4 decreases. And if it becomes the geometrical shape which satisfies (4) Formula, it will be considered that the component which leaks from the outer peripheral part of the lens medium 4 becomes almost negligible. In particular, in a resin-sealed LED, there is little component perpendicularly incident on the concave portion side wall portion 5 in the light emitted from places other than the convex curved surface, so that the geometric shape satisfying the equation (4) is obtained. Then, the component leaking from the outer periphery of the lens medium 4 can be almost ignored.

  The shape of the cross section perpendicular to the optical axis direction of the bulk lens of the present invention can be a perfect circle, an ellipse, a triangle, a quadrangle, a polygon, or the like. Therefore, the outer peripheral portion formed of the side surface parallel to the optical axis of the bulk type lens medium may be a cylinder or a prism. As shown in FIG. 25, the first curved surface 2c serving as the main incident surface of the first lens surface may be conical. Various values such as 90 ° to 120 ° can be adopted for the apex angle of the cone. The other structure of the bulk type lens 27 shown in FIG. 25 is the same as that of the first embodiment, and is a bulk type having an outer top part (outgoing surface) 3, a bottom part, and an outer peripheral part composed of side surfaces parallel to the optical axis ( A cannonball type lens medium 4, and a housing part 6 formed of a well-shaped concave part having a side wall part formed in a plane parallel to the optical axis provided in the lens medium 4 from the bottom part toward the outer top part 3. have. The concave ceiling part (recessed ceiling part) constituting the storage part 6 provided inside the lens medium 4 is a conical main incident surface (main incident surface of the first lens surface) 2c, and the top of the lens medium 4 ( The outer top part) functions as an emission surface (second lens surface) 3. The first lens surface 2c includes a conical main incident surface 2c as a first curved surface and a side wall incident surface 5 having a different curvature from that of the conical shape. The storage portion 6 includes a conical recess ceiling portion 2c and a recess side wall portion (side wall incident surface) 5 formed continuously with the conical recess ceiling portion 2c to form a recess. Light incident from the conical main entrance surface 2 is output from the second lens surface 3. Of course, it is important for the structure of FIG. 25 to satisfy the formula (4) described in the first embodiment in order to effectively extract the light energy of the potential LED chip 13.

  Further, the exit surface 3 of the bulk type lens 20, 22, 24, 25, 27 of the present invention may be a Fresnel lens having a concentric curved surface. Alternatively, it may be a surface having a plurality of curvatures or a fish-eye lens structure.

In the description of the first embodiment, a case has been described in which a spacer is inserted between the light source 1 and the storage unit 6 of the bulk lens 20 to fix the light source 1 to the bulk lens 20. Of course, it may be fixed using other means such as an adhesive, a screw or a clamp mechanism. Further, the outer diameter 2r _LED light source 1 and the inside diameter 2r _i of the housing part 6 by substantially the same, may be fitted.

  Furthermore, the outer shape of the bulk lenses 20, 22, 24, 25, 27, and 28 does not necessarily have to be optically flat, and may have fine irregularities such as crystal glass. If fine irregularities are provided, the output light diverges in all directions, which is convenient in the case of backlight illumination or indirect illumination.

  In the first embodiment, the lighting fixture has been described. Since sufficient brightness as a lighting fixture can be obtained, it can also be applied as a display device. In particular, the display device that displays the color depending on the color of the subway route guide or the like is preferable because sufficient brightness can be obtained for each color. As described in the first embodiment, if the current applied to the red LED chip, the yellow LED chip, and the blue LED chip is controlled independently, any color can be synthesized, and this can be combined with various display devices. Can be used. In particular, by color synthesis, it is possible to finely adjust the emission wavelength to a color that can be easily seen by persons with color blindness. Color vision abnormalities are classified into three types: one color type color vision (all color blindness), two color type color vision (color blindness), and abnormal three color type color vision (color weakness). Two-color type color vision is classified into first color blindness, second color blindness, and third color blindness. In reality, it is difficult to combine colors that satisfy all color blind people. However, even in this case, we conducted experiments including various environments in the field, selected the best color that would satisfy as many color blind persons as possible, and realized a display device that is friendly to color blind persons I can do it. In addition, it can be employed as a display device used for various road signs, traffic signs, destination guidance signs, and the like.

  As described above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

It is typical sectional drawing which shows the light-emitting body which concerns on the 1st Embodiment of this invention. FIG. 2A shows a measurement system for measuring the light intensity (illuminance) distribution in the direction perpendicular to the optical axis direction when the bulk type lens according to the first embodiment of the present invention is used. It is a schematic diagram. FIG. 2B is a schematic diagram showing a measurement system in the case of using a conventional biconvex lens for comparison with FIG. The intensity (illuminance) distribution along the y direction of the output light of each of the bulk lens, the thin lens (biconvex lens), and the bare light source 1 according to the first embodiment of the present invention is measured distance x = 1 m. It is a figure which shows the result at the time of measuring in. FIG. 4 summarizes data obtained by measuring the intensity (illuminance) distribution along the y direction similar to FIG. 3 while changing the measurement distance x. It is a figure which shows the relationship between the geometric structure of the bulk-type lens which concerns on the 1st Embodiment of this invention, and a condensing rate. 6 is a table showing the respective geometric structures (parameters) of each bulk lens shown in FIG. 5. It is typical sectional drawing which shows the light-emitting body which concerns on the modification of the 1st Embodiment of this invention. 8A to 8C are diagrams showing the relationship between the height Δ of the convex portion formed by the first lens surface and the beam intensity profile. 9A to 9C are diagrams showing the relationship between the height Δ of the convex portion formed by the first lens surface and the beam intensity profile. FIGS. 10A to 10C are views showing the relationship between the height Δ of the convex portion formed by the first lens surface and the beam intensity profile. It is a figure which shows the relationship between the height (DELTA) of the convex part which a 1st lens surface makes, and the flatness of illumination intensity. The outer diameter _{r e} of the bulk-type lens according to the first embodiment of the present invention 10 mm [phi, having a diameter of 15 mm, a schematic views showing the irradiance distribution at the measured distance x = 0.5 m when changing the 30 mm?. FIG. 13 is a diagram in which the measurement of FIG. 12 is performed in more detail, and the results are shown with the thickness between the inner wall portion and the outer wall portion of the bulk lens on the horizontal axis and the relative illuminance (arbitrary scale) on the vertical axis. It is the figure which showed the outer diameter / inner diameter ratio of the bulk type lens on the horizontal axis, and the relative illuminance (arbitrary scale) on the vertical axis. It is a figure which compares the intensity | strength (illuminance) distribution along the y direction of each output light when a back mirror is attached | subjected to the back surface part and outer side wall part of a bulk type lens, and when there is no back mirror. It is typical sectional drawing which shows the light-emitting body which concerns on the 2nd Embodiment of this invention. It is typical sectional drawing which shows the photodetector 50 which concerns on the 3rd Embodiment of this invention. 18A is a schematic cross-sectional view showing a light emitter according to the fourth embodiment of the present invention, and FIG. 18B is a schematic cross-sectional view showing a light receiver according to the fourth embodiment of the present invention. FIG. 19A is a schematic cross-sectional view showing a light emitter according to the fifth embodiment of the present invention. FIG. 19B is a first installation example thereof, and FIG. It is typical sectional drawing which shows the 2nd example of installation. It is typical sectional drawing which shows the light-emitting body 61 which concerns on the modification (modification 1) of the 5th Embodiment of this invention. It is typical sectional drawing which shows the light-emitting body 61 which concerns on the modification (modification 2) of the 5th Embodiment of this invention. It is a typical block diagram which shows the distance measurement system which concerns on the 6th Embodiment of this invention. It is typical explanatory drawing of the triangulation method used in the distance measuring system which concerns on the 6th Embodiment of this invention. It is typical sectional drawing which shows the light-emitting body which concerns on other embodiment of this invention. It is typical sectional drawing which shows the light-emitting body which concerns on other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2,2c, 2t, 2r, 2f Recessed ceiling part 3,3c, 3t, 3r, 3f Outer top part 4,4t, 4r, Lens medium 4d Inelastic lens medium 4f Flexible lens medium 5 Recessed side wall part 6,6t, 6r, 6f Housing 9 Photo diode chip 11, 51 First pin 12, 52 Second pin 13 LED chip 14, 14t, 14r Sealing resin 20, 22, 24, 25, 27, 28 Bulk lens 20f Flexible bulk type lens 30t, 30r Back support 31t, 31r Main support 32t, 32r Small rear mirror 40, 41 Protrusion 45 LED holder 50 Photo detector 55 Light receiving element holder 61 Light emitter 62 Drive unit 63 First power supply unit 71 Light receiving Body (Linear sensor)
72 Detection Unit 73 Calculation Unit 74 Output Unit 75 Second Power Supply Unit 81 Transparent Plate 82 Light-shielding Plate 83 Narrow Hole

Claims (2)

A bulk-type first lens medium having a first outer top, a first bottom, and an outer peripheral portion composed of side surfaces parallel to the first optical axis, and the first bottom to the first outer top. A first storage portion having a side wall portion formed of a surface parallel to the optical axis and provided in the first lens medium, a ceiling portion connected to the side wall portion, and the first storage portion A light emitter composed of a light source stored in a storage unit;
A bulk-type second lens medium having a second outer top, a second bottom, and an outer periphery comprising side surfaces parallel to the second optical axis; and from the second bottom to the second outer top. A second storage portion having a side wall portion formed in a plane parallel to the optical axis, and a ceiling portion connected to the side wall portion, provided in the second lens medium. A light receiving body configured to detect light from the light source housed in the housing portion, the ceiling portion and the side wall portion of the first housing portion being the first incident surface, the first The second outer top portion functions as a first light exit surface, the second outer top portion functions as a second light incident surface, and the ceiling portion and the side wall portion of the second storage portion function as a second light output surface. An optical information communication system.   2. The optical information communication system according to claim 1, wherein semiconductor light emitting elements having the same forbidden bandwidth and the same structure are used for the light source and the photodetector.

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