JP2007005322A - Projection type led lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projection type LED lamp improved in reliability by solidification of a light source, cost reduction by simplification of a structure, and also in miniaturization at the same time. <P>SOLUTION: This projection type LED lamp 1 is composed by arranging an LED chip 2 in the vicinity of a focal point of a projection means having the focal point and by forming a shielding member 6 covering a part of the LED chip 2 into a shape allowing a light distribution suitable for a vehicular headlight to be provided when the light from the LED chip 2 is expanded and projected in the irradiation direction by a projection means such as a projection lens 10, whereby the light is projected by the projection lens 10 in the irradiation direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an LED lamp, and more particularly to a configuration of an LED lamp used as a light source such as a vehicular lamp, and includes a headlamp and an auxiliary headlamp. In the related art, the present invention relates to a configuration of an LED lamp suitable for use as a light source such as a vehicular lamp for illumination having a light distribution characteristic that has not been conventionally adopted.

Conventionally, when an LED lamp is used as a light source for an illumination lamp such as a flashlight, for example, a large LED chip is accommodated in a large package and, for example, a current of several tens to several hundred milliamperes is applied to obtain a light amount It is said. At the same time, by making a large package, heat generated in the LED chip when lit is effectively conducted to the outside through the package, and radiated to the atmosphere etc. The chip can be prevented from being deteriorated or damaged. (For example, see Patent Document 1)
Japanese Patent Laid-Open No. 2004-192098

  However, when the lamp that uses the LED lamp as the light source is a vehicle lamp such as a headlamp, the light distribution characteristics are strictly controlled so that the light emitted in front does not cause the driver of the oncoming vehicle to be dazzled. Is set according to related standards, etc., and the configuration on the lamp side such as a headlight is formed assuming an incandescent bulb that radiates the light flux almost uniformly in all directions. However, simply replacing the LED lamp that emits light with a bias in one direction causes a problem that a product satisfying the light distribution characteristics cannot be obtained.

  As a specific means for solving the above-described conventional problems, the present invention is an LED lamp that irradiates light from an LED light source by a projection means, and includes an LED light emitting unit that includes an LED chip that irradiates light in a biased manner. A projection means for projecting light from the LED light emitting section forward in the irradiation direction; a projection means for projecting light from the LED light emitting section forward in the irradiation direction; and located between the LED light emitting section and the projection section, A shielding member disposed near the LED light emitting unit, and the LED light emitting unit includes an LED chip or an LED chip and a phosphor, and the projection unit enlarges and projects the light from the LED light emitting unit in the irradiation direction. Sometimes, by providing a projection type LED lamp characterized in that it is arranged to project the shape of the portion of the LED light emitting part that is not covered by the light shielding member. Light distribution characteristics defined even when employing the LED lamp as a light source is intended to solve the problems as those obtained accurately and easily.

  As described above, according to the present invention, when an LED chip is disposed in the vicinity of the focal point of a projecting unit having a focal point, and the light from the LED chip is enlarged and projected in the irradiation direction by the projecting unit, the vehicle headlamp is used. Projection-type LED lamps that are provided with a shielding member that covers a part of the LED chip in a shape that provides light distribution characteristics suitable for lamps, etc., so that the light distribution shape with accurate characteristics is a solid structure projection Can be obtained by an extremely simple means of enlarging and projecting the shape of the light emitting part of the LED lamp in the irradiation direction with a projection lens or a reflector, improving the reliability by solidifying the light source and the cost by simplifying the configuration In addition to the down effect, the present invention has an extremely excellent effect of enabling downsizing at the same time.

  Below, this invention is demonstrated in detail based on embodiment shown in a figure. 1 and 2 is a projection type LED lamp (hereinafter abbreviated as LED lamp 1) according to the present invention. In this LED lamp 1, an LED chip 2 is mounted on a base 3. Has been done.

  The base 3 is provided with a base portion 3a formed of a metal member having excellent thermal conductivity such as copper, and a lead frame 3b formed of the same metal member. The base portion 3a and the lead frame 3b are Insulation is performed by an insulating layer 3c formed of an insulating member such as a resin member. The LED chip 2 mounted on the base portion 3a is wired to the lead frame 3b by a gold wire 4 or the like, and can be turned on by power supply from the outside.

  Here, considering the necessary conditions when the LED lamp 1 is used as a light source for a headlamp, white or a single yellow color is used as a specified color as a lamp color. In many cases, the LED chip 2 that directly emits white light does not exist, but in order to obtain white light, the phosphor 5 is used in combination.

  As the first method, the blue light emitting LED chip 2 and the yellow light emitting phosphor 5 are combined, and the direct blue light from the LED chip 2 and the light from the LED chip 2 are used. Yellow light from the phosphor 5 to be excited is mixed to obtain white light. As a second method, the LED chip 2 that emits ultraviolet light and the phosphor 5 that emits light of the three primary colors of red (R), green (G), and blue (B) are combined. The direct light from the LED chip 2 is not used as the irradiation light, but the irradiation light from the phosphor 5 is used as the irradiation light of the LED lamp 1.

  Therefore, in the present invention, the following description will be given on the assumption that the LED light emitting unit 8 in which the LED chip 2 and the phosphor 5 are combined is used as the light source of the headlamp. For example, when the lamp color is required to be yellow For example, the direct light from the LED chip 2 can be used as the light source light, but in this case as well, the present invention can be implemented. In this case, the white LED light emitting unit 8 is replaced with the LED chip. Replace with 2.

  Further, since the LED chip 2, the gold wire 4, the phosphor 5 and the like are mechanically weak and not sufficiently resistant to humidity and the like, a lens-like member formed of a transparent resin or the like, or a window glass shape Covered with a member (illustrated in the example of the window glass-like member 6) and sealed against the outside air with the base portion 3a to prevent damage due to contact with each of the above parts, deterioration due to humidity, etc. It is said that. The space between the lens-like member or window glass-like member and the LED light-emitting portion 8 is preferably filled with an inert gas, silicone gel (shown here as an example of silicone gel 9), or the like.

  In addition, in the LED lamp 1 of the present invention, a shielding member 7 is provided. The shielding member 7 covers a part of the phosphor 5, for example, projects light emitted from the phosphor 5. For example, a desired shape such as a light distribution shape for passing is obtained when projected in the irradiation direction.

  Therefore, both the window glass-like member 6 and the shielding member 7 exist in front of the phosphor 5 in the irradiation direction, and the window glass-like member 6 is transparent and the shielding member 7 is opaque. May be installed on the front side, and further, for example, by using the inner and outer surfaces of the window glass-like member 6, the shielding member 7 is formed by painting with an opaque paint or vapor deposition of a metal member. Is also free.

Further, when the headlamp that employs the LED lamp 1 as a light source is a light source for an infrared night vision device (night vision), the window glass-like member 6 is a member that passes infrared rays and shields visible light. As the shielding member 7, a member that shields at least light rays from infrared rays to visible light may be used. Further, when the shielding member 7 is a vapor deposition film of a metal member, deterioration due to oxidation can be considered, so that it may be covered and protected with a SiO ₂ film as indicated by reference numeral 12 in FIG.

  3 is an example of passing light distribution in left-hand traffic, and in this passing light distribution HB, the right half from the center line of the own vehicle is dazzling to the driver of the oncoming vehicle. It has a light distribution shape that does not contain any upward light so that it does not occur, but the left half has a 15 ° rise to the left, called an elbow, for easy reading of signs and the like on the roadside belt. A portion for generating upward light is provided.

  In the present invention, the shape of the portion of the phosphor 5 that is not covered by the shielding member 7 is similar to the passing light distribution HB described above, and the phosphor 5 thus obtained By projecting the shape in the irradiation direction P by the projection lens 10 as shown in FIG. 4, a passing light distribution HB can be obtained. When the LED chip 2 is covered with the shielding member 7, the LED chip 2 is covered at the maximum brightness or a position close to the maximum brightness so that the front horizontal direction has the maximum brightness in order to secure a far field of view. Is done.

  In addition, after projecting with the projection lens 10, the top, bottom, left and right are reversed. Therefore, if the LED lamp 1 is attached to the headlamp in a state rotated by 180 ° and projected with the projection lens 10 in this state, the passing light distribution is achieved. An erect image as HB is obtained. Further, by changing the shape of the shielding member 7, it is possible to form a light distribution shape such as a light distribution shape without an elbow or a light distribution shape for traveling.

  Here, if the shield member 7 is further explained, the shield member 7 shields the light from the LED chip 2, so that if the half is covered, the amount of light is also halved. This causes a loss in the amount of light. Here, as a result of the inventor's investigation, it was confirmed that at least the surface of the shielding member 7 facing the LED chip 2 has a slight influence on the shape of the light distribution characteristics after projection.

  That is, when the surface of the shielding member 7 (projection lens 10 side) reflects light, it is re-projected by the projection lens 10 and has a high possibility of affecting the shape of the light distribution characteristic. However, in the case of the back surface side, even if the mirror surface treatment is performed and the light from the LED chip 2 is reflected, it is only returned to the LED chip 2 side, so that the boundary between the phosphor 5 and the shielding member 7 is reduced. It does not substantially affect the shape, in other words, the shape of the light distribution characteristic.

  And since the light reflected on the back surface side of the shielding member 7 returns to the phosphor 5 again, the back surface of the shielding member 7 is mirror-finished and the phosphor 5 is covered as shown in FIG. For example, if the saw-tooth shaped portion 7a or the like that generates reflected light in the opposite direction is used, the brightness of the phosphor 5 is further improved. That is, the light reaching the back surface side of the shielding member 7 can be recovered as irradiation light, and as a result of the inventor's trial manufacture and measurement, an increase in light quantity of 15% or more was confirmed.

  In addition, as a result of the inventors' examination on the shielding member 7 performed simultaneously, it is preferable to project the focus of the projection lens 10 on the shielding member 7 in order to obtain the shape of the light distribution characteristic more accurately. When it is desired to obtain brightness in the light distribution characteristic, the projection lens 10 is preferably focused on the LED light emitting unit 8 (or the LED chip 2 when the lamp color is yellow) for projection. Therefore, if the LED chip 2 and the shielding member 7 are close to each other, they are almost in focus, which is convenient for both shape and brightness, and the distance between them should be 2 mm or less. If the thickness is preferably 1 mm or less, even better results can be expected.

  Further, as described above, when the LED light emitting unit 8 covered by the shielding member 7 is projected by the projection lens 10, a single plano-convex lens shape is often adopted for the projection lens 10, and as shown in FIG. 6. For example, there is a so-called chromatic aberration in which there is a difference in position between the position where the focus fb for blue is generated and the position where the focus fr for red is generated.

  In this case, if the shielding member 7 is installed close to one of the sides, the light / dark boundary line HL (see FIG. 3) where the shape of the shielding member 7 of the passing light distribution HB is projected is formed. Coloring occurs, and the lamp color cannot satisfy the requirement that it is a single color. As a solution to this, as shown in FIG. 7, the thickness t of the shielding plate 7 is, for example, a thickness ranging from the blue focal point fb to the red focal point fr. If a color is present, the mixed color approaches white and a specific color cannot be felt.

  Alternatively, as shown in FIG. 8, at least two thin shielding members 7 are prepared, and one is installed at the position of the blue focal point fb by using, for example, the front and back surfaces of the window glass-like member 6. The other sheet is placed at the position of the red focus fr. By doing so, the light and dark boundary line HL of the projected low light distribution HB is mixed with blue and red, which are in a complementary color relationship, and similarly to the example of the thick shielding member 7 described above, A specific color can be prevented from being felt.

  If the shielding member 7 is further described, in the projection lens 10, in addition to the chromatic aberration (Chromatic aberratin) described above, spherical aberration, astigmatism (Astigmatism), coma (Coma) When aberrations such as field curvature and distortion are generated and the shape of the LED light emitting unit 8 is projected, distortion of the shape or defocusing occurs due to these aberrations.

  Therefore, as the shielding member 7, for example, in order to cope with the curvature of field, if the focal plane of the projection lens 10 is curved in the same shape, a sharp light / dark boundary from the center to both left and right ends A line HL is obtained (provided that there is no influence of spherical aberration, astigmatism, and coma). Further, aberrations related to shape distortion, such as distortion, may be corrected on the shielding member 7 side so that the passing light distribution HB after projection has a desired shape.

  As described above, it is possible to cope with any aberration by means such as thickening, bending, or deforming the shielding member 7, but these detailed methods are a so-called projector type that employs the projection lens 10. Since it is already known in the lamp, further detailed explanation here is omitted.

  FIG. 9 schematically shows another embodiment of a headlamp that employs the LED lamp 1 according to the present invention as a light source. In FIG. 4, the headlamp includes one LED lamp 1 and one projection lens. It consisted of ten. However, the white LED light emitting portion 8 including the shielding member 7 can satisfy the standard of the passing light distribution HB on the shape surface, but may not satisfy the regulations such as the lack of central illuminance in terms of illuminance distribution. .

  Here, in the present invention, since the LED light emitting unit 8 having an extremely small area is directly projected, the projection lens 10 may be small in size, and therefore, the combination of the LED lamp 1 and the projection lens 10 is changed. Even if a plurality of lamps are prepared, they can be kept within the dimensions required for a headlamp.

  Therefore, in this embodiment, as one headlamp, a plurality of sets such as three sets of combinations of the LED lamp 1 and the projection lens 10 are prepared. The projection lens 10 may be the same as that of the first embodiment, but the projection lens 10 has the same magnification as that used in FIG. 4, the second projection lens 10b having a smaller magnification, Three types of small third projection lenses 10c are prepared, and all are projected in the same direction.

  FIG. 10 shows the passing light distribution HBs by the headlamp configured as described above, and the passing light distribution HBs is shaped to pass the passing light distribution HB obtained in the previous embodiment (see FIG. 3). The light distribution Ha from the first projection lens 10a, the light distribution Hb from the second projection lens 10b, and the light distribution Hc from the third projection lens 10c are superimposed and formed. ing

  By doing in this way, the light distribution Hc from the 3rd projection lens 10c with the lowest magnification is the brightest, and the light distribution Hc is arranged at the center of the passing light distribution HBs, so that the front of the vehicle. The front is the brightest and the distance is improved. If the number of combinations of the LED lamp 1 and the projection lens 10 and the magnification of each projection lens 10c are adjusted, the standard can be satisfied.

  Generally speaking, the light quantity of the LED lamp 1 is less than that of the conventional halogen light bulbs and metal halide discharge lamps. Therefore, means for increasing the light quantity by combining a plurality of LED lamps 1 It is very effective as a means for realizing a headlamp as a light source.

  Further, in the above description, in order to facilitate understanding, it is assumed that the final light distribution is obtained by superimposing the light distribution magnification ratios that are substantially the same shape, but this is the final one. The shapes of the passing light distributions may be formed by joining them appropriately. In short, it is only necessary to finally obtain a light distribution shape that satisfies the regulations.

  FIG. 11 shows an example of another projection method using the LED lamp 1 according to the present invention. In this example, a reflector 11 having a focus such as a rotating paraboloid is used instead of the projection lens 10 which is the previous projection method. Is projected in the irradiation direction P to obtain irradiation light having a predetermined light distribution shape.

  Here, therefore, in this projection method using the reflector 11 that forms a projected image with reflected light, the LED chip 2, the phosphor 5, the shielding member 7, and the like are opposed to the reflector, that is, with respect to the irradiation direction P. It will be installed close to the rear.

  At this time, if the reflector 11 is, for example, a multi-reflector in which a plurality of parabolic free-form surfaces are combined, the degree of freedom in forming the passing light distribution HB is high. Since no chromatic aberration is produced, a high-quality passing light distribution HB can be easily obtained. Further, as in the case of the projection lens, the headlamp may be configured by using a plurality of combinations of the LED lamp 1 and the reflector 11.

It is a perspective view which shows embodiment of the projection type LED lamp which concerns on this invention. It is sectional drawing which follows the AA line of FIG. It is explanatory drawing which shows the example of the passing light distribution characteristic obtained with the projection type LED lamp of this invention. It is explanatory drawing which shows a state when combining the projection type LED lamp which concerns on this invention with a projection lens. It is sectional drawing which shows the example of a structure of the shielding member of the projection type LED lamp which concerns on this invention. It is explanatory drawing which shows the example of the chromatic aberration which arises in a projection lens. It is sectional drawing which shows the example of another structure of the shielding member of the projection type LED lamp which concerns on this invention. It is sectional drawing which similarly shows the example of another structure of the shielding member of the projection type LED lamp which similarly concerns on this invention. It is explanatory drawing which shows the example at the time of comprising a headlamp with the combination of the several LED lamp for headlamp light sources, and a projection lens. It is explanatory drawing which shows the example of the formation means of the light distribution characteristic when combining a some projection type LED lamp and a projection lens. It is explanatory drawing which shows a state when combining the projection type LED lamp which concerns on this invention with a reflector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Projection type LED lamp 2 ... LED chip 3 ... Base 3a ... Base part 3b ... Lead frame 3c ... Insulating layer 4 ... Gold wire 5 ... Phosphor 6 ... Window glass-like member 7 …… Shielding member 7a …… Sawtooth shaped part 8 …… LED light emitting part 9 …… Silicone gel 10 …… Projection lens 11 …… Reflector 12 …… SiO ₂ film

Claims (8)

An LED lamp that emits light from an LED light source by a projection means,
An LED light-emitting unit including an LED chip that emits light in a biased manner;
Projection means for projecting light from the LED light emitting section forward in the irradiation direction;
Projecting means for projecting light from the LED light emitting part forward in the irradiation direction;
A shielding member located between the LED light emitting unit and the projection unit and disposed near the LED light emitting unit,
The LED light emitting unit includes an LED chip or an LED chip and a phosphor,
When the light from the LED light emitting unit is enlarged and projected in the irradiation direction by the projection means, the shape of the portion of the LED light emitting unit that is not covered with the light shielding member is projected so as to be projected. Projection type LED lamp.   2. The projection type LED lamp according to claim 1, wherein the shielding member is disposed with an interval of 2 mm or less from the LED light emitting portion.   The surface of the shielding member on the side where the mirror surface treatment is performed is provided with an inclination for reflecting light toward a direction in which the LED light emitting unit is not shielded. The projection type LED lamp as described.   The projection LED according to any one of claims 1 to 3, wherein the light shielding member is configured to shield at a ridge line passing through a portion where the highest luminance in the LED light emitting unit or a vicinity thereof is passed. lamp.   5. The projection LED lamp according to claim 1, wherein a wavelength conversion member is provided between the LED light emitting unit and the shielding member. The projection means uses a projection lens having a focal point;
The projection LED lamp according to any one of claims 1 to 5, wherein the focal point is a position of the shielding member or the LED light emitting unit or a position in the vicinity thereof. The LED light emitting part is a white LED light emitting part,
The projection type white LED lamp according to claim 6, wherein the shielding part has a thickness of at least the focal point fb for blue and the focal point fr for red in the projection lens.   The projection LED according to any one of claims 1 to 5, wherein the projection unit uses a reflector made of a reflective surface having a single focal point or a multi-reflector made of a plurality of reflective surfaces. lamp.

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