JP5677520B2 - LED light device - Google Patents

Description

The present invention relates to an LED lamp device.

2. Description of the Related Art In recent years, LED lamp devices using LEDs (Light Emitting Diodes) as general household lighting have become widespread. Some LED lamp devices of this type have the same external shape as filament type bulbs (hereinafter referred to as “LED bulbs”) so that they can be handled in the same manner as conventional filament type bulbs.

This LED light bulb is provided with an LED on a plug (support), and a hemispherical light-transmitting cover member (glass) is provided on the plug so as to cover the LED.

On the other hand, in Patent Documents 1 and 2, a solid object is surrounded by a mirror surface, a hole is formed in a part of the mirror surface, and the focal point of the mirror surface is set to be outside the hole. It is disclosed to form a virtual image.

JP 2006-343436 A Utility Model Registration No. 313576

However, the conventional LED bulb has a hemispherical cover, so only the outer shape is the same as that of the filament bulb, and the filament (light source) that lights up in the bulb cannot be seen. Therefore, there was a sense of incongruity compared with the conventional filament type light bulb.

In addition, the techniques of Patent Documents 1 and 2 are designed so that a three-dimensional object is raised in the air, and is not used as an electric lamp.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an LED lamp device in which a position that can be seen as a light source is seen as a position different from the position of an actual light source.

In order to solve the above problems, a first invention includes a light source, a support that supports the light source, and a light-transmitting cover member that is attached to the support and covers the light source, the light source being an LED, and a cover member The surface facing the light source is a concave curved reflecting surface, and the reflecting surface of the cover member has a focal point in the space between the support and the cover member for the light received from the light source. A virtual image is formed inside the cover member.

In the first invention, it is desirable that the reflecting surface of the cover member is substantially hemispherical and has a focal point at a position about half the radius of the hemispherical body. This is because a virtual image of the light source can be seen at substantially the center of the hemispherical cover member.

In the first invention, the reflection surface of the cover member has a substantially elliptical cross section, a light source is disposed at one focus of the ellipse, and a virtual image of the light source is formed at the other focus of the ellipse. It is desirable. This is because the virtual image of the light source can be seen inside the hemispherical cover member also with this configuration.

In the first aspect of the invention, it is desirable that the support body has a surface facing the cover member as a reflection surface. This is because a virtual image of the light source can be formed more clearly by providing a reflective surface also on the support member.

2nd invention is equipped with the light source, the support body which supports a light source, and the cover member which attaches to a support body and covers a light source, and the support body becomes a reflective surface with the concave curved surface on the side which supports a light source The cover member has a concave curved reflection surface on the surface facing the light source, and has a light transmission portion directly above the light source, and the reflection surface of the support and the reflection surface of the cover member are surfaces. It is symmetrical, and a virtual image of the light source is formed outside the cover member through the light transmission part of the cover member. The reflecting surface of the support and the reflecting surface of the cover member are curved surfaces having a substantially elliptical cross section. Further, a part of the light incident on the cover member is transmitted through the cover member and diffused to the outside of the cover member, and a part of the light incident on the cover member is reflected on the reflection surface of the cover member. It is characterized by. The reflectance is controlled by applying a reflective film to the reflective surface of the cover member. The reflecting surface of the support and the reflecting surface of the cover member are mirror surfaces that totally reflect.

According to the first invention, the virtual image of the light source is formed in the space between the cover member and the support member even though the light source is on the support. It looks as if it is in the inner space of the cover member.

According to the second aspect of the invention, since the light source is imaged in the space outside the cover member, the light source appears to be in a space away from the LED lamp device, and the illusion that the light source is floating in the air is brought about. Can do.

It is a longitudinal cross-sectional view of the LED lamp apparatus which concerns on 1st Embodiment of this invention. It is an optical path diagram of light explaining the imaging principle in the LED lamp device according to the first embodiment of the present invention. It is a graph explaining the reflectance of light. It is a longitudinal cross-sectional view of the LED lamp apparatus which concerns on the 1st modification of 1st Embodiment. It is a longitudinal cross-sectional view of the LED lamp apparatus which concerns on the 2nd modification of 1st Embodiment. It is a longitudinal cross-sectional view of the LED lamp apparatus which concerns on the form of 2nd Embodiment of this invention. It is a perspective view which shows the external appearance of the LED lamp apparatus which concerns on the form of 2nd Embodiment of this invention. It is sectional drawing which shows the usage example of the LED lamp apparatus which concerns on 2nd Embodiment.

The first embodiment of the present invention will be described below with reference to FIGS. The LED lamp device 1 according to the first embodiment is a bulb-type LED lamp device, and is attached to a support body (plug) 5 provided with a light source 3 at one end, as shown in FIG. And a cover member 7 that covers the light source 3.

The light source 3 is an LED module in which a number of LEDs are arranged in a plane, and is provided on the substrate 9. The substrate 9 is fixed to one side of the support 5 by screws (not shown).

A base 11 is provided on the other side of the support 5 and is connected to a commercial AC power source (socket) for general household use.

A drive substrate 13 for the light source 3 is provided between the base 11 and the light source 3, and an alternating current taken from the base 11 is converted into a drive current for the light source (LRD module) 3.

The support 5 has a reflective surface 15 that protrudes from the periphery of the light source 3 toward the cover member 7. The reflective surface 15 has a truncated cone shape and is inclined so as to increase in diameter from the light source 3 toward the cover member 7. ing. The reflecting surface 15 is a mirror in the present embodiment.

The cover member 7 has a hemispherical shape and is made of a light transmissive member such as transparent glass or transparent resin material. In this embodiment, the cover member 7 is a prism having a predetermined refractive index.

The inner surface (hemispherical concave surface) of the cover member 7 is a reflecting surface 17, and this reflecting surface 17 is a reflecting surface that the transparent material itself has, and the transparent body itself is a little without any special treatment such as coating. This is a reflection surface utilizing the characteristic of reflecting light.

Note that the reflective surface 17 of the cover member 7 may be coated or polished to increase the reflectance, or the cover member 7 may be made of a translucent member to increase the reflectance.

The reflection surface 17 of the cover member 7 has a concave substantially hemispherical surface so that the reflected light forms a focal point F at a distance f that is approximately ½ of the radius R of the spherical surface.

The reflecting surface 17 is not limited to a concave spherical surface, and may be a curved surface having a parabolic cross section or an elliptical concave curved surface (described later). In particular, the virtual image 3A is blurred or distorted due to aberration, but can be adjusted to some extent by making the reflecting surface 17 a paraboloid or an ellipsoid (rotation contrast aspheric surface). Further, the position and size of the virtual image 3A may be controlled by the light source position and the spherical curvature radius.

Next, the operation of the first embodiment will be described. In the LED lamp device 1, when the light source 3 is turned on, the light emitted from the light source 3 hits the cover member 7 and most of the light is transmitted through the cover member 7 and diverges.

Of the light traveling from the light source 3 toward the cover member 7, as shown in FIG. 1, a part of the light is reflected by the reflecting surface 17 of the cover member 7 toward the focal point and forms an image near the focal point F to form a virtual image 3A of the light source. It is formed.

In the present embodiment, the virtual image 3a of the light source 3 is not accurately focused at the focal point from the reflecting surface 17, and there is a slight shift in the focal point of the reflecting surface 17, so that it is not a clear outline but is blurred. It becomes a virtual image 3A of the outline.

Therefore, according to the first embodiment, the position seen as the light source of the LED lamp device 1 can be changed from the position of the actual light source 3 to the position of the virtual image 3, and the lit LED lamp device 1 is placed outside the cover member 7. From the perspective, the light source 3 appears to be in the inner space of the hemispherical cover member 7.

Here, with reference to FIG.2 and FIG.3, the principle etc. of the LED lamp apparatus 1 which concerns on this Embodiment are demonstrated. As shown in FIG. 2, when an optical axis is a straight line connecting the center C of the spherical mirror S and the center of the spherical mirror S, if the object O exists on this optical axis, the optical axis from the object O to the spherical mirror is along the optical axis. The distance is a, the distance from the spherical mirror S to the focal point of the spherical mirror S is f, and the distance along the optical axis from the spherical mirror S of the image O ′ of the object O formed by the spherical mirror S is b. The sign of each distance is in accordance with general optical practices, when measuring points a, b, and f along the optical axis to the right with a spherical mirror as the reference (origin) Is negative. Therefore, the above values are all negative values. According to optical paraxial theory, these quantities generally have the following relationship:

（１）式をｂについて解けば、下記（２）式となる。

If equation (1) is solved for b, equation (2) below is obtained.

In the formula (1), n and n ′ are the refractive indexes of the medium in which the object and the image exist, respectively. In the very general case where a mirror exists in the air, n = 1 and n ′ = − 1 are set.

Further, according to the paraxial theory, the image O ′ of the object O can be represented by the following equation (3) when the imaging magnification is m at the image position represented by the equation (1). .

ここで、ｍが負になる場合には倒立像が得られることを表す。また、球面鏡の場合には、その曲率半径をＲとする時（図２の場合はＲは負）下記式（４）により、焦点距離ｆが求められる。

Here, when m becomes negative, it means that an inverted image is obtained. In the case of a spherical mirror, when the radius of curvature is R (R is negative in the case of FIG. 2), the focal length f is obtained by the following equation (4).

From the above relationship, the cover member shown in FIG. 1 is not a spherical mirror, but it does not transmit all light and reflects a part of the light. The image 3A of the light source 3 shown in FIG. 1 is formed.

However, in reality, the light source surface image is not strictly formed by the imaging aberration of the spherical mirror, but forms an image as a lump of light having a vague extent. In this case, since Fresnel reflection from the almost spherical cover member 7 can be assumed, reflected light is generated at a fairly wide range of angles so as to penetrate the image 3A. Accordingly, it is felt that a person who has observed these has a light source having a certain size at the position of the image 3A.

Here, the light emitted from the light source 3 will be described. In consideration of the reflected light, there are basically four types of light (A) to (D).

(A) Illumination light that passes from the actual LED light source 3 through the cover member 7 and directly reaches the illuminated surface. Although depending on the reflectance of the cover member 7 (spherical glass), the strength is generally overwhelming. The light emission angle depends on the light emission intensity distribution of the LED and the structure of the lamp device 1.

(B) Illumination light that once reflects on the spherical surface of the cover member 7, forms an image 3 </ b> A, then reaches the cover member 7 again, passes through the cover member 7, and reaches the illuminated surface. The optical path largely depends on the light source position with respect to the spherical surface. Generally, it is observed in the side direction (circumferential direction) of the illumination system.

(C) Among the light that is Fresnel-reflected by the cover member 7 and imaged 3A, there is illumination light that does not reach the cover member 7 directly depending on the angle but reaches the reflector 15 surrounding the LED light source 3. This light is reflected relatively forward, but this is different in intensity ratio from the reflected light generated in a general illumination system having a light source in the image 3A and having a reflection surface behind it. It is the same illumination light.

(D) Of the light that is Fresnel-reflected by the cover member 7 and imaged 3A, the light that is neither (B) nor (C), that is, the light that is reflected by the relatively spherical glass head, and the reflected light is the LED light source part. There is illumination light coming back to. Although it depends on the reflection characteristics of the light source surface, a considerable amount of energy appears to be diffused or irregularly reflected.

Next, the reflectance (Fresnel reflectance) intensity will be described with reference to the graph of FIG. In general, light exhibits a refraction / reflection phenomenon at a boundary surface between dielectrics such as air, water, and glass. The ratio of the intensity of the reflected light at that time (Fresnel reflection intensity) is shown in FIG. 3. In FIG. 3, the intensity of the remaining light is transmitted and refracted.

In the relationship of FIG. 3, it is assumed that light travels from a medium having a refractive index of 1 to a medium having a refractive index of 1.5. Originally, the polarization direction of light, s component, and p component must be considered separately (reflectance of each component in the figure is indicated by Rs, Rp), but in a general light source, the polarization state of the light wave emitted therefrom Is random, and the average value (Rs + Rp) / 2 indicated by the dotted line in the figure is a reference. It can be seen from FIG. 3 that about 4% of the light is reflected even if it is incident perpendicularly to the curved tangent plane (incident angle is 0 degree).

That is, in the present embodiment, even if the cover member 7 is not subjected to a coating process or the like for increasing the reflectance, the reflected light can be obtained although it is a slight amount of light due to the characteristics of the transparent body itself.

Further, if the incident light is perpendicular to the dielectric boundary surface, only about 4% of the reflection occurs. Therefore, for example, if a minute light source exists at the center of curvature of the sphere of the cover member 7, all the light is perpendicular to the spherical surface. Will be incident on. If it does not deviate significantly from this arrangement, 4 to 5% can be used as a measure of the reflectance. Therefore, if a spherical surface made of glass having a refractive index of about 1.5 is used as the cover member 7, the pseudo light source 3A has a brightness of only about 5% of the illumination light (A) described above. If the pseudo light source 3A is formed with a large proportion of light, the cover member may be provided with a reflection-enhancing film on the entire spherical surface or part of the surface. In this way, the illumination light (A) of the light source 3 and The ratio of the light (B), (C), and (D) after forming the pseudo light source 3A can be controlled. However, in this case, since the ratio of reflection increases, it is necessary to consider the second reflected light reflected again by the cover member 7.

Since the paraxial imaging formula (formulas (1) to (4)) described above is established even if the object and the image are interchanged, among the light that passes through the pseudo light source 3A and reaches the reflection surface of the cover member 7 again, Most of the light reflected again by Fresnel returns to the vicinity of the light source 3. Since the light (D) in the case of a single reflection also returns to the light source 3, it is desirable to take measures to prevent the illumination surface itself from being highly reflective, absorbing, and unpleasant stray light.

Next, a modification of the first embodiment will be described. In the modified examples and other embodiments described below, parts having the same operational effects as those of the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted. In the following description, differences from the first embodiment will be mainly described.

FIG. 4 shows an LED lamp device 1 according to a first modification of the first embodiment. In the first modification, the cover member 7 has an elliptical cross section, the light source 3 is disposed at one focal point f1 of the ellipse, and a virtual image of the light source is formed at the other focal point f2 of the ellipse. It has been made. This first modification can also provide the same operational effects as those of the first embodiment described above.

FIG. 5 shows an LED lamp device 1 according to a second modification. The second modification differs from the first modification in that the elliptical cover member 7 is substantially half in the first modification, and a planar reflecting surface 15 is provided on the LED light source 3 side. In the second modified example, the elliptical surface is halved, and the peripheral portion of the LED light source 3 is a planar reflecting surface 15, so that the manufacture is easier than in the first modified example.

Next, a second embodiment of the present invention will be described with reference to FIGS.

The LED lamp device 1 according to the second embodiment includes a light source 3, a support 5 that supports the light source 3, and a cover member 7 that is attached to the support 5 and covers the light source 3.

The support 5 has a reflective surface 21 on the surface (inner surface) on which the light source 3 is placed, and the reflective surface 21 of the support 5 forms a concave surface having a substantially semi-elliptical cross section. .

The reflection surface 17 of the cover member 7 is a reflection surface having substantially the same shape as the support 5 and has a concave surface with a substantially semi-elliptical cross section. Therefore, as shown in FIG. 6, the reflecting surface 21 of the support 5 and the reflecting surface 17 of the cover member 7 form a curved surface having a substantially elliptical cross section as a whole.

The light source 3 is disposed substantially at the center of the reflecting surface 21 of the support member 5, and a light transmitting portion 21 with a hole is formed at a position facing the light source 3 in the cover member 7.

In the second embodiment, the reflection surface 21 of the support member 5 and the reflection surface 17 of the cover member 7 are mirror surfaces that totally reflect.

The reflection surface 21 of the support member 5 has a focal point that forms an image outside the light transmission portion 21 of the cover member 7.

According to the second embodiment, as indicated by a one-dot chain line in FIG. 6, the light source 3 is reflected by the reflection surface 17 of the support member after being reflected by the reflection surface 17 of the cover member 7. The reflected light exits the light transmission part 23 and forms a virtual image 3A outside the cover member 7. Therefore, as shown in FIG. 7, when the LED lamp device 1 is viewed from the outside, the virtual image 3A of the light source in the air seems to emit light.

For example, as shown in FIG. 8, the LED light device 1 according to the second embodiment is embedded in the ground along the side of the promenade N, so that the light source 3 that illuminates the feet floats in from the ground. It becomes a virtual image 3A and can appear to be floating in the air, giving a fantastic feeling.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

For example, in the first embodiment, the reflecting surface 15 of the support 5 may be omitted.

In the second embodiment, the light transmitting portion 23 is not limited to forming a hole, and the hole portion may be made of transparent glass or a transparent resin material.

The LED lamp device 1 according to the first embodiment is not limited to indoor lighting, but may be used as a street lamp, or the LED lamp device 1 according to the second embodiment is used as an indoor lighting device. It may be used.

DESCRIPTION OF SYMBOLS 1 LED lamp apparatus 3 Light source 5 Support body 7 Cover member 17 Reflective surface 21 of cover member Reflective surface 23 of support body Light transmission part

Claims (16)

An LED light source, a support that supports the LED light source, and a light-transmissive cover member that is attached to the support and covers the LED light source, the surface of the cover member facing the light source is a concave curved reflecting surface And the reflective surface of the cover member reflects the light received from the LED light source and has a focal point in the space between the support and the cover member,
A part of the light from the LED light source passes through the cover member and diverges outside the cover member, and a part of the light from the LED light source is reflected on a reflection surface of the cover member, and the reflected light and Forming an image of the LED light source with the light from the LED light source inside the cover member;
Part or all of the imaged light is further incident on the cover member, and part of the light is transmitted through the cover member and diverges outside the cover member. The LED lamp device, wherein the LED lamp device is disposed at a position equal to or lower than a lower position of the cover member. 2. The LED lamp device according to claim 1, wherein the image is formed at an upper portion than a lower position of the cover member. An LED light source, a support that supports the LED light source, and a light-transmissive cover member that is attached to the support and covers the LED light source, the surface of the cover member facing the light source is a concave curved reflecting surface And the reflective surface of the cover member reflects the light received from the LED light source and has a focal point in the space between the support and the cover member,
A part of the light from the LED light source passes through the cover member and diverges outside the cover member, and a part of the light from the LED light source is reflected on a reflection surface of the cover member, and the reflected light and Forming an image of the LED light source with the light from the LED light source inside the cover member;
Part or all of the imaged light is further incident on the cover member, and part of the light is transmitted through the cover member and diverges outside the cover member. The LED lamp device is arranged at a position lower than the equator position of the cover member. The imaging is characterized by being formed above the equator position of the cover member, LED lamp device according to claim 3. An LED light source, a support that supports the LED light source, and a light-transmissive cover member that is attached to the support and covers the LED light source, the surface of the cover member facing the light source is a concave curved reflecting surface And the reflective surface of the cover member reflects the light received from the LED light source and has a focal point in the space between the support and the cover member,
A part of the light from the LED light source passes through the cover member and diverges outside the cover member, and a part of the light from the LED light source is reflected on a reflection surface of the cover member, and the reflected light and Forming an image of the LED light source with the light from the LED light source inside the cover member;
Part or all of the imaged light is further incident on the cover member, and part of the light is transmitted through the cover member and diverges outside the cover member. In the portion where the light from the LED light source in the LED lamp device diverges outside the LED lamp device, that is, in the portion where the light from the LED light source enters the cover member and diverges outward from the cover member An LED lamp device, wherein the LED lamp device is arranged at the same position as the lowest part or at a lower position. The LED lamp device according to claim 5, wherein the image is formed at an upper portion than a lowest portion among the portions diverging outward from the cover member. The reflective surface of the cover member is a curved surface with a part below the center of a substantially spherical surface cut out, and has a focal point at a position about 1/2 of the radius of the curved body. 6. The LED lamp device according to 6. The LED lamp device according to claim 1, wherein the reflection surface of the cover member is a substantially hemispherical surface, and has a focal point at a position about a half of the radius of the hemisphere. The LED light source exists on the optical axis with a straight line connecting the center of the equator of the cover member and the center of the spherical surface or hemispherical surface, from the LED light source to the surface center of the spherical surface or hemispherical surface. The distance on the optical axis is a, the distance from the focal point on the optical axis of the cover member to the surface center of the spherical surface or hemispherical surface is f, and from the surface center of the spherical surface or hemispherical surface to the image of the LED light source Where b is the distance on the optical axis of
n ′ / bn / a = n ′ / f
(Where n and n ′ are the refractive index of the medium in which the LED light source and imaging are respectively present)
The LED device according to claim 1, wherein the LED device is dimensionally designed so that The LED light source is disposed approximately in the middle between the approximate center of the spherical body and the virtual lower end of the spherical body, or approximately in the middle between the approximate center of the hemispherical body and the lower end of the hemispherical virtual sphere. The LED device according to claim 1, wherein the LED device is formed. The reflection surface of the cover member is a surface having a substantially elliptical longitudinal section, or a curved surface with a part below the center of the approximately elliptical shape, or a curved surface with a portion above the center of the approximately elliptical shape, The LED device according to claim 1, wherein a light source is arranged at one focus of the ellipse, and an image of the light source is formed at the other focus of the ellipse. The said support body has an LED support body which mounts LED, and a planar reflective surface in the surrounding part, The said reflective surface is an opposing surface of the said cover member, It is characterized by the above-mentioned. The LED device according to any one of ˜11. The support body has an LED support body on which an LED is mounted and a frustoconical reflection surface around the LED support body, and the reflection surface is an opposing surface of the cover member, from the LED support body to the cover member It inclines so that a diameter may be expanded toward the side, The LED device of any one of Claims 1-11 characterized by the above-mentioned. An LED light source in which a plurality of LEDs are arranged in a plane, a support that supports the LED light source, and a cover member that is attached to the support and covers the LED light source;
The support has a concave curved reflective surface on the side that supports the LED light source,
The cover member has a concave curved reflection surface on the surface facing the LED light source, and has a light transmission part directly above the LED light source,
The reflective surface of the support and the reflective surface of the cover member are in a plane symmetry relationship,
An LED lamp device characterized in that an image of the LED light source is formed outside the cover member through a light transmission portion of the cover member. 15. The LED lamp device according to claim 14, wherein the reflecting surface of the support and the reflecting surface of the cover member are curved surfaces having a substantially elliptical cross section. A part of the light incident on the cover member is transmitted through the cover member and diffused to the outside of the cover member, and a part of the light incident on the cover member is reflected on the reflection surface of the cover member. The LED lamp device according to claim 14 or 15.

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