JP2017098044A - Led light bulb for headlamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED light bulb for headlamp capable of enhancing luminous intensity by utilizing light for low beam effectively, capable of expanding a light emission range and capable of solving the problem of color unevenness (color separation) by a false light emission color.SOLUTION: An LED light bulb 1 for headlamp which is mounted on a vehicular headlamp capable of switching light distribution between high beam and low beam includes: an LED 4 for high beam and an LED 5 for low beam mounted on a substrate 3; and a shade 6 for shielding one part of the light emitting from the LED 5 for low beam. Retroreflection beads 7 are coated on the entire inner surface of the shade 6. Also, the substrate 3, and the LED 4 for high beam and the LED 5 for low beam mounted on this, and the shade 6 are made as one set and arranged on both left and right sides. Furthermore, a blue fluorescent dye is coated at least on a portion of the shade 6 at which yellow light radiates.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an interchangeable LED bulb used as a light source of a vehicle headlamp that can switch light distribution between a high beam and a low beam with a single lamp.

  Conventionally, halogen light bulbs or the like are used as light sources of headlamps arranged on the left and right of the front part of the vehicle. In this type of light bulb, a filament that is a light emitting part is held by an inner lead in a glass tube 360. Emits light in all directions.

  By the way, the switchable bulb used in the two-lamp headlamp has a function that can switch the light distribution between high beam (running beam) and low beam (passing beam), and it is an oncoming vehicle or pedestrian at night. If there is a possibility of giving glare to the light, the light distribution is switched to a low beam. In this way, when the light distribution is switched to the low beam, the light emitted from the filament of the bulb is controlled by a shade that is a metal light-shielding object. Specifically, the light emitted downward from the filament of the bulb is reflected upward by the shade, and the reflected light is reflected downward by the upper reflecting surface of the reflector provided in the headlamp. Only the underside of the road is illuminated and there is no glare for oncoming vehicles and pedestrians at night.

  Thus, the various light bulbs attached to the headlamps of new domestic vehicles satisfy the European ECE standard (No. 37), and the ECE standard defines the shape and dimensions of the shade in detail. Yes. Therefore, the bulbs designed and produced based on the ECE standard have the same performance, specifications and the like regardless of the manufacturer, and the same applies to the bulbs for repair sold as replacements in the market.

  By the way, in recent years, LED bulbs using LEDs (light-emitting diodes) having high luminous efficiency, long life and power saving as light-emitting parts are being used, and these LED bulbs are purchased for replacement by general users. To do. Many LED bulbs used as light sources for headlamps obtain a pseudo luminescent color with a blue LED and a phosphor for white light emission. It is to be noted that proposals have been made for Patent Document 1 regarding LED light emitting elements and Patent Document 2 for optical elements and illumination devices.

  Since LED bulbs for replacement need not satisfy the ECE standard, there is no unified standard. Therefore, the LED bulbs are unique to each company, including the appearance design, all the parts, and the shade shape.

JP 2009-294652 A WO2014 / 103696A1

  In high beam / low beam switching type LED bulbs such as H4, the inner surface (reflective surface) of the shade for blocking the lower light when the light distribution is switched to the low beam is subjected to a reflection treatment such as plating. Since not all of the downward light is correctly reflected in the intended direction, the light is not effectively used for low beam, and there is a problem of generation of glare light and reduction of low beam intensity.

  Accordingly, an object of the present invention is to provide an LED bulb for a headlamp that can effectively use low-beam light and increase its luminous intensity.

  In addition, since the LED is mounted on a substrate that does not transmit light, such as a rigid substrate or a metal base substrate, there is a problem that light does not reach the opposite side of the light emitting surface and the light emission range is narrow.

  Accordingly, an object of the present invention is to provide an LED bulb for a headlamp that can widen the light emission range.

  Furthermore, in LED bulbs, a phenomenon called yellow ring occurs in which color-separated yellow light is irradiated in a ring shape, or light other than white such as blue is mixed, so white is defined by chromaticity. Headlamps may cause security standard problems.

  Accordingly, an object of the present invention is to provide an LED bulb for a headlamp that solves the problem of color unevenness (color separation) due to pseudo emission color.

  In order to achieve the above object, according to the first aspect of the present invention, a high beam LED and a low beam LED mounted on a substrate mounted on a vehicle headlamp capable of switching light distribution between a high beam and a low beam, and the low beam An LED bulb for a headlamp comprising: a shade that blocks a part of light emitted from an LED; and a reflector that reflects light emitted from the LED in a lamp optical axis direction. The shade is provided on the substrate. The LED is positioned between the LED and the reflector in the left-right direction, and the optical axis of the LED is perpendicular to the lamp optical axis direction, and the entire inner surface of the shade is retroreflective beads. It is characterized by having applied.

  A second aspect of the invention is characterized in that, in the first aspect of the invention, a blue fluorescent dye is applied to at least a portion of the shade that is exposed to yellow light.

  According to the invention described in claim 1, all of the light emitted from the low beam LED and directed downward is retroreflected by the retroreflective beads applied to the entire inner surface of the shade and reliably returned to the low beam LED. The light beam is directed upward by a reflector built in the low beam LED, reflected by a reflector provided in the headlamp, and irradiated downward on the road surface. For this reason, the light from the low beam LED is effectively used for the low beam, thereby increasing the light intensity of the low beam.

  According to the second aspect of the invention, the yellow light contained in the light emitted from the low beam LED is mixed again with the blue fluorescent dye applied to the inner surface of the shade and converted into white light. The problem of unevenness (color separation) is solved.

It is a perspective view of the LED bulb for headlamps concerning the present invention. It is a top view of the LED light bulb for headlamps which concerns on this invention. It is sectional drawing of LED explaining the principle of retroreflection in the LED bulb for headlamps which concerns on this invention. It is sectional drawing of LED and a shade explaining the principle of retroreflection in the LED bulb for headlamps concerning the present invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 is a perspective view of an LED bulb for a headlamp according to the present invention, FIG. 2 is a plan view of the LED bulb for the headlamp, and FIG. 3 is a sectional view of the LED for explaining the principle of retroreflection in the LED bulb for the headlamp. 4 is a cross-sectional view of the LED and shade for explaining the principle of retroreflection in the headlamp LED bulb, and the headlamp LED bulb (hereinafter simply referred to as “LED bulb”) 1 shown in FIG. It is used as a light source of a headlamp (not shown) arranged on the front left and right.

  A headlamp comprising the LED bulb 1 according to the present invention has a function capable of switching light distribution between a high beam (running beam) and a low beam (passing beam) with a single lamp, and its configuration is Although not shown, the LED bulb 1 according to the present invention and a reflector that reflects light emitted from the LED bulb 1 in a predetermined direction in a lamp chamber defined by a transparent outer lens that covers the housing and the front opening thereof. It is configured to accommodate.

  Thus, as shown in FIGS. 1 and 2, the LED bulb 1 according to the present invention includes an aluminum metal round bar-like support 2 that extends horizontally in the front-rear direction. In order to obtain a thickness that reproduces the filament dimensions of the bulb, a notch 2A that is notched in a concave shape is formed on both sides. A rectangular flat plate-like substrate 3 is fixed to each flat vertical surface of each notch 2A formed on the left and right side portions of the support 2, and each substrate 3 has four high beam-use substrates. The LED 4 and the low beam LED 5 are respectively mounted, and one shade 6 is fixed.

  The four high beam LEDs 4 and the low beam LED 5 are arranged in parallel in the front-rear direction (left and right direction in FIGS. 1 and 2), and the low beam LED 5 is located in front of the high beam LED 4 (left side in FIG. 1). The shade 6 is fixed below the low beam LED 5. Here, the shade 6 is made of metal and is formed into a long and narrow bowl shape so as to cover the low beam LED 5 from below. As shown in FIG. 4, the entire inner surface of the shade 6 is a fine spherical retroreflective bead. 7 is applied by a technique such as water transfer. Further, a blue fluorescent dye is applied to at least a portion of the inner surface of the shade 6 which is irradiated with yellow light. Note that the retroreflective beads 7 have a function of returning light incident thereon to the incident direction again.

  Thus, in the LED bulb 1 according to the present embodiment, the substrate 3, the high beam LED 4 and the low beam LED 5 mounted on the substrate 3, and the shade 6 are arranged as a set on the left and right sides of the support 2. Has been.

  In addition, a circular fixture (base) 8 is fixed to the base end portion (rear end portion) of the support 2. Although not shown in the figure, the wiring connected to the substrate 3 is drawn out from the rear, and terminals for supplying power to the high beam LED 4 and the low beam LED 5 are provided at the tip of the wiring. These are electrically connected to a power source (not shown) such as a vehicle headlamp circuit.

  Thus, the LED bulb 1 configured as described above is inserted into the lamp chamber from the circular hole formed in the back surface of the headlamp housing with the support 2 first, and the whole is rotated. Then, the plurality of locking pieces 8a on the outer periphery of the fixing metal 8 are locked to the inner peripheral edge of the insertion hole of the housing, thereby being fixed to the housing by the bayonet method.

  Here, the details of the configuration of the low beam LED 5 will be described with reference to FIG. The basic configuration of the high beam LED 4 is the same as that of the low beam LED 5, and therefore illustration and description thereof are omitted.

  The low beam LED 5 is provided on the package substrate 10, the anode electrode 11 and the cathode electrode 12 covering the periphery of the package substrate 10, the blue LED chip 13 mounted on the cathode electrode 12, and the package substrate 10. A reflector 14 and an encapsulating resin 15 filled in a space in the reflector 14 are provided.

  The blue LED chip 13 is electrically connected to the anode electrode 11 and the cathode electrode 12 by bonding wires 16 and 17, respectively. The reflector 14 has a tapered reflecting surface 14a. The encapsulating resin 15 contains a phosphor, which is excited by blue light emitted from the blue LED chip 13 and emits a complementary yellow color. For this reason, this yellow and the blue light emitted from the blue LED chip 13 are mixed, and pseudo white light is emitted from the low beam LED 5.

  In the LED bulb 1 configured as described above, when a current is selectively supplied from a power source (not shown) such as a headlamp circuit to the high beam LED 4 or the low beam LED 5 to emit light, the head including the LED bulb 1 is provided. The light distribution of the lamp is switched to a high beam or a low beam.

  That is, when a current is supplied to each of the four high beam LEDs 4 disposed on the left and right sides of the support 2 of the LED bulb 1, these high beam LEDs 4 are activated to emit light and are emitted from the high beam LEDs 4. Of the white light that travels, the downward light is reflected upward by a reflector provided in the headlamp, so that an upward high beam is emitted from the headlamp and illuminated far away.

  On the other hand, when a current is supplied to each of the four low beam LEDs 5 arranged on the left and right sides of the support 2 of the LED bulb 1, these low beam LEDs 5 are activated to emit light and are emitted from the low beam LEDs 5. Light (incident light) L1 (see FIG. 3 and FIG. 4) heading downward among the white light to be received is received by the shade 6 and retroreflected. That is, since the retroreflective beads 7 are applied to the entire inner surface of the shade 6 as described above, all of the light L1 directed to the shade 6 is retroreflected by the retroreflective beads 7 as shown in FIGS. Then, the retroreflected light L2 returns to the low beam LED 5 again. The retroreflected light L2 returning to the low beam LED 5 again is reflected by the reflection surface 14a of the reflector 14 of the low beam LED 5, and the reflected light L3 travels upward. The reflected light L3 emitted upward from the LED bulb 1 is reflected downward by a reflector provided in the headlamp, and is irradiated on the road surface as a low beam. There is no glare.

  As described above, in the LED bulb 1 according to the present embodiment, all of the light emitted from the low beam LED 5 and traveling downward is retroreflected by the retroreflective beads 7 applied to the entire inner surface of the shade 6. Thus, the light beam is surely returned to the low beam LED 5, directed upward by the reflector 14 built in the low beam LED 5, reflected by the reflector provided in the headlamp, and irradiated downward on the road surface. Is done. For this reason, the light from the low beam LED 5 is effectively used for the low beam, and as a result, the light intensity of the low beam is increased.

  In the present embodiment, the high-beam LED 4 and the low-beam LED 5 mounted on the substrate 3 are arranged on both the left and right sides of the support 2, so that the light emitted from each LED 4, 5 spreads left and right, and the LED bulb 1 The light emission range of is expanded.

  Further, in the present embodiment, since the blue fluorescent dye is applied to at least a portion of the shade 6 that is irradiated with yellow light, the yellow fluorescent light included in the light emitted from the low beam LED 5 is applied to the inner surface of the shade 6 and It is mixed again and converted into white light. For this reason, the problem of color unevenness (color separation) due to the pseudo luminescent color is solved, and the problem on the security standard does not occur.

  In addition, the above embodiment shows an example of the configuration of the LED bulb for headlamp according to the present invention, and the shape of the support and the number and arrangement of the LEDs supported by the support can be arbitrarily set. Of course there is.

DESCRIPTION OF SYMBOLS 1 LED lamp for headlamps 2 Support body 3 Substrate 4 LED bulb for high beam 5 LED bulb for low beam 6 Shade 7 Retroreflective bead 8 Fixing bracket (cap)
DESCRIPTION OF SYMBOLS 10 Package substrate 11 Cathode electrode 12 Anode electrode 13 Blue LED chip 14 Reflector 15 Encapsulating resin 16, 17 Bonding wire L1 Incident light L2 Retroreflected light L3 Reflected light

Claims (2)

A high beam LED and a low beam LED mounted on a vehicle headlamp that can switch light distribution between a high beam and a low beam, a shade that blocks a part of light emitted from the low beam LED, and the LED In a LED lamp for headlamps comprising a reflector that reflects light emitted from the lamp in the direction of the optical axis of the lamp,
The shade is provided on the substrate and is positioned between the LED and the reflector in the left-right direction,
The optical axis of the LED is perpendicular to the lamp optical axis direction,
An LED bulb characterized in that retroreflective beads are applied to the entire inner surface of the shade. 2. The LED lamp for a headlamp according to claim 1, wherein a blue fluorescent dye is applied to at least a portion of the shade that is irradiated with yellow light.

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