JP5586119B2 - Optical component and illumination device using the same - Google Patents

Description

  The present invention relates to an optical component including a lens and a reflecting mirror for condensing light emitted from a light source such as a light emitting diode and irradiating it forward, and an illumination device using the optical component.

  In order to efficiently collect light emitted from a light emitting diode or the like and irradiate it forward, a structure in which an appropriate collimating lens is formed at the tip is often used. For example, the illumination device 1 ′ shown in FIG. 16A includes a cap 5 and a lens 7 made of metal. A light emitting diode chip 20 is fixed on the lead / stem 18a and connected to the other lead 18b. The light emitted from the light-emitting diode chip 20 is collected by a glass lens 7 and emitted as parallel rays (Patent Document 1).

  However, in the illuminating device 1 ′ having the structure as shown in FIG. 16A, since the effective use range θ of the light beam irradiated so as to be parallel rays is not wide, a considerable part of the light emitted from the light emitting diode chip 20 is obtained. There was a problem that it could not be derived in the front direction. Therefore, in the example shown in FIG. 16B, an optical component 2 'having a different shape is used. This optical component 2 ′ has a generally bowl-shaped overall shape with a flat front surface and a curved peripheral side surface, a recess is provided in the center of the rear surface, and the light emitting diode chip 20 is disposed in the recess. ing. The bottom surface of the concave portion rises in a parabolic shape to form a lens 3 ′, and the peripheral surface of the optical component 2 ′ is a reflecting mirror 4 ′ that reflects the radiation beam from the light emitting diode chip 20. If such an optical component 2 ′ is used, a portion of the luminous flux emitted from the light emitting diode chip 20 that has not been taken in by the lens 3 ′ is reflected by the reflecting mirror 4 ′ and emitted as parallel rays from the front surface.

JP-A 61-147585

  However, in the illumination device 1 ′ as shown in FIGS. 16A and 16B, there is a problem that an electrode pattern or the like of the light-emitting diode chip 20 that is a light source appears when the object is irradiated with light. This problem will be described by taking a case where the light emitting diode chip 20 is formed on an insulating substrate as an example.

  For example, in a light-emitting element such as a gallium nitride-based light-emitting diode chip, since there are few conductive substrates on which a semiconductor can be grown with good crystallinity, the semiconductor is often grown on an insulating substrate such as sapphire. FIG. 17 is a plan view showing an example of such a light-emitting diode chip 20. An n-type nitride semiconductor layer 30 is formed on an upper surface of an insulating substrate (not shown) such as sapphire, and a p-type nitride semiconductor layer 31 is further formed. An n-pad electrode 36 is formed on the n-type nitride semiconductor layer 30 where the p-type nitride semiconductor layer 31 is removed. On the other hand, a translucent electrode 34 is formed on almost the entire surface of the p-type nitride semiconductor layer 34, and a p-pad electrode 32 is formed thereon. A wire 24 such as a gold wire is bonded on the n pad electrode 36 and the p pad electrode 32, and a bonding ball 25 is formed when bonded. This light emitting diode chip emits light from the entire upper surface, but the light emission state is not uniform. That is, since a large amount of current flows on the translucent electrode 34, the light emission intensity is strong. On the other hand, the n pad electrode 36, the p pad electrode 32, the wire 24, and the bonding ball 25 do not transmit light. Is very low.

  However, in the illuminating device 1 ′ as shown in FIGS. 16A and 16B, the collimating lens 7 and the optical component 2 are focused on the light emitting diode chip 20 so as to be collimated and irradiated in the forward direction. The light emitting pattern of the light emitting diode chip is projected as it is onto the irradiated object. Therefore, for example, as shown in FIG. 18, when the light emitting diode chip 20 shown in FIG. 17 is incorporated in the illumination device 1 ′ shown in FIG. 16A or B and irradiated onto the screen 44, light is emitted in the spots 46 formed by the irradiation. The electrode pattern or the like of the diode chip 20 is projected. Such a phenomenon lowers the quality of the illumination device as an irradiation light source and also limits the applications that can be used.

  Accordingly, the present invention provides an optical component and an illumination device that can prevent a pattern of a light source such as a light emitting diode from appearing in an irradiation image while maintaining a high light utilization rate, and obtain a substantially isotropic and bright irradiation image. For the purpose.

  In order to solve the above problems, an optical component of the present invention includes a lens and a reflecting mirror having a rotating curved surface, and condenses emitted light from a light source disposed behind the lens by the lens and the reflecting mirror. And the focal point of the lens is deviated forward from the focal point of the reflecting mirror.

  The illuminating device of the present invention is an illuminating device including the optical component of the present invention and a light source, and the focal point of the reflecting mirror is on the light source, while the focal point of the lens is in front of the light source. It is located in.

  The optical component and the illumination device according to the present invention are characterized in that the focal point of the reflecting mirror is on the light source, while the focal point of the lens is located in front of the focal point of the reflecting mirror. Accordingly, it is possible to prevent the light emission pattern of the light source from being projected onto the irradiated object as it is while capturing the light emission of the light source with high efficiency. This utilizes the difference in optical characteristics between the lens and the reflecting mirror. In other words, the lens has the property of inverting the image of the light source at the focal position and projecting it on the screen, while the rotating curved reflector reflects the image of the light source at the focal position on the screen while rotating infinitely. Has the property of projecting. Accordingly, in order to prevent the light emission pattern of the light source from being projected onto the irradiated object as it is, the focal position of the lens may be shifted from the light source, and the focal point of the reflecting mirror may coincide with the light source. And by making the focus of a reflective mirror correspond to a light source, the condensing rate by a reflective mirror can be raised and the fall of the light utilization factor of a light source can be suppressed. Therefore, according to the optical component and the illumination device of the present invention, it is possible to prevent the light source pattern from being projected onto the irradiated object while capturing the light emission of the light source with high efficiency, and to obtain a substantially isotropic and bright irradiation image. It is done.

  The optical component used in the present invention can take various forms.For example, the optical component protrudes rearward and has a protrusion in which a light source is to be disposed at the protrusion, and the lens is formed on the bottom surface of the recess. The reflecting mirror is preferably formed on the peripheral surface of the protruding portion. With such a configuration, the optical component can be molded integrally. If the optical component can be molded integrally, the mounting and adjustment of the optical component becomes easy. Moreover, it is preferable that the optical component is integrally formed of glass or resin.

  Further, in the optical component having such a configuration, it is preferable to form a reflective film made of a material having high reflectivity such as Al (aluminum), Ag (silver) or the like on the peripheral surface of the protruding portion. Thereby, the reflectance of the reflecting mirror can be increased and a brighter irradiation image can be obtained.

  Moreover, the light source in this invention can be various light sources, such as a light emitting diode, a light bulb, a fluorescent lamp, and an HID lamp. Among these, a light emitting diode is preferable. Since the light emitting diode is small, can emit light with high luminance, and has a long lifetime, the light emitting diode can be a small, high luminance, and long-life lighting device. In this specification, when simply referred to as a light emitting diode, it includes both a light emitting diode chip and a light emitting device on which the light emitting diode chip is mounted. A light emitting diode chip refers to a light emitting diode in the form of a semiconductor chip, and a light emitting device refers to a light emitting diode chip incorporated in a package with leads. When the light source is a light emitting device, the positional relationship between the focal point of the lens or reflecting mirror in the optical component and the light source is considered based on the light emitting diode chip in the light emitting device. Further, an appropriate optical system such as a lens may be formed in a package such as a light emitting device.

  Moreover, it is preferable that the light source of this invention is equipped with a light emitting element and the translucent dome-shaped member formed on the light emitting element. A light emitting element is an element that takes on a light emitting function in a light source. In the light emitting device, a light emitting diode chip corresponds to a light emitting element. By forming the translucent dome-shaped member, it is possible to increase the light extraction efficiency of the light source and to compensate for the decrease in the light collection rate caused by shifting the focal point of the lens from the light source. That is, when the dome-shaped member is formed, the incident angle at which the light emitted from the light emitting element in the light source is incident on the interface between the dome-shaped member and the air becomes small, so the ratio of the light returning to the inside of the light source by reflection is reduced. For this reason, the light extraction rate of the light source can be improved.

  In the present specification, the focal point of the reflecting mirror is positioned on the light source, not only when the focal point and the light source are exactly coincident, but also when the focal point and the light source are shifted, a decrease in the light collection rate is a practical problem. Including the case where it is insignificant. On the other hand, the fact that the focal point of the lens is located in front of the focal point of the reflecting mirror means that the condensing rate of the lens itself is deviated to a significant degree.

  Further, in this specification, “front” or “front” refers to the direction toward the light exit side or the surface on the exit side, and “rear” or “rear surface” refers to the direction toward the light incident side or The surface on the incident side.

  In this specification, that a certain member is “translucent” means that light can be transmitted through the member to such an extent that light emission can be observed, and is not necessarily transparent and colorless. For example, even if it is opaque including a diffusing material, it is “translucent” if it can transmit light emitted from a light source.

  As described above, according to the optical component and the illumination device of the present invention, while maintaining a high light utilization rate, a pattern of a light source such as a light emitting diode is prevented from appearing in an irradiation image, and isotropic and bright irradiation An optical component and an illuminating device from which an image can be obtained can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1A is a perspective view showing the lighting apparatus according to Embodiment 1 of the present invention, and FIG. 1B is a cross-sectional view taken along the line BB ′. 2 is an exploded perspective view of the lighting device 1 shown in FIG. 1A. As shown in FIG. 2, the illuminating device 1 includes three parts: an optical component 2, a holder 5, and a light emitting unit 8.

As shown in FIG. 2, the light emitting unit 8 includes a light emitting device 6 (light source) on a substrate 9 made of a metal having good thermal conductivity such as aluminum. A wiring pattern is formed inside the substrate 9 (not shown). The wiring pattern electrically connects the positive electrode and the negative electrode exposed on the bottom surface of the light emitting device 6 to the external lead wires 14a and 14b. ing. 1A and 1B, the light emitting unit 8 can be fixed to the heat radiating plate (heat sink) 10 using an appropriate fixing member such as a screw 12. The heat generated from the light emitting device 6 is transmitted to the heat radiating plate 10 through the substrate 9 and released to the outside.

  The light emitting device 6 mounted on the light emitting unit 8 has a structure as shown in FIG. 3, for example. That is, the light emitting diode chip 20 as a light emitting element is placed in the concave opening 16a of the package 16, and is connected to the positive and negative lead electrodes 18a and 18b embedded in the package 16 by wires 24 such as gold wires. Has been. The light emitting diode chip 20 can be, for example, a gallium nitride light emitting diode chip having a structure as shown in FIG. The light emitting diode chip 20 is sealed with a light-transmitting sealing resin 22 such as epoxy or silicone.

  As shown in FIGS. 1A and 1B, the holder 5 serves to fix the optical component 2 to the upper surface of the light emitting unit 8. The holder 5 of the present embodiment is made of a flexible material such as plastic or resin, and the optical component 2 can be detachably fixed to the light emitting unit 8 by claw portions formed on the upper surface and the lower surface.

  As shown in FIG. 4, the optical component 2 has an overall shape of a substantially saddle system, and the front surface 2a is flat, while the rear surface is formed with a mountain-shaped protrusion 2b. A concave portion 2c is formed at the tip of the mountain-shaped protruding portion 2b in order to place the light emitting device 6. The bottom surface of the recess 2 c has a curved surface capable of exhibiting an appropriate lens effect, preferably a convex aspherical shape, more preferably a free curved surface or a conic surface (for example, a parabolic surface). ing. Further, the peripheral surface of the mountain-shaped projecting portion 2 b is formed of a suitable rotating curved surface, preferably a rotating paraboloid, and constitutes the reflecting mirror 4.

  As shown in FIG. 1B, the optical component 2 is fixed by the holder 5 so that the light emitting device 6 is positioned in the concave portion 2c on the rear surface. At this time, the optical axis of the lens 3 formed on the bottom surface of the recess 2c is preferably perpendicular to the light emitting surface of the light emitting device 6 and passes through the center of the light emitting surface. As shown in FIG. 1B, a part of the light emitted from the light emitting device 6 is condensed by the lens 3 and is emitted from the front surface 2a of the optical component as a parallel light beam. Most of the remaining light that is not collected by the lens 3 is slightly refracted when passing through the side wall of the recess 2c, and then reflected by the peripheral surface 4 (= reflecting mirror 4) of the mountain-shaped protrusion 2b. Parallel rays are emitted from the front surface 2 a of the optical component 2.

  The feature of the optical component 2 of the present invention is that the focal point of the reflecting mirror 4 formed on the peripheral surface of the mountain-shaped protrusion 2b is on the light emitting device 6, more specifically, on the light emitting diode chip 20 in the light emitting device 6. In contrast, the focal point of the lens 3 formed on the bottom surface of the recess 2 c is shifted forward from the focal point of the reflecting mirror 4. Thereby, it is possible to prevent the light emission pattern of the light emitting diode chip 20 from being projected onto the irradiated object as it is while capturing light emitted from the light emitting diode chip 20 with high efficiency.

  This technical effect utilizes the difference in optical characteristics between the lens 3 and the reflecting mirror 4. That is, the lens 3 has the property of inverting the image of the light source at the focal position and projecting it onto the screen, while the rotating curved reflector 4 rotates the screen while rotating the infinitely divided image of the light source at the focal position. It has the property of projecting on top. For example, when the four reflecting mirrors are arranged in a square and projected, the properties of the rotating curved reflector 4 are in principle formed by overlapping the light source images while rotating by 90 degrees. The same as above. Therefore, in order to prevent the emission intensity distribution of the light source from being projected onto the irradiated object, the focal position of the lens 3 may be shifted from the light source, and the focal point of the reflecting mirror 4 may be coincident with the light source. Then, by making the focal point of the reflecting mirror 4 coincide with the light source, it is possible to increase the light collection rate by the reflecting mirror 4 and suppress the decrease in the light utilization rate of the light source. Therefore, according to the optical component 2 of the present invention, it is possible to obtain an excellent effect that the pattern of the light source can be prevented from being projected onto the irradiation object while capturing the light emission of the light source with high efficiency.

Hereinafter, this point will be described in more detail with reference to FIGS.
FIG. 5 is a schematic diagram showing the positional relationship between the focal point of the optical component 2 and the light-emitting diode chip 20 in the present embodiment. First, the focal point of the lens 3 formed on the bottom surface of the recess 2c is shifted forward from the light emitting diode chip 20 and is inside the recess 2c. On the other hand, the focal point of the reflecting mirror 4 formed on the peripheral surface of the mountain-shaped protrusion 2 b of the optical component 2 is on the light emitting diode chip 20. On the other hand, FIG. 8 shows the relationship between the focal point of the optical component 2 ′ and the light emitting diode chip 20 in the comparative embodiment, not the embodiment of the present invention. In the optical component 2 ′ shown in FIG. 8, the focal points of the lens 3 ′ and the reflecting mirror 4 ′ are both on the light emitting diode chip 20.

  The spot images formed on the screen when irradiated with a screen 1 m away using the optical component 2 of the present embodiment are shown in FIGS. 6A to 6C when irradiated with the optical component 2 ′ of the comparative embodiment. Spot images are shown in FIGS. 6A and 9A show images formed by the reflecting mirrors 4 and 4 ′, FIGS. 6B and 9B show images formed by the lenses 3 and 3 ′, and FIGS. 6C and 9C show images obtained by combining them. Indicates. Therefore, an image as shown in FIGS. 6C and 9C appears on the actual screen.

  Further, FIG. 7 shows an illuminance distribution graph on the screen when the screen is irradiated using the optical component 2 of the present embodiment, and the illuminance distribution on the screen when irradiated using the optical component 2 ′ of the comparative embodiment. A graph is shown in FIG. 7 and 10, reference numerals 38 and 38 ′ are images formed by the reflecting mirrors 4 and 4 ′, reference numerals 40 and 40 ′ are images formed by the lenses 3 and 3 ′, and reference numerals 42 and 42 ′ are the combined images. An illuminance distribution graph is shown. 6 to 7 and FIGS. 9 to 10 show the distribution on the premise that the light emission distribution on the surface of the light-emitting diode chip 20 is uniform for the sake of simplicity of the drawings.

  First, attention is focused on the image formed on the screen by the reflecting mirrors 4 and 4 '. The focal positions of the reflecting mirrors 4 and 4 ′ are on the light emitting diode chip 20 in any form. Accordingly, the image formed by the reflecting mirror 4 of the present embodiment is the same as the image formed by the reflecting mirror 4 'of the comparative embodiment. As described above, the rotationally curved reflecting mirrors 4 and 4 'have a property of projecting the image of the light source at the focal position onto the screen while rotating infinitely. Accordingly, as shown in FIGS. 6A and 9A, only the concentric intensity distribution is formed on the image formed on the screen by the reflecting mirrors 4 and 4 ′, and the pattern of the light emitting diode chip 20 does not appear. . Further, as shown in the graph 38 in FIG. 7 and the graph 38 ′ in FIG. 10, the images formed by the reflecting mirrors 4 and 4 ′ have a somewhat broad illuminance distribution.

  Next, attention is focused on the image formed by the lenses 3 and 3 'on the screen. In the comparative form shown in FIG. 8, the focal point of the lens 3 ′ is located on the light emitting diode chip 20. Therefore, the lens 3 'projects the rectangular shape of the light emitting diode chip 20 onto the screen as it is as shown in FIG. 9A. Further, as shown in FIG. 10, the image (graph 40 ') formed by the lens 3' is more strongly distributed in the center than the image (graph 38 ') formed by the reflecting mirror 4', and the illuminance near the center is also considerably high. strong. For this reason, as shown in FIG. 9C, the rectangular shape of the light-emitting diode chip 20 also appears strongly in the image obtained by combining the image of the lens 3 ′ and the image of the reflecting mirror 4 ′. As described above, the actual light emitting diode chip 2 ′ has an electrode pattern as shown in FIG. 17 and has a light emission intensity distribution according to the electrode pattern. Therefore, in the optical component 2 ′ as in the comparative example, an electrode pattern as schematically shown in FIG. 18 appears on the screen.

  On the other hand, in the optical component 2 of the present embodiment shown in FIG. 5, the focal point of the lens 3 is located in front of the light emitting diode chip 20. For this reason, as shown in FIG. 7, unlike the image formed by the reflecting mirror 4 (graph 38), the image formed by the lens 3 (graph 40) has a substantially rectangular illuminance distribution and is substantially uniform over the entire range. . Further, as shown in FIG. 6A, the pattern of the light emitting diode chip 20 hardly appears in the image formed by the lens 3 on the screen. For this reason, as shown in FIG. 6C, the pattern of the light emitting diode chip 20 is hardly projected on the image after the synthesis with the image of the reflecting mirror 4. Therefore, even in the light-emitting diode chip 20 having the electrode pattern as shown in FIG. 17, the emission intensity distribution according to the electrode pattern does not appear on the screen, and an isotropic high-quality irradiation image can be obtained. it can.

Next, each configuration of the illumination device according to the present embodiment will be described in detail.
(1) Optical component 2
The optical component 2 in the present invention is an optical component that condenses the emitted light of the light source disposed on the rear surface by the lens and the reflecting mirror and emits the light from the front surface, and the focal point of the reflecting mirror is at a position where the light source can be disposed. Any lens may be used as long as the focal point of the lens is shifted forward from the focal point of the reflecting mirror. Therefore, various forms are possible without being limited to the form shown in FIG. For example, the reflector and the lens may be separable. However, from the viewpoint of manufacturing cost, easy assembly, etc., the entire optical component 2 is preferably integrally molded. The optical component 2 is preferably manufactured using a material having translucency with respect to light emission of a light source, such as glass, PMMA (polymethacrylate) resin, and PC (polycarbonate) resin.

(Lens 3)
In the example shown in FIG. 4, a free-form convex lens 3 is formed in the concave portion 2c, and the front surface 2a of the optical component 2 is flat. Thus, the lens 3 functions as a collimating lens that emits parallel light. However, the lens 3 only needs to have a focal point in front of the light source, and is not limited to the free-form convex lens 3 as shown in FIG. For example, a desired lens effect may be exhibited by combining the front surface 2a of the optical component with a curved surface and a curved surface formed on the bottom surface of the recess 2c. The lens 3 is not limited to a collimating lens that produces parallel light, and can be a lens having desired optical characteristics depending on the purpose.

  The focal position of the lens 3 is placed in front of the focal position of the reflecting mirror 4, but the amount of deviation between the focal position of the lens 3 and the focal position of the reflecting mirror 4 can be adjusted depending on the type of light source used.

(Reflector 4)
In the example shown in FIG. 4, the peripheral surface of the mountain-shaped projecting portion is a paraboloid and the peripheral surface functions as the reflecting mirror 4. Thereby, the light emitted from the light source at the focal point of the reflecting mirror 4 becomes parallel light and is emitted from the front surface 2a of the optical component. Note that the reflecting mirror 4 has a rotating curved surface, and it is sufficient that the focal point is on the light source, and various shapes can be employed. For example, a curved surface that generates light other than parallel light may be used depending on the purpose. Further, the focal position of the reflecting mirror 4 is preferably arranged in the vicinity of the opening of the recess 2c, more preferably slightly inside from the opening of the recess 2c. As a result, the light emitted from the light source can be incident on the reflecting mirror 4 without leakage, and the capture efficiency is improved.

  Further, when the peripheral surface of the mountain-shaped protrusion 2b formed on the optical component 2 is the reflecting mirror 4, the interface between the peripheral surface of the mountain-shaped protrusion 2b and the air may be used as it is, or the mountain-shaped protrusion A reflective film made of a material having a high reflectivity with respect to light from the light source may be formed on the peripheral surface of 2b. For example, the reflective film is preferably made of Al (aluminum), Ag (silver), or the like.

(2) Holder 5
The holder 5 only needs to be able to fix the optical component 2 on the light emitting unit 8, and is not limited to the one shown in FIG. 1A or FIG. The material can also be various materials such as metal, plastic, rubber, and resin. Among these, it is preferable to form from a flexible material such as plastic or rubber. In addition, as shown in FIG. 2, it is preferable to form claw portions on the upper surface and / or the lower surface because it can be detachably attached to the optical component 2 and the light emitting unit 8 without using screws or the like.

(3) Light emitting unit 8
(Substrate 9)
The substrate 9 for fixing the light emitting device 6 as a light source is preferably formed of a material having high thermal conductivity such as Al (aluminum), Cu (copper) or the like. Thereby, the heat conduction to the heat sink fixed to the lower side of the substrate 9 can be improved, and the heat dissipation efficiency of the light emitting device 6 can be improved. The substrate 9 may also serve as a lead for supplying external power to the light emitting device 6. In that case, it is preferable to form a wiring pattern by forming a multilayer structure through an appropriate insulating layer.

(Light source: light emitting device 6)
In this embodiment, the case where the light source 6 is a light emitting device as shown in FIG. 3 has been described as an example. However, the light source is not limited to this, and various light sources such as a light bulb, a fluorescent lamp, and an HID lamp are used. Can do. The present invention is particularly effective for a light source having a certain area of light emitting surface and an in-plane distribution of light emission intensity.

  As the light source, the light emitting device 6 as shown in FIG. 3 is preferable because it can be a small and high-luminance lighting device. The light-emitting device 6 includes a support (a package 16 in FIG. 3), a light-emitting element (a light-emitting diode chip 20 in FIG. 3), a translucent member (a sealing resin 22 in FIG. 3), and a connection conductor (in FIG. 3). In FIG. 3, it is preferable to provide a wire 24) and the like. Furthermore, it is preferable to include a wavelength conversion member (not shown) that converts the wavelength of part of the light emitted from the light emitting element 20. In addition to the light emitting element 20, the support 16 can be mounted with a light receiving element and a protective element (for example, a Zener diode or a capacitor) that protects these semiconductor elements from destruction due to overvoltage, or a combination thereof. .

-Support plate 16
The support plate 16 is a support plate having a recess in which the light emitting element 20 is mounted, and is a member on which a metal layer as a light reflection wall or a conductor wiring can be disposed. As shown in FIG. 3, the support plate 16 can be a package 16 in which a lead frame mainly made of aluminum or iron-containing copper is insert-molded in a resin. Further, instead of the package 16, a support plate 16 made of glass epoxy resin, ceramics, glass, or the like can be used. In particular, when the material of the support 16 is ceramic, a support having high heat resistance can be obtained.

  As the ceramic, alumina, aluminum nitride, mullite, silicon carbide, silicon nitride or the like is preferable. A plate-like support 16 can be obtained by laminating and firing ceramic green sheets obtained by molding a ceramic powder and a material obtained by mixing a binder resin into a sheet. Or it can be set as the support body which has a recessed part by forming and laminating | stacking through-hole of various magnitude | sizes in a ceramic green sheet. The first metal underlayer disposed on such a support was coated with a predetermined pattern of conductive paste containing fine particles of a refractory metal such as tungsten or molybdenum at the stage of an unfired ceramic green sheet. It can be obtained by firing. Furthermore, after firing the ceramic green sheet, nickel, gold, or silver can be plated in order on the pre-formed base layer to form a metal layer or conductor wiring disposed on the side surface of the recess.

  As described above, the support made of ceramic material can be formed by arranging the conductor wiring on a pre-fired ceramic plate in addition to integrally forming the conductor wiring and the insulating portion. . In the case of the support 16 made of ceramic, the ceramic base exposed on the side wall surface of the recess is preferably covered with a metal layer containing at least one metal selected from silver, aluminum, and rhodium. By using such a metal layer containing a highly reflective metal, light passing through porous ceramics is suppressed to improve light extraction efficiency from the light emitting device, and a light emitting device with higher brightness can be obtained. Can do. In particular, in the present invention, since the light reflected on the surface of the support plate 16 by the reflecting mirror 4 can be irradiated forward, the formation of the metal layer as described above is effective.

-Light emitting element 20
The light emitting element 20 can be a light source of a light emitting device, such as a light emitting diode chip or a laser diode chip. Examples of the semiconductor light-emitting element constituting the light-emitting diode chip include those using various semiconductors such as ZnSe and GaN. In the case of a light-emitting device having a fluorescent material, the fluorescent material can be excited efficiently. Preferred examples include nitride semiconductors capable of emitting short wavelengths (In _X Al _Y Ga _1-XY N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1). Various emission wavelengths can be selected depending on the material of the semiconductor layer and the degree of mixed crystal. For example, the LED chip can be a light emitting element that outputs not only visible light but also ultraviolet rays and infrared rays.

-Connecting conductor 24
The electrodes of the light emitting element 20 are preferably connected to lead electrodes 18a and 18b formed in the recess 16a of the support 16 by a connecting conductor 24 such as a wire. Further, a lead electrode may be formed outside the recess 16a. While the wire is easy to mount, there is a problem that a dark part is formed in the irradiated image by blocking a part of the light emitting surface. However, in the present invention, it is possible to prevent the shadow of the wire or the like from appearing in the irradiation image, so that the problem of deterioration of the irradiation image quality due to the use of the wire can be solved. Needless to say, the connecting conductor 24 may be a solder bump or a eutectic layer instead of a wire.

-Translucent member 22
The light emitting device 6 preferably further includes a light transmissive member 22 that covers the light emitting element 20. The material of the translucent member 22 can be selected from translucent resins such as epoxy resin and silicone resin, and translucent inorganic members such as glass. Moreover, the translucent member 22 can be formed by various molding methods such as compression molding, injection molding, or transfer molding using these as materials. By providing the translucent member 22, the conductive wire exposed outside the recess can be protected from the external environment by the translucent member, and a highly reliable light-emitting device can be obtained. In addition, since the translucent member has a convex shape in the light emission observation direction, the light emitted from the concave portion can be condensed and a light emitting device with high luminance can be obtained. Moreover, if the translucent member 22 is formed in a dome shape as will be described later, the light extraction efficiency can be further increased.

-Wavelength conversion member The wavelength conversion member is a member containing a fluorescent material that emits light having different wavelengths by absorbing at least part of the light from the light emitting element 20. Such a wavelength conversion member includes a fluorescent substance, a transparent resin such as an epoxy resin or a silicone resin, which is a binder for fixing the fluorescent substance, and a transparent inorganic member such as glass. It is preferable that the wavelength conversion member is filled and molded in the recess.

  The fluorescent substance converts light of the light emitting element, and it is more efficient to convert the light from the light emitting element 20 to a longer wavelength. In the case where the light from the light-emitting element is high-energy short-wavelength visible light, cerium-activated aluminum garnet (for example, YAG: Ce), which is a kind of aluminum oxide phosphor, is preferably used. In particular, the YAG: Ce phosphor absorbs part of the blue light from the LED chip depending on its content and emits yellow light that is a complementary color. Can be formed relatively easily. Note that the fluorescent material can be contained in a translucent member covering the conductive wire in addition to those contained in the wavelength conversion member.

Embodiment 2. FIG.
FIG. 11: is sectional drawing which shows the illuminating device which concerns on Embodiment 2 of this invention. In the present embodiment, a translucent dome-like member 23 is formed on the light emitting surface of the light emitting device 6 that is a light source. The other points are the same as in the first embodiment.

  FIG. 12 is a cross-sectional view schematically showing the light emitting device 6 used in the present embodiment. In the present embodiment, the surface of the sealing resin 22 that seals the light emitting diode chip 20 is processed into a substantially hemispherical shape to constitute a translucent dome-shaped member 23. The translucent dome-shaped member 23 may be formed by processing the sealing resin 22 itself that seals the light-emitting diode chip 20 into a dome shape. A dome made of a material may be fixed. Although the material which comprises the translucent dome-shaped member 23 will not be specifically limited if it is the material which permeate | transmits light emission of the light emitting diode 20, It is preferable that they are a silicone resin, an epoxy resin, etc.

  Also in the present embodiment, the focal positions of the lens 3 and the reflecting mirror 4 in the optical component 2 are set in the same manner as in the first embodiment. That is, as shown in FIG. 13, the focal point of the lens 3 formed on the bottom surface of the recess 2 c is shifted forward from the light emitting diode chip 20, while it is formed on the peripheral surface of the mountain-shaped protrusion 2 b of the optical component 2. The focal point of the reflected mirror 4 is on the light emitting diode chip 20. In this example, the focal point of the lens 3 is inside the translucent dome-shaped member 23. By placing the focal position inside the dome-shaped member 23, it can be brought close to the shape of the Kohler optical system, and ring-shaped unevenness can be suppressed.

  By forming the light-transmitting dome-shaped member 23, the light extraction efficiency of the light-emitting diode chip 20 can be increased, and the reduction in the light collection rate due to shifting the focus of the lens 3 from the light-emitting diode chip 20 can be compensated. That is, in the case of the light emitting device 6 as shown in FIG. 3 in which the dome-shaped member 23 is not formed, the light emitted from the light emitting diode chip 20 passes through the surface of the sealing resin 22 and is extracted outside. Since the surface of the sealing resin 22 is flat, a part of the light incident obliquely on the interface between the sealing resin 22 and the air from the light emitting diode chip 20 is reflected and returns to the inside of the lamp 6. In particular, the portion where the incident angle (the angle formed by the interface normal and the incident light ray) exceeds the critical angle is totally reflected and returns to the lamp 6. The light returning to the lamp 6 is absorbed and attenuated by the chip 20 and the sealing resin 22 while being repeatedly reflected in the lamp 6. On the other hand, as shown in FIG. 12, when the dome-shaped member 23 is formed on the surface of the lamp 6, the incident angle at which the light emitted from the light-emitting diode chip 20 enters the interface between the dome-shaped member 23 and the air is small. Therefore, the ratio of returning to the inside of the lamp 6 due to reflection decreases. For this reason, the light extraction rate of the light emitting diode chip 20 can be improved. As described in the first embodiment, when the focal position of the lens 3 is shifted from the light source to the near side, the light collection rate by the lens 3 itself decreases, but by forming a dome-shaped member on the light emitting surface of the light source, the lens 3 is compensated for, and an irradiation image excellent in emission intensity and uniformity can be obtained.

  It is also preferable to disperse an appropriate diffusing material in the translucent dome 23. Thereby, the problem that the luminance distribution of the light emitting diode chip 20 appears in the irradiation image can be more effectively suppressed. As the diffusion material, for example, barium titanate, titanium oxide, aluminum oxide, silicon oxide, silicon dioxide, calcium carbonate, and a mixture thereof can be used.

  From the viewpoint of the light extraction efficiency of the light emitting diode chip 20, the light extraction diode 23 has a hemispherical surface, and the light extraction diode chip 20 is located at the center of the sphere so that the extraction efficiency is highest. That is, the angle at which the light emitted from the light emitting diode chip 20 is incident on the interface between the dome-shaped member 23 and the air is always 0 °, so that theoretically there is no component that returns to the inside of the lamp 6 due to reflection.

  On the other hand, the translucent dome-shaped member 23 may have a desired lens effect. For example, when the surface of the translucent dome-shaped member 23 is substantially spherical, the position shifted from the center of the sphere (or the center of the sphere when the surface of the dome-shaped member 23 is approximated to a spherical surface), for example, the translucent dome 23 is If the light-emitting diode chip 20 is arranged at a position corresponding to the paraxial focal point of the spherical lens to be formed or before and after the position, the lens effect by the translucent dome-shaped member 23 can be obtained. Further, the surface shape of the translucent dome-shaped member 23 may be an aspherical surface capable of obtaining a desired lens effect. Even when the translucent dome 23 has some lens effect, the effect of increasing the light extraction efficiency is not lost compared to the case where the surface of the sealing resin 22 is flat.

  Further, since the translucent dome-shaped member 23 has a lens effect, the image of the light-emitting diode chip 20 is further hardly projected on the irradiation object. That is, by giving the dome-shaped member 23 a lens effect and reducing the amount of light taken into the lens 3, the spot image by the lens 3 can be relaxed. Further, by increasing the amount of light to the reflecting mirror 4, the light collection rate can be improved, and the light distribution characteristic having a peak characteristic in the vicinity of ± 60 ° from the Lambertian light distribution characteristic is also possible. For example, FIG. 15 is a graph showing the illuminance distribution on the screen when the light-emitting diode chip 20 is disposed between the spherical center of the hemispherical dome-shaped member 23 and the paraxial focus. The meanings of the symbols in FIG. 15 are the same as those in FIG.

  FIGS. 14A to 14C show irradiation images on the screen when the dome-shaped member 23 having the same conditions as in FIG. 15 is used. 14A to 14C in the present embodiment are compared with FIGS. 6A to 6C in the first embodiment, the image formed by the reflecting mirror 4 (FIGS. 6A and 14A) is not significantly changed, but the image formed by the lens 3 (FIG. 6B). 14B) shows that the isotropic property is improved. That is, in the spot image of the lens 3 according to Embodiment 1 shown in FIG. 6B, there is an illuminance distribution that repeats every 90 ° in the rotation direction, but in the spot image of the lens 3 shown in FIG. Is not seen, and the spot image is almost isotropic.

  Thus, if the translucent dome-shaped member 23 has a lens effect, an effect that the pattern of the light source is more difficult to be projected onto the irradiated object can be obtained.

  For the optical component 2 shown in FIG. 5, a simulation was performed on an image formed by the lens 3, an image formed by the reflecting mirror 4, and a composite image thereof on a screen 1 m away from the optical component 2. More specifically, the simulation was performed under the following conditions.

  First, the refractive index of the optical component 2 was 1.49. The lens 3 was a free-form surface (aspherical) lens having a diameter of 5 mm and a focal length of about 3 mm, and the focal point was set at a position of about 1 mm in front of the chip. On the other hand, the reflecting mirror 4 is a free-form surface (aspherical shape) having an effective lens diameter of 15 mm and a focal point on the light-emitting diode chip 20. The recess 2c has a depth (depth to the tip of the lens 3) of 2 mm. The light emitting device 6 contains a blue light emitting diode chip 20 having a square whose upper surface is approximately 600 μm on a side, and a fluorescent material that emits yellow light by absorbing at least part of the light from the blue light emitting diode chip 20. A wavelength conversion member, and emits white light. In order to simplify the calculation, the luminance distribution in the upper surface of the light emitting diode chip 20 is uniform.

  As a result, the illuminance distribution as shown in FIGS. As shown in FIG. 6C, an isotropic irradiation image in which the shape of the light-emitting diode chip 20 was not projected was obtained.

[Comparative Example 1]
For the optical component 2 ′ shown in FIG. 8, a simulation was performed on an image formed by the lens 3 ′, an image formed by the reflecting mirror 4 ′, and a composite image thereof on a screen 1 m away from the optical component 2 ′. The simulation was performed in the same manner as in Example 1 except that the focal position of the lens 3 ′ was matched with the surface of the light emitting diode chip 20.

  As a result, illuminance distributions as shown in FIGS. 9A to 9C and FIG. 10 were obtained. As shown in FIG. 9C, the rectangular shape of the light emitting diode chip 20 appeared strongly in the irradiation image on the screen.

  For the optical component 2 shown in FIG. 13, a simulation was performed on an image formed by the lens 3, an image formed by the reflecting mirror 4, and a composite image thereof on a screen 1 m away from the optical component 2. The simulation was performed in the same manner as in Example 1 except that the translucent dome 23 was disposed on the light emitting surface of the light emitting diode chip 20.

  Specifically, the refractive index of the translucent dome 23 is 1.41, the diameter is about φ3 mm, the surface shape is a spherical surface having a radius of about 1.3 mm, and the position of the light emitting diode 20 is adjusted to the lowermost end of the optical component 2. .

  As a result, the illuminance distribution as shown in FIGS. As shown in FIG. 14C, a more isotropic irradiation image than that in Example 1 was obtained. Compared with Example 1, the central illuminance was improved by 1.13 times, and the overall light emission extraction efficiency was improved by 1.85 times.

FIG. 1A is a perspective view showing an example of a lighting device of the present invention. FIG. 1B is a schematic cross-sectional view showing a B-B ′ cross section of the illumination device shown in FIG. 1A. 2 is an exploded perspective view of the lighting device shown in FIG. 1A. FIG. 3 is a schematic cross-sectional view illustrating an example of a light emitting device. FIG. 4 is a cross-sectional view showing an example of an optical component. FIG. 5 is a schematic diagram showing the relationship between the optical component and the light-emitting diode chip in the first embodiment. FIG. 6A is a schematic diagram showing an image formed by the reflecting mirror of the optical component shown in FIG. FIG. 6B is a schematic diagram showing an image formed by the lens of the optical component shown in FIG. FIG. 6C is a schematic diagram showing an image formed by the optical component shown in FIG. FIG. 7 is a graph showing the illuminance distribution of the image formed by the reflecting mirror, lens, and optical component of the optical component shown in FIG. FIG. 8 is a schematic diagram showing the relationship between the optical component and the light-emitting diode chip in the comparative embodiment. FIG. 9A is a schematic diagram showing an image formed by the reflecting mirror of the optical component shown in FIG. FIG. 9B is a schematic diagram showing an image formed by the lens of the optical component shown in FIG. FIG. 9C is a schematic diagram showing an image formed by the optical component shown in FIG. FIG. 10 is a graph showing the illuminance distribution of an image formed by the reflecting mirror, lens, and optical component of the optical component shown in FIG. FIG. 11 is a schematic cross-sectional view showing the lighting apparatus in the second embodiment. FIG. 12 is a schematic cross-sectional view illustrating another example of the light emitting device. FIG. 13 is a schematic diagram showing the relationship between the optical component and the light-emitting diode chip in the second embodiment. FIG. 14A is a schematic diagram showing an image formed by the reflecting mirror of the optical component shown in FIG. FIG. 14B is a schematic diagram showing an image formed by the lens of the optical component shown in FIG. FIG. 14C is a schematic diagram showing an image formed by the optical component shown in FIG. FIG. 15 is a graph showing the illuminance distribution of the image formed by the reflecting mirror, lens, and optical component of the optical component shown in FIG. FIG. 16A is a schematic cross-sectional view illustrating an example of a conventional lighting device. FIG. 16B is a schematic cross-sectional view illustrating another example of a conventional lighting device. FIG. 17 is a plan view showing an example of a light emitting diode chip. FIG. 18 is a schematic diagram showing a spot image when a screen is projected by a conventional illumination device.

Explanation of symbols

1 lighting device,
2 optical components,
3 lenses,
4 Reflector,
5 holder,
6 Light emitting device,
7 Collimating lens,
8 Light emitting unit,
9 substrate,
10 Heat dissipation plate,
12 Fixing member (screw),
20 Light emitting diode chip

Claims (4)

An optical component that includes a lens and a rotating curved reflecting mirror, and condenses light emitted from a light source disposed behind the lens by the lens and the reflecting mirror and emits the light forward; and a light emitting surface as the light source A light emitting diode chip having an electrode pattern on the lighting device,
The lens is a collimating lens that collimates light emitted from a point light source at its focal point,
The reflecting mirror makes the light emitted from the point light source at the focal point parallel light,
The lens and the reflecting mirror are integrally formed of glass or resin,
The illumination device characterized in that the focal point of the lens is shifted forward from the light emitting diode chip, and the focal point of the reflecting mirror is on the light emitting diode chip.   The optical component has a protrusion that protrudes rearward and has a protrusion in which the light emitting diode chip is to be disposed at the protrusion, the lens is formed on the bottom surface of the recess, and the reflector is the protrusion. The lighting device according to claim 1, wherein the lighting device is formed on a peripheral surface of the lighting device. The illumination device according to claim 1, wherein a reflection film is formed on a surface of the reflection mirror.   The illuminating device according to claim 1, wherein a translucent dome member formed on the light emitting diode chip is formed.

Images