JP2012169507A - Led light-emitting device and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration of an appearance of an LED light-emitting device (1) and a mobile phone (100) mounted with the same, when the LED light-emitting portion is looked from the outside, by making coloring of a fluorescent body containing portion (12) inside hard to be observed.SOLUTION: A lens (20) is provided on a front surface of an LED light-emitting portion (10). A large number of corner cube prisms (30) are provided on a light incident surface (21) opposed to the LED light-emitting portion (10) of the lens (20). When looking the LED light-emitting portion (10) from an emitting surface (25) of the lens (20) through the lens (20), a fluorescent body containing portion (12) is reflected by the corner cube prisms (30) and becomes hard to be observed. On the other hand, light emitted from the LED light-emitting portion (10) is incident from the corner cube prisms (30), and emitted from the emitting surface (25) to illuminate.

Description

  The present invention relates to a light-emitting device using a light-emitting element such as a light-emitting diode (hereinafter referred to as LED) as a light-emitting source. The present invention relates to a light emitting device mounted for illumination.

  Conventionally, a photographing device such as a compact camera is provided with a light emitting device such as a strobe. In recent years, LEDs have been used for camera lighting and strobe light sources of mobile phones. A light emitting device in which this LED is mounted as a light emitting element is disclosed in Patent Document 1, for example.

  10 and 11 show a light emitting device described in Patent Document 1. FIG. The light emitting device 100 of Patent Document 1 includes a substrate 200, an LED chip 300 disposed on the substrate 200, a lens holding unit 600 in which a reflector 400 is integrally formed, and a lens 500.

  As shown in FIG. 11, the LED chip 300 includes a second LED package 370 having a concave reflecting mirror 380, a circuit board 310 provided on the concave reflecting mirror, and a surface of the circuit board 310 on the irradiation direction side. It has a blue light emitting element 320 and a first LED package 350 mounted on the (upper side), and a red light emitting element 330 mounted on the back side (lower side) of the circuit board and facing the concave reflecting mirror. The blue light emitting element 320 is covered with a phosphor coating region 360 containing a YAG phosphor. The circuit board is provided with an opening 390, and light emitted from the red light emitting element 330 is reflected by the concave reflecting mirror 380 and guided from the opening 390 to the blue light emitting element side. As a result, the light emitted from the blue light-emitting element and the light emitted from the phosphor-coated region that absorbs the blue light-emitting element and emits yellow light are mixed with white light, and the light from the red light-emitting element is further mixed. Can be irradiated. It is described that the color temperature and the color unevenness of the entire irradiated surface are improved by irradiating the irradiated surface with bluish red light.

JP 2010-192582 A

  However, although the color unevenness of the irradiated surface by the white light obtained by the color mixture of the light emitted from the blue light emitting element and the light from the phosphor coating region is improved, the above LED light emitting device looks yellow due to the ambient light. . This yellow color is the phosphor color in the phosphor coating area. Depending on the design of the main body case of the digital camera or mobile phone, the color of the main body case and the yellow color (phosphor color) of the LED light-emitting device may be mismatched. , Appearance is unsatisfactory and may detract from aesthetics.

  The present invention solves the above-described conventional problems. In an LED light-emitting device capable of emitting white light in which a phosphor is contained in a sealing resin portion, the appearance of the LED light-emitting device as a whole is impaired by the coloring of the sealing resin portion. It is an object of the present invention to provide an LED light emitting device that is not used and an electronic device in which the light emitting device is mounted for camera illumination.

In order to achieve the above object, an LED light-emitting device of the present invention includes a substrate (13) having the following main features:
An LED light emitting section (10) disposed on the substrate (13);
A resin lens (20) disposed on the LED light emitting unit (10);
An air layer (16) between the LED light emitting unit (10) and the lens (20) and in contact with the lens (20);
The LED light emitting part (10) is formed with a sealing resin part (12) to which a phosphor is added,
The lens includes a light incident surface (21) having a projected area larger than the projected area of the LED light emitting unit upper surface (14) at a position facing the upper surface (14) of the LED light emitting unit (10). Having an inclined surface (23) continuous to the optical surface (21);
The light incident surface (21) has an uneven surface of a corner cube array (22),
The inclined surface (23) includes a reflective surface (24) having a tangent line that intersects an acute angle with a plane passing through the light emission central axis of the LED light emitting unit (10).

  According to the above-described invention, it is possible to provide an LED light-emitting device that irradiates the irradiation light from the LED light-emitting portion, makes it difficult to observe the sealing resin from the outside, and does not impair the beauty by coloring the sealing resin portion. The effect that it can be obtained.

Further, in the LED light emitting device (1), the corner cube array (22) includes a corner cube prism (30) having three surfaces and two surfaces forming a right angle with each other.
The reflecting surface (24) of the lens (20) is in contact with the air layer and is a curved surface connecting a plurality of ellipsoidal systems.

  According to the present invention, a part of light incident from any surface of the aligned corner cube prism can be re-reflected in a desired direction by the reflecting surface, and the utilization efficiency of the light emitted from the LED light emitting unit There is an advantage that can be increased.

  The illuminated electronic device of the present invention is an electronic device (100) equipped with any of the LED light emitting devices (1) described above, and faces the light incident surface (21) to the lens (20). The electronic device (100) includes a flat emission surface (25), and includes an opening (104), and the lens (20) is fitted in the opening (104).

  According to the present invention, even when the LED light emitting device is observed from the outside, the sealing resin is hardly observed through the lens, and the aesthetic appearance of the entire electronic device is not impaired by the coloring of the sealing resin portion. There is an advantage that equipment can be provided.

  ADVANTAGE OF THE INVENTION According to this invention, while irradiating the irradiation light from a LED light emission part, the effect that it is hard to observe sealing resin from the outside is acquired.

FIG. 1 is a schematic front view and rear view of a mobile phone showing an example of an electronic apparatus provided with the LED light emitting device of the first embodiment. FIG. 2 is a schematic perspective view showing camera illumination using the LED light emitting device of FIG. FIG. 3 is a schematic cross-sectional view showing a state where an LED light emitting device is attached to the mobile phone of FIG. FIG. 4 is a schematic cross-sectional view illustrating the LED light emitting device of FIG. FIG. 5 is a schematic perspective view of a part of the corner cube array as seen from the surface-mounted LED side. FIG. 6 is a schematic perspective view illustrating an enlarged corner cube prism. FIG. 7 is an explanatory diagram showing an optical path when a simulation is performed on a light beam emitted from a surface-mounted LED. FIG. 8 is a diagram showing a light distribution pattern showing the directivity characteristics of the surface-mounted LED used for the simulation. FIG. 9 is a schematic cross-sectional view showing an LED light-emitting device according to another embodiment. It is explanatory drawing of the conventional light-emitting device, (a) is a schematic front view, (b) is a schematic sectional drawing. It is explanatory drawing of the conventional LED, (a) is a schematic front view, (b) is a schematic sectional drawing.

  Hereinafter, the lamp which is one Embodiment of this invention is demonstrated, referring FIGS.

  FIG. 1 is a schematic front view and a rear view of a mobile phone showing an example of an electronic device provided with the LED light emitting device of the present invention, and FIG. 2 is a schematic perspective view showing camera illumination using the LED light emitting device of FIG. FIG. 3 is a schematic cross-sectional view showing a state where an LED light emitting device is attached to the mobile phone of FIG.

  The LED light-emitting device 1 according to the present invention is used as camera illumination 101 that is used, for example, when photographing using the camera 102 of the mobile phone 100. As shown in FIG. 1, the mobile phone 100 includes a display unit made up of a liquid crystal display device and the like on the front side and operation button units such as numeric keys, and a camera 102 and camera illumination 101 on the back side. The camera illumination 101 is provided in a landscape orientation around the camera lens, particularly obliquely above the camera 102 lens.

  As shown in FIGS. 2 and 3, the camera illumination 101 includes an LED light-emitting device 10 including a lens 20 formed of a transparent resin material and the LED light-emitting device as a strobe light source for instantaneous lighting and / or continuous illumination as a light source. The lighting control circuit 40 is turned on. The lighting control circuit 40 is provided close to the back surface of the mounting substrate 13 of the LED light emitting device 10.

  FIG. 4 is a schematic cross-sectional view illustrating the LED light emitting device 1.

  The LED light emitting device 1 includes a mounting board 13 provided with wiring electrodes (not shown), a surface-mounted LED 10 mounted on the mounting board 13 and connected to the wiring electrodes (not shown), and a lens 20 attached and fixed to the mounting board 13. Thus, the surface-mounted LED 10 is located in the light source chamber 15 formed between the lens 20 and the mounting substrate 13. In the present embodiment, a corner cube array 22 described later is provided on the incident surface 21 of the lens 20 facing the surface-mounted LED 10. The LED light emitting device 1 is fitted in the case opening 104 of the main body case 103 of the mobile phone 100.

  The mounting board 13 has a rectangular shape, and a printed board using glass epoxy resin or the like, a metal board in which a metal board is covered with an insulating layer, a ceramic board, or the like is used. The surface of the mounting board 13 is plated with metal wiring. A wiring electrode (not shown) is formed by a known method such as provision. One end of the wiring electrode is electrically connected to the surface-mounted LED 10 using solder or the like, and the other end is formed to the outside of the LED light emitting device 1 and is electrically connected to the lighting control circuit 40. ing.

  The surface-mounted LED 10 is mounted at the center of the mounting substrate 13, and an insulating colored insulating film 13 a is applied to the peripheral portion of the mounting substrate. The colored insulating film 13 a reflects stray light leaking into the light source chamber 15. In addition, when the observer observes the LED light emitting device 1, it is colored in a color that does not cause a design mismatch with the coloring of the main body case 103. The colored insulating film 13a is preferably white and is a diffuse reflection film mixed with glass beads or the like. By providing the white diffuse reflection film 13a, the stray light can be extracted outside the LED light emitting device 1 through the lens 20. The stray light means that the irradiation light from the surface mounting LED 10 is incident on the lens 20, and a part of the light is reflected from the surface of the lens 20 or reflected from the inner surface of the lens 20 without being irradiated from the lens exit surface 25. A component of light reflected and / or refracted toward the LED 10, for example, light such as L4 shown in FIG. In the present embodiment, since the corner cube array 22 is formed, in the case of an irradiation angle from the surface mount LED 10, for example, an irradiation angle when going from the left end to the right end of the corner cube array 22, a part of Light tends to become stray light. Therefore, by providing the white diffuse reflection film 13a, it is possible to further extract and use these lights. In place of the white diffuse reflection film 13a, the metal surface of the substrate metal when a metal substrate is used or the ceramic substrate surface when a white ceramic substrate is used can be used as the reflection film.

  The surface-mount LED 10 is a surface-mount type LED having a phosphor-containing portion 12 on the surface, and the fluorescence included in the phosphor coating portion 12 such as a blue light emitting diode (not shown) between the phosphor-containing portion 12 and the mounting substrate. A semiconductor light emitting device that emits light having a wavelength for exciting the body is provided. In the present embodiment, a dome-shaped phosphor-containing portion 12 is formed on the surface. The phosphor-containing portion 12 is formed by a method such as coating, molding, or potting using a dispenser on a surface by dispersing colored phosphor particles such as YAG phosphor in a transparent resin material such as silicone resin. . The surface-mounted LED 10 is not limited to providing the phosphor-containing portion 12 on the outermost surface. For example, the LED 300 described in Patent Document 1 described above can be used as the surface mount LED, and the phosphor-containing portion 12 may be covered with a transparent resin layer.

  The lens 20 is made of a translucent resin material having a high transmittance such as acrylic or polycarbonate, and is formed by, for example, injection molding. The lens 20 has a box shape having a rectangular shape when viewed from the front, and fixed legs 27 on the peripheral side surface are fixedly attached to the mounting substrate 13. A step portion 26 is formed on the surface side of the lens 20, and the main body case 103 is attached in a state where the step portion 26 and the upper emission surface 25 are fitted in the case opening 104.

  A light incident surface 21 and an inclined surface 23 provided with a corner cube array 22 are formed on the opposite side of the emission surface 25, that is, on the lens inner surface side, and the light incident surface 21 faces the surface-mounted LED 10. The corner cube array 22 is located on a virtual plane orthogonal to the light emission center axis CL of the surface-mounted LED 10 facing the light incident surface 21. In the present embodiment, an example in which one surface-mounted LED 10 is provided in one LED light-emitting device will be described. The light-emitting central axis CL of the surface-mounted LED 10 and the central axis of the surface-mounted LED 10 are the same. When a plurality of surface-mounted LEDs are arranged in one LED light-emitting device, the central axis CL of the plurality of surface-mounted LEDs exists. In the present embodiment, the light emission center axis CL of the surface-mounted LED 10 facing the light incident surface 21 is the center axis of the light distribution pattern of the LED light emitting device 1.

  The light source chamber 15 is filled with air. An air layer 16 exists between the light incident surface 21 and the surface-mounted LED 10, and the air layer 16 is in contact with the surface of the corner cube array 22 and the output surface of the surface-mounted LED 10.

  FIG. 5 is a schematic perspective view of a part of the corner cube array 22 as viewed from the surface-mounted LED 10 side, and FIG. 6 is a schematic perspective view illustrating an enlarged corner cube prism. The corner cube array 22 includes corner cube prisms 30 arranged in a matrix as shown in FIG. In FIG. 5, only one corner cube prism 30 is provided with a reference numeral, and reference numerals 22 a, 22 b, and 22 c are attached to straight lines passing through the bottom side of the corner cube prism 30, i.e., a side that is a valley. The straight lines 22a, 22b and 22c indicating the valleys intersect at an intersection angle of 60 degrees. The vertex 30d of the corner cube prism 30 protrudes toward the surface-mounted LED 10 with respect to the straight lines 22a, 22b, and 22c.

  FIG. 6 is a schematic perspective view for explaining an example of a retroreflective optical path for the corner cube prism 30 of FIG. The vertex on the left side of the drawing is a portion protruding to the surface-mounted LED 10 side. The corner cube prism 30 has a triangular pyramid shape with a base of an equilateral triangle formed by the straight lines 22a, 22b, and 22c. Three surfaces centering on the apex angle forming the triangular pyramid are orthogonal to the adjacent prism surfaces. That is, the first prism surface 31 is orthogonal to the respective planes of the second prism surface 32 and the third prism surface 33. The second prism surface 32 is orthogonal to the planes of the first prism surface 31 and the third prism surface 33. The third prism surface 33 is orthogonal to the planes of the first prism surface 31 and the second prism surface 32. That is, it corresponds to a rectangular parallelepiped corner centered on the vertex 30d. Further, all the prism surfaces 31, 32, and 33 of the corner cube prism 30 are in contact with the air layer 16 between the surface mount LED 10.

  For example, when the external light O shown in FIG. 4 enters the lens 20, the external light O travels through the lens 20 toward the corner cube array 22. External light O travels toward the first prism surface 31 through an equilateral triangle composed of straight lines 22a, 22b and 22c. After being internally reflected by the first prism surface 31, it is reflected toward the second prism surface 32. After the second internal reflection at the second prism surface 32, the light is reflected toward the third prism surface 33. Next, after third internal reflection at the third prism surface 33, the light travels in the same direction as the external light O when it is incident, and is emitted to the outside from the emission surface 25 of the lens 20. A central axis passing through each vertex of the corner cube prism 30 is parallel to the light emission central axis CL.

  Therefore, when the LED light-emitting device 1 is observed from the outside, that is, when viewed from directly above the emission surface 25, the surface-mounted LED 10 cannot be seen due to the retroreflective characteristics of the corner cube prism. Even when observed from an oblique direction, the surface-mounted LED 10 becomes difficult to see due to the retroreflective characteristics of the corner cube prism. That is, the coloring of the phosphor-containing portion 12 is hardly observed.

  The surface-mounted LED 10 generally has directivity unlike a light bulb (see FIG. 8). Therefore, in the present embodiment, the light incident surface 21 is in the vicinity of the surface-mounted LED emitting surface 14 and can capture light spreading from the surface-mounted LED emitting surface 14. Specifically, the projected area of the light incident surface 21 on which the corner cube array 22 is formed is larger than that of the surface-mounted LED emitting surface 14. In this embodiment, the corner cube array 22 is formed on the entire light incident surface 21.

  The inclined surface 23 is a free-form surface that is formed continuously with the light incident surface 21 and approximates a rotating paraboloid with the light emission center axis CL as the center of rotation. A reflecting surface 24 is formed on the inclined surface 23. In the reflecting surface 24, light emitted from the center point of the surface-mounted LED 10 enters the corner cube prism 30, and light incident from any one of the prism surfaces 31, 32, and 33 passes through the lens 20, The reflecting surface is formed at a position reaching the inclined surface 23 and uses a difference in refractive index between the air filling the light source chamber 15 and the resin material constituting the inclined surface 23. When a light beam incident on the reflection surface 24 exceeds the critical angle, it is reflected at the interface with the light source chamber 15 and reflected in a predetermined direction.

  The reflecting surface 24 is designed as a composite reflecting surface that is finely divided. The reflecting surface 24 forms the inclined surface 23 as a free-form surface composed of a curve obtained by approximating the composite reflecting surface with a known curve such as a spline curve in consideration of mold processing for molding the lens 20 and molding accuracy and cost. To do. The tangent line of the inclined surface 23 intersects with a plane passing through the light emission center axis CL, and the inclination angle is an acute angle. Therefore, the inclined surface 23 forms a dome shape.

  Next, the irradiation light when the surface-mounted LED 10 is turned on will be considered.

  A light beam L1 and a light beam L2 indicated by dotted lines in FIG. 4 indicate a schematic optical path in which light emitted from the surface-mounted LED 10 is reflected by the reflecting surface 24 after entering the corner cube prism 30. FIG. 7 is an explanatory diagram showing an optical path when a part of the light emitted from the surface mount LED 10 is simulated with respect to a light beam traveling toward the corner cube array 22 through the air layer 16. In the simulation of FIG. 7, the emission surface 25 of the surface-mounted LED is simulated as a flat surface, and rays emitted from the emission surface 25 are shown by straight lines. FIG. 8 is a light distribution pattern showing the directivity characteristics of the surface-mounted LED 10 used for the simulation.

  As can be seen from FIGS. 7 and 8, almost all of the light emitted from the surface-mounted LED travels from the light incident surface 21 into the lens 20. The light enters the lens 20 from any one of the prism surfaces 31, 32, and 33 of the corner cube prism 30. Part of the light that has entered the lens 20 proceeds directly toward the exit surface 25, and part of the light travels toward the inclined surface 23. A part of the light directed toward the inclined surface 23 is internally reflected by the reflecting surface 24 like the light rays L1 and L2, and then proceeds toward the emitting surface 25, and a part thereof from the inclined surface 23 like the light rays L3 and L5. 15 is emitted toward the inside. Further, part of the light emitted from the surface-mounted LED 10 proceeds toward the light source chamber 15 without entering the lens 20 like the light beams L4 and L6. As shown in FIG. 7, most of the light beams emitted from the surface mount LED 10 are emitted from the emission surface 25. Light rays L3, L4, L5, and L6 that are directed into the light source chamber 15 are stray light that is reflected by the white coating 13a of the mounting substrate 13 and then enters the lens 20, and a part of the light is emitted from the light exit surface 25. Exit.

  As described above, when the LED light-emitting device 1 is observed from the external front direction through the emission surface 25 as shown in FIG. 3, the phosphor-containing portion 11 of the surface-mounted LED 10 is formed by the retroreflective characteristics in the corner cube array 22. Not observed. When the observation direction is oblique from the front, depending on the set angle of the apex angle of the corner cube prism 30, an angle at which a part of the phosphor-containing portion 11 is observed may be generated. The part 11 is hardly observed or hardly observed. On the other hand, when the surface-mounted LED 10 is turned on, the prism surfaces 31, 32, and 33 function as incident surfaces. A desired light distribution can be obtained by optimizing the shapes of the prism surfaces 31, 32, 33 and the reflecting surface 24. Also, a prism element can be provided on the exit surface 25.

  As a result, according to the LED light-emitting device of the present invention, an effect that the phosphor-containing portion 11 can be hardly observed from the outside can be obtained.

  The above embodiment is merely an example in all respects. The present invention is not construed as being limited to these descriptions. For example, as shown in FIG. 9, a part of the lens 20, for example, the corner cube array 22, may be created separately and attached, or may be made of an ultraviolet curable resin. By using the ultraviolet curable resin layer 50, the shape of the corner cube array 22 can be transferred using a stamper without using a fine mold. Further, the lens 20 having a shape with the fixed leg 27 as a separate body is also included in the present invention.

  The light-emitting device according to the present invention is a light-emitting device using a light-emitting element such as a light-emitting diode (hereinafter referred to as LED) as a light-emitting source. It can also be applied to applications such as a light emitting device mounted for camera illumination of a small photographic device mounted on an electronic device such as a television phone camera.

1 LED light emitting device 10 Surface mounted LED
DESCRIPTION OF SYMBOLS 11 Sealing resin part 12 Phosphor content part 13 Mounting board 14 Surface mounting LED light emission surface 15 Light source chamber 16 Air layer 20 Lens 21 Light incident surface 22 Corner cube array 23 Inclined surface 24 Reflective surface 25 Output surface 26 Stepped part 27 Fixed leg 30 corner cube prism 31 first prism surface 32 second prism surface 33 third prism surface 40 lighting control circuit 50 ultraviolet curable resin layer 100 electronic device (mobile phone)
101 Camera illumination 102 Camera 103 Main body case 104 Case opening

Claims (3)

A substrate,
An LED light emitting unit disposed on the substrate;
A resin lens disposed on the LED light emitting unit;
An air layer between the LED light emitting unit and the lens and in contact with the lens,
The LED light emitting part is formed with a sealing resin part added with a phosphor,
The lens has a light incident surface having a projection area larger than the projection area of the LED light emitting unit upper surface at a position facing the upper surface of the LED light emitting unit, and an inclined surface continuous to the light incident surface,
The light incident surface has an uneven surface of a corner cube array,
The LED light emitting device, wherein the inclined surface includes a reflective surface having a tangent line that intersects an acute angle with a plane passing through the light emission central axis of the LED light emitting unit. The LED light-emitting device according to claim 1,
In the LED light-emitting device, the corner cube array has three cubes arranged in a corner cube prism with two surfaces forming a right angle.
The LED light-emitting device, wherein the reflecting surface of the lens is a curved surface in contact with an air layer and connecting a plurality of ellipsoidal systems. An electronic device equipped with the LED light-emitting device according to claim 1 or 2,
The lens has a flat emission surface facing the light incident surface,
The electronic device includes an opening, and the lens is fitted in the opening.

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