JP5150133B2 - LED lamp for headlight light source - Google Patents

Description

  The present invention relates to an LED lamp for a headlamp light source, and more particularly to an LED for a headlamp light source in which a lamp house surrounding an LED element forms part of a light distribution suitable for a vehicle lamp.

  Conventionally, in a vehicle headlamp using an LED lamp as a light source, a structure has been proposed in which the LED lamp has light distribution characteristics required for the headlamp. As shown in FIG. 9, the LED chip 51 mounted on the base portion 50 is sealed with a phosphor layer 52, and a silicone gel layer 53, a shielding member 54, and a window glass-like member 55 are sequentially disposed thereabove. Is provided.

  In this case, the shielding member 54 covers a part of the phosphor layer 52 via the silicone gel layer 53, and white light emitted from the phosphor layer 52 or light having a color tone close to white light is irradiated in the irradiation direction by a projection lens or the like. By appropriately setting the shape of the shielding member 54 when projected, a desired light distribution pattern such as a light distribution pattern of a passing beam can be formed.

Further, the shielding member 54 has a surface facing the LED chip 51 as a mirror surface having a sawtooth cross section, for example, so that the light emitted from the phosphor layer 52 and reflected by the shielding member 54 is within the phosphor layer 52. Then, the light is emitted from the phosphor layer 52 again. Therefore, since the light reflected by the shielding member 54 can be collected and used as the irradiation light, a decrease in the amount of irradiation light by the shielding member 54 can be suppressed. (For example, refer to Patent Document 1).
JP 2005-5193 A

  By the way, the LED lamp 56 having the above structure collects and uses the light reflected by the shielding member 54 forming the light distribution pattern of the LED lamp 56 as irradiation light, thereby improving the light utilization efficiency. At least some of the light reflected by the shielding member 54 is absorbed and scattered by the phosphor layer 52, and it is difficult to say that the light is completely recovered and used.

  In addition, a special component that is not used in the general-purpose LED lamp, such as the shielding member 54, is required, which increases the manufacturing cost accordingly.

  Therefore, the present invention was devised in view of the above problems, and an object of the present invention is to form a desired light distribution pattern with high light utilization efficiency and to produce an LED lamp for a headlamp light source that is inexpensive to manufacture. Is to provide.

In order to solve the above-mentioned problem, the invention described in claim 1 of the present invention is that a plurality of LED elements mounted on a base are surrounded by a lamp house having openings, and the LED elements are made of resin or phosphor. A pair of side walls opposed to each other across the LED element of the lamp house, the height of one side wall being equal to or higher than the height of the other side wall, It said one side wall has two inner surfaces sandwiching the step portion, the angle of one of the inner surface of said one side wall and the base is less than 180 ° larger than 90 °, and said one of the inner surface, the other A cut-off line of a light distribution pattern that is located on the LED element side with respect to the inner surface of the light source and in which the inner peripheral edge of the opening end portion of the one side wall is formed by irradiation light of the LED lamp for headlamp light source At least part of It is characterized by forming.

The invention described in claim 2 of the present invention, Oite to claim 1, wherein the base is characterized in that a printed circuit board having a circuit pattern made of a metal conductor on both sides was formed.

The invention described in claim 3 of the present invention is characterized in that, in any one of claims 1 and 2 , the resin is formed by mixing one or more kinds of phosphors in a translucent resin. It is.

According to a fourth aspect of the present invention, in any one of the first and second aspects, a translucent resin is provided so as to cover the phosphor.

  The LED lamp for a headlamp light source according to the present invention forms at least a part of a cut-off line of a light distribution pattern suitable for a vehicle lamp by a lamp house surrounding an LED element.

  As a result, an excellent effect is achieved in that a desired light distribution pattern can be formed with high light utilization efficiency and manufacturing is possible at low cost.

  Embodiments of the present invention will be described in detail with reference to FIGS. The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. Unless stated to the effect, the present invention is not limited to these embodiments.

  FIG. 1 is a perspective view of an embodiment of an LED lamp for a headlamp light source according to the present invention. As shown in FIG. 1, the present embodiment includes a printed circuit board 1 serving as a base, a lamp house 2 disposed on one surface of the printed circuit board 1, and a plurality of components mounted on the printed circuit board 1 in the lamp house 2. The LED element 3 and a sealing resin 4 that fills the lamp house 2 and seals the LED element 3 are provided.

  The printed circuit board 1 has circuit patterns 6 made of metal conductors formed on both surfaces of a base material 5, mounting electrodes 7 connected to both surfaces at both ends are formed at both ends, and each LED element 3 is mounted at the center. A die bonding pad to be placed and a wire bonding pad for connecting the bonding wire 17 are formed. In FIG. 1, the die bonding pad and the wire bonding pad are not shown.

  The lamp house 2 is made of a highly reflective material such as a white resin material, a white ceramic material, or a white metal material, or a low reflectivity or non-reflective material such as a black resin material, a black ceramic material, or a black metal material. . The selection of the white and black materials is mainly determined by whether the light distribution pattern of the irradiation light from the headlamp light source LED lamp 8 is important or the light quantity is important.

  The lamp house 2 has a substantially cylindrical shape having an opening 9 on the upper side (opposite side of the printed circuit board 1), and a die bonding pad and a wire bonding pad not shown form a part of the inner bottom surface. Yes.

  A pair of side walls 10, 11 facing each other along the mounting direction in which a plurality of LED elements 3 described later among the four side walls 10, 11, 12, 13 of the lamp house 2 are mounted substantially linearly. The height of one side wall 10 is equal to or higher than the height of the other side wall 11. Further, the inner peripheral edge 15 of the opening end 14 of one side wall 10 has a stepped portion 15c in the opposing direction of the pair of side walls 10 and 11, and one inner peripheral edge 15a sandwiches the stepped portion 15c. It is located closer to the LED element 3 than the inner peripheral edge 15b.

  The intersecting lines formed by the inner surfaces 16 a and 16 b including the inner peripheral edges 15 a and 15 b of the opening end 14 of the side wall 10 with the printed circuit board 1 are located on the same straight line.

  The LED element 3 is fixed (die-bonded) to each of die bonding pads formed in a plurality of substantially straight lines via a bonding member such as solder or conductive adhesive, and the lower electrode and the die bonding pad of the LED element 3 are fixed. And electrical continuity. In addition, the other end of the bonding wire 17 whose one end is connected to the upper electrode of the LED element 3 is connected to each wire bonding pad (wire bond), and the upper electrode of the LED element 3 and the wire bonding pad Electrical continuity is achieved.

  Then, the sealing resin 4 in which the phosphor is mixed in the translucent resin is filled in the lamp house 2, and all the LED elements 3 and the bonding wires 17 are resin-sealed with the sealing resin 4. The translucent resin protects the LED element 3 from an external environment such as moisture, dust, and gas, and protects the bonding wire 17 from mechanical stress such as vibration and impact. The translucent resin forms an interface with the light emitting surface of the LED element 3, and also has a function of efficiently emitting the emitted light of the LED element 3 from the light emitting surface of the LED element 3 into the translucent resin. Have.

  In this case, in the present embodiment, the irradiation light emitted from the LED lamp for the headlamp light source is assumed to be white light or light having a color tone close to white light. Therefore, the emission color and translucency of the LED element 3 are assumed. The combination with the phosphor mixed in the resin is set as follows.

  First, when the LED element 3 is a blue LED element that emits blue light, a yellow phosphor that is wavelength-converted into yellow light that is excited by blue light and becomes a complementary color of blue is used, and one of blue light emitted from the blue LED element is used. The unit obtains light having a color tone close to white light by additive color mixture of yellow light wavelength-converted by exciting the yellow phosphor and blue light emitted from the blue LED element.

  Similarly, when the LED element 3 is a blue LED element, blue light emitted from the blue LED element using a mixture of two types of phosphors that are excited by blue light and wavelength-converted into green light and red light, respectively. It is also possible to obtain white light by additive color mixture of green light and red light whose wavelengths are converted by exciting part of the phosphor and blue light emitted from the blue LED element.

  Further, in the case where the LED element 3 is an ultraviolet LED element that emits ultraviolet rays, a mixture of three kinds of phosphors that are excited by the ultraviolet rays and convert wavelengths of blue light, green light, and red light, respectively, is emitted from the ultraviolet LED element. It is also possible to obtain white light by additive color mixing of blue light, green light and red light whose wavelength has been converted by exciting the phosphor with the ultraviolet light.

  In any case, it is possible to obtain light of various color tones other than white light or light of a color tone close to white light by appropriately combining the wavelength of light emitted from the LED element 3 and the type of phosphor. is there.

  2 is a cross-sectional view taken along the line AA in FIG. The LED element 3 is a blue LED element, the phosphor mixed in the sealing resin 4 of the blue LED element is a yellow phosphor, and the irradiation light emitted from the LED lamp 8 for the headlamp light source has a color tone close to white light. Let it be light. Then, due to the light distribution of the LED element 3 and the light scattering property of the phosphor, the light distribution of the light emitted from the sealing resin 4 becomes a Lambertian distribution 18 as shown in FIG.

  Of the light emitted from the LED element 3 positioned between the side wall 10 and the side wall 11 of the lamp house and guided through the sealing resin 4 and emitted from the sealing resin 4, the side wall 10. The light L1 traveling in a direction other than the inner surface 16a is directly irradiated to the outside of the headlamp light source LED lamp 8. On the other hand, the light L2 emitted from the sealing resin 4 toward the inner surface 16a of the side wall 10 is reflected by the inner surface 16a and the path is bent.

  As a result, the light distribution pattern formed in the direction of the side wall 10 and the side wall 11 between which the light emitted from the LED element 3 and guided through the sealing resin 4 and emitted from the sealing resin 4 sandwiches the LED element 3 is: An arrangement in which the side wall 10 side of the straight line S connecting the LED element 3 and the inner peripheral edge 15a of the opening end 14 of the side wall 10 is cut off from the Lambertian light distribution 18 formed by the light emitted from the sealing resin 4. Light distribution A is obtained.

  Of the light emitted from the LED element 3 located between the side wall 10 and the side wall 11 of the lamp house and guided through the sealing resin 4 and emitted from the sealing resin 4, the side wall 10. The light L3 traveling in a direction other than the inner surface 16b is irradiated to the outside of the headlamp light source LED lamp 8 as it is. On the other hand, the light L4 radiated from the sealing resin 4 toward the inner surface 16b of the side wall 10 is reflected by the inner surface 16b and the course is bent.

  As a result, the light distribution pattern formed in the direction of the side wall 10 and the side wall 11 between which the light emitted from the LED element 3 and guided through the sealing resin 4 and emitted from the sealing resin 4 sandwiches the LED element 3 is: An arrangement in which the side wall 10 side of the straight line T connecting the LED element 3 and the inner peripheral edge 15b of the opening end 14 of the side wall 10 is cut from the Lambertian light distribution 18 formed by the light emitted from the sealing resin 4. Light distribution B is obtained.

  In both the light distribution A and the light distribution B, the position where the irradiation intensity is maximum is near the upper side of the side wall 10, and when the side wall 10 has a constant height, the LED element 3 and the inner surfaces 16 a and 16 b of the side wall 10. When the distance between the LED element 3 and the inner surfaces 16a and 16b of the side wall 10 is constant, the height of the side wall 10 increases and the height of the side wall 10 increases.

  In addition, as for the relationship between the height of the LED element 3 and the height of the side wall 10, for example, when the height of the LED element 3 is 100 μm, the height of the side wall 10 is preferably in the range of 300 μm to 1 mm. In other words, the height of the side wall 10 is preferably in the range of 3 to 10 times the height of the LED element 3.

  Incidentally, in the present embodiment, the LED element has a height of 100 μm (0.1 mm) and the side wall has a height of 500 μm (0.5 mm).

  If the height of the side wall 10 is smaller than three times the height of the LED element 3, a region (cut-off region) where the Lambertian light distribution 18 is cut off is reduced, and the effect of providing the side wall 10 is reduced. On the other hand, when the height of the side wall 10 is larger than 10 times the height of the LED element 3, the area (cut-off area) to be cut out of the Lambertian light distribution 18 is increased, the irradiation area is reduced, and the side wall 10 is reduced. As compared with the effect of providing the above, the disadvantage that the height of the LED lamp for the headlamp light source is increased, and the effect of providing the side wall 10 is relatively reduced.

  FIG. 3 shows a light distribution pattern 19 formed by the irradiation light of the headlamp light source LED lamp 8 of this embodiment, and this light distribution pattern 19 shows the light distribution of the passing beam in the left-hand traffic. It is.

  The light distribution pattern 19 includes light directed upward from the horizontal reference line H so that the left half of the drawing does not dazzle the driver of the oncoming vehicle with respect to the vertical reference line V that is the center of the vehicle. The right half has a light distribution LPL shape that includes light directed upward from the horizontal reference line H so that the driver can easily see the signs and the like on the roadside belt.

  Accordingly, when verifying at which part of the LED lamp 8 for the headlight source the respective points P1, P2, P3, P4 on the upper edge of the light distribution pattern 19 and the cut-off lines CL1, CL2, CL3 are formed, Each point P1, P2, P3, P4 of the light pattern 19 is formed by each point Q1, Q2, Q3, Q4 of the inner peripheral edge 15 of the opening end 14 of the side wall 10 of the headlamp light source LED lamp 8 and cut. The offline lines CL1, CL2, and CL3 are formed by inner peripheral edges 15a and 15b and a stepped portion 15c of the opening end 14 of the side wall 10, respectively.

  The lower edge CL4 of the light distribution pattern 19 reflects the outer edge of the light distribution of the light emitted from the sealing resin 4 of the headlamp light source LED lamp 8 as it is. That is, the cut-off lines CL1, CL2, and CL3 of the light distribution pattern 19 are formed by the inner and outer peripheral edges 15a and 15b and the step portion 15c of the opening end portion 14 of the headlamp light source LED lamp 8.

  Then, it is not necessary to provide a light distribution control function to the reflector and front lens that have conventionally been responsible for the light distribution of the lamp, and it is possible to reduce the lamp by simplifying the design of the members constituting the lamp and simplifying the mold. Pricing is possible.

  In addition, when changing the light distribution pattern of the lamp, the desired light distribution pattern can be realized simply by changing the shape of the side wall of the LED lamp for the headlamp light source. Development time and labor costs can be reduced by shortening the development period of the new lamp. Etc. are reduced.

  Furthermore, since most of the light emitted from the LED element can be used as irradiation light, a desired light distribution pattern can be formed with high light utilization efficiency.

  In addition, the shape shown in FIGS. 4-6 can be considered for the inner surface of the side wall which participates in control of the light distribution pattern of the LED lamp for headlamp light sources, for example. In FIG. 4, the angle α1 formed by the printed board 1 surface and the inner surface 16a of the side wall 10 is 90 ° (α1 = 90 °). In this case, the inner surface 16a and the inner surface 16b of the side wall 10 are parallel and the inner surface 16a is the inner surface. It will be located in the LED element 3 side rather than 16b. The inner peripheral edge 15a of the opening end 14 of the side wall 10 of the headlamp light source LED lamp 8 forms a cut-off line CL1 at the upper edge of the light distribution pattern LPR that irradiates the road center side of the light distribution pattern 19. Yes (see FIG. 3).

  FIG. 5 shows the side wall 10 employed in the above embodiment, in which the angle α2 formed between the printed circuit board 1 surface and the inner surface 16a of the side wall 10 is greater than 90 ° and smaller than 180 ° (90 ° <α2 <180 °). In this case, the inner peripheral edge 15a of the opening end 14 of the side wall 10 is positioned closer to the LED element 3 than the inner peripheral edge 15b. As described in the description of the embodiment, the inner peripheral edge 15a of the opening end 14 of the side wall 10 of the headlamp light source LED lamp 8 is a light distribution pattern LPR that irradiates the road center side of the light distribution pattern 19. The cut-off line CL1 of the upper edge is formed (see FIG. 3).

  6 shows an angle α3 formed by the surface of the printed circuit board 1 and a part of the inner surface 16a of the side wall 10 (the inner surface located below) of 180 ° (α3 = 180 °). In this case as well, The inner peripheral edge 15a of the opening end 14 of the side wall 10 is positioned closer to the LED element 3 than the inner peripheral edge 15b. The inner peripheral edge 15a of the opening end 14 of the side wall 10 of the headlamp light source LED lamp 8 is The cut-off line CL1 at the upper edge of the light distribution pattern LPR that irradiates the road center side of the light distribution pattern 19 is formed (see FIG. 3).

  However, the difference from FIG. 5 is that the cut-off line CL1 of the light distribution pattern LPR becomes clearer, the visibility in front of the vehicle is improved for the driver, and the dazzling to the driver of the oncoming vehicle is further reduced. It can be done.

  In the present embodiment, the LED element is resin-sealed with a sealing resin in which a phosphor is mixed in a translucent resin so that the light emitted from the LED lamp for the headlamp light source is light with a color tone close to white light. However, as another structure, as shown in FIG. 7, a method of covering the LED element 3 with the phosphor 20 and filling the light-transmitting resin 21 thereon is also possible.

  In some cases, the light emitted from the LED element may be directly used as the irradiation light of the LED lamp for the headlamp light source. In this case, the LED element 3 is sealed with a translucent resin as shown in FIG. Obviously, it should be stopped.

  As described above, the headlamp light source LED lamp of the present invention has an excellent effect of forming a desired light distribution pattern with high light use efficiency and being manufactured at a low cost. is there.

It is a perspective view of the embodiment of the present invention. It is AA sectional drawing of FIG. It is a schematic diagram of the light distribution pattern formed in this embodiment of this invention. It is sectional drawing of other embodiment of this invention. It is sectional drawing of embodiment of this invention. It is sectional drawing of other embodiment of this invention. It is sectional drawing of other embodiment of this invention. It is sectional drawing of other embodiment of this invention. It is sectional drawing which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printed circuit board 2 Lamp house 3 LED element 4 Sealing resin 5 Base material 6 Circuit pattern 6
7 Mounting electrode 8 LED lamp for headlamp light source 9 Opening 10 Side wall 11 Side wall 12 Side wall 13 Side wall 14 Open end 15 Inner edge 15a, 15b Inner edge 15c Stepped parts 16a, 16b, 16c Inner surface 17 Bonding wire 18 Lambertian Light distribution 19 Light distribution pattern 20 Phosphor 21 Translucent resin

Claims (4)

A plurality of LED elements mounted on a base is surrounded by a lamp house having an opening, and the LED elements are sealed with a resin or a phosphor. The pair of side walls facing each other across the LED element has a height of one side wall equal to or higher than the height of the other side wall, and the one side wall has two inner surfaces sandwiching a stepped portion, and the base and the side wall The angle formed by one inner surface of one side wall is larger than 90 ° and smaller than 180 °, and the one inner surface is located closer to the LED element than the other inner surface , and the opening end portion of the one side wall An LED lamp for a headlamp light source, wherein an inner peripheral edge forms at least a part of a cut-off line of a light distribution pattern suitable for a vehicle lamp formed by irradiation light of the LED lamp for headlamp light source.   The LED lamp for a headlamp light source according to claim 1, wherein the base is a printed circuit board on which circuit patterns made of metal conductors are formed on both sides.   The LED lamp for a headlamp light source according to any one of claims 1 and 2, wherein the resin is formed by mixing one or more kinds of phosphors with a translucent resin.   3. The headlamp light source LED lamp according to claim 1, wherein a translucent resin is provided so as to cover the phosphor.

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