JP5940422B2 - Vehicle lighting - Google Patents

Description

  The present invention relates to a vehicular lamp.

  Conventionally, as a vehicular lamp such as a fog lamp for an automobile, light emitted from a plurality of LEDs (light emitting diodes) is irradiated forward by an optical member such as a reflector to form a predetermined light distribution pattern in the front. Are known.

  As this type of vehicle lamp, for example, in the one described in Patent Document 1, a reflector (reflecting surface) having a focal line (focal axis) along the left-right direction, and a plurality of LEDs arranged on the focal line of the reflector And the light emitted from the plurality of LEDs is reflected forward by the reflector to form a long light distribution pattern on the left and right. In such a vehicular lamp, the end of each LED that emits light to the cut-off line is placed on the focal line of the reflector so that a cut-off line (bright / dark boundary line) at the upper end of the light distribution pattern is clearly formed. It is matched.

Japanese Patent No. 4633635

  By the way, as LED used for a vehicle lamp, what emits white light by a semiconductor light emitting element and a phosphor is widely known. In such an LED, by irradiating the phosphor with blue excitation light from the semiconductor light emitting element, the yellow light emitted when the phosphor is excited and the excitation light are mixed (colored) so that white light is obtained. It has become.

  However, in the LED as described above, the degree of color mixture of excitation light (blue light) and yellow light changes according to the optical path length in the phosphor, and therefore, out of the excitation light emitted radially from the semiconductor light emitting element. The larger the emission angle from the optical axis that goes straight to the phosphor, the longer the optical path length in the phosphor, and thus the yellowish white light. That is, yellowish white light is emitted from the end of the LED.

  Therefore, when such an LED is used in the above conventional vehicle lamp, yellowish white light emitted from each end of the plurality of LEDs is superimposed to form a light distribution pattern cut-off line. As a result, the cut-off line becomes yellowish, and an undesirable light distribution pattern with color unevenness is formed. As a measure for suppressing such color unevenness, it is conceivable to block light from the end portion of each LED by a light blocking member or the like. In this case, however, a decrease in luminous flux utilization factor or addition of a light blocking member is involved. New problems such as higher costs arise.

  This invention is made | formed in view of the said situation, and makes it a subject to provide the vehicle lamp which can suppress the color nonuniformity of a light distribution pattern, without light-shielding the light from the edge part of LED.

In order to solve the above problems, the present invention provides:
A plurality of LEDs arranged to emit white light, which is a mixture of blue light from a semiconductor light emitting element and yellow light from a phosphor excited by the blue light, and arranged substantially along the left-right direction;
An optical member that has a focal line substantially along the left-right direction and is opposed to the light emitting surfaces of the plurality of LEDs, and irradiates the white light emitted from the plurality of LEDs forward,
In a vehicular lamp that forms a predetermined light distribution pattern ahead,
The plurality of LEDs are each composed of a first LED and a second LED having a lower luminance than the first LED, with each light emitting surface facing in a light emitting direction orthogonal to the left-right direction,
The first LED has one end that emits white light emitted to the upper end of the light distribution pattern by the optical member among both ends of the light emitting surface in a right and left direction and a direction orthogonal to the light emitting direction. It almost matches on the focal line,
Said 2nd LED has located the part inside the both ends of the said orthogonal direction among the light emission surfaces on the said focal line.

  According to the present invention, among the plurality of LEDs, white light from the first LED having higher luminance than the second LED is irradiated forward by the optical member (for example, a reflector) to form a high luminous intensity light distribution pattern. On the other hand, white light from the second LED having a lower luminance than the first LED is similarly irradiated to form a light distribution pattern with a low luminous intensity. At this time, since one end of the light emitting surface of the first LED that irradiates white light on the upper end of the light distribution pattern is substantially coincident with the focal line of the optical member, light is distributed by the white light emitted from one end of the light emitting surface. A clear cut-off line is formed at the upper end of the pattern, and the portion of the light emitting surface of the second LED that is on the inner side of both ends in the orthogonal direction orthogonal to both the left and right directions and the light emitting direction is located on the focal line. Therefore, the low luminous intensity light distribution pattern by the light from the second LED is formed above the high luminous intensity light distribution pattern while straddling the cut-off line of the high luminous intensity light distribution pattern by the light from the first LED. Is done.

As a result, compared to the conventional case where the ends of the light emitting surfaces of all the LEDs are aligned on the focal line, the light emitted from one end of the second LED is equivalent to the second LED in which one end of the light emitting surface is shifted from the focal line. Therefore, the yellowish white light is not irradiated on the cut-off line, so that the yellowing of the cut-off line can be reduced.
At the same time, since the second LED has the inner part of the light emitting surface positioned on the focal line, white light that is more bluish than that from one end of the light emitting surface is irradiated to the cut-off line. The yellowish white light from one end of the light emitting surface is offset by the bluish white light from the second LED, and the yellowing of the cut-off line can be further reduced.
Therefore, the color unevenness of the light distribution pattern can be suppressed without blocking the light from the end portion of the LED.

It is a perspective view of the vehicular lamp in a first embodiment. It is a top view of the vehicular lamp in a first embodiment. It is a longitudinal cross-sectional view of the vehicle lamp in 1st embodiment. It is a figure which shows the light distribution pattern which the vehicle lamp in 1st and 2nd embodiment forms on the front virtual screen. It is a figure which shows the light distribution pattern formed when the distance of the one end of the light emission surface of 2nd LED, and a focal line is larger than half of light emission surface length. It is a perspective view of the vehicle lamp in 2nd embodiment. It is a front view of several LED in 2nd embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the following description, the descriptions “front”, “rear”, “left”, “right”, “upper”, and “lower” refer to directions viewed from the vehicle lamp in each embodiment unless otherwise specified. Shall.

[First embodiment]
First, the vehicular lamp 1 according to the first embodiment of the present invention will be described.
1 to 3 are a perspective view, a plan view, and a longitudinal sectional view (a sectional view perpendicular to the left-right direction) of the vehicular lamp 1.
As shown in these drawings, the vehicular lamp 1 is a front fog lamp (front fog lamp) that is mounted on a front portion of a vehicle (not shown) and forms a light distribution pattern P (see FIG. 4) in front. LEDs (light emitting diodes) 10,... And a reflector 11.

  The plurality of LEDs 10,... Are arranged at equal intervals substantially along the left-right direction with each light emitting surface 10a facing downward. Each LED 10 is a conventionally known LED that emits white light from the light emitting surface 10a by a semiconductor light emitting element and a phosphor (not shown) disposed on the front surface of the semiconductor light emitting element. In the LED 10, blue light is emitted as excitation light of the phosphor from the semiconductor light emitting element, and the blue light excites a phosphor made of, for example, YAG (Y3Al5O12: Ce3 +) to emit yellow light from the phosphor. As a result, the blue light and the yellow light are mixed (colored) and white light is emitted. At this time, since the blue light from the semiconductor light emitting element has a longer optical path length in the phosphor and mixing with the yellow light is promoted, the portion closer to the end from the light emitting surface 10a of each LED 10 is more Yellowish white light is emitted.

Further, the plurality of LEDs 10,... Mainly include a plurality of first LEDs 101,... That form the light distribution pattern P, and one second LED 102 for suppressing color unevenness of the light distribution pattern P.
Among these, the plurality of first LEDs 101,... Are the remaining LEDs 10,... Excluding one second LED 102 from the plurality of LEDs 10,..., And are in a predetermined state with respect to the first reflecting surface 12a of the reflector 11 to be described later. Is arranged. Specifically, the plurality of first LEDs 101,... Are arranged in a state in which the front ends of the respective light emitting surfaces 101a are substantially aligned on a later-described focal line FL substantially along the left-right direction of the first reflecting surface 12a. Yes.

  On the other hand, the second LED 102 is any one of the plurality of LEDs 10..., And in the present embodiment, the second LED 102 is substantially at the center of the plurality of LEDs 10. The second LED 102 is disposed such that the front end of the light emitting surface 102a is positioned in front of the focal line FL, and the inner part of the light emitting surface 102a is positioned on the focal line FL. Yes. At this time, the distance L between the front end of the light emitting surface 102a and the focal line FL is preferably smaller than half the light emitting surface length W of the light emitting surface 102a along the front-rear direction, as will be described later.

  Note that at least one of the first LED 101 and the second LED 102 may be provided, and each quantity is not particularly limited. However, since the first LED 101 mainly forms the light distribution pattern P, the luminance (total luminance in the case of a plurality of LEDs) must be higher than that of the second LED 102 and is 1.5 times or more. It is more preferable to be high. Therefore, in the case where the first LED 101 and the second LED 102 are of the same type that emits light with the same luminance, the number of the first LED 101 only needs to be larger than the number of the second LED 102, and the number is 1.5 times or more. More preferably.

  The reflector 11 is an optical member that reflects the white light emitted downward from the plurality of LEDs 10... To the front, and is disposed below the plurality of LEDs 10. The reflector 11 has a curved plate-like curved plate portion 12 that opens obliquely upward in the front direction, and two side plate portions 13 and 13 that are erected on both left and right ends of the curved plate portion 12.

  The curved plate portion 12 is positioned below the plurality of LEDs 10 while the upper and lower positions of the upper ends thereof are substantially coincident with the light emitting surfaces 10a of the plurality of LEDs 10,. It faces each light emitting surface 10a of the LEDs 10,. And this opening inner surface becomes the 1st reflective surface 12a which reflects the white light radiate | emitted from several LED10 ... forward. The first reflecting surface 12a is formed in a parabolic columnar shape whose vertical cross-sectional shape is uniform in the left-right direction, and has a focal line FL substantially along the left-right direction. As described above, the focal line FL passes through the light emitting surfaces 10a of the plurality of LEDs 10,.

  The two side plate portions 13 and 13 are formed in a substantially fan shape in a side view in which the upper end and the front end coincide with the curved plate portion 12, and are erected so as to be orthogonal to the left-right direction. The inner side surface (side surface inside the lamp) of each side plate portion 13 is a second reflection surface 13a that reflects the white light emitted from the plurality of LEDs 10, ... toward the first reflection surface 12a.

Then, the formation aspect of the light distribution pattern P by the vehicle lamp 1 is demonstrated.
FIG. 4 is a diagram showing a light distribution pattern P formed on the virtual screen in front of the lamp.

  In the vehicular lamp 1, when the plurality of LEDs 10, emit light, white light emitted downward from the plurality of LEDs 10,... Is reflected forward by the first reflecting surface 12 a and the second reflecting surface 13 a of the reflector 11. The More specifically, the white light emitted downward from the plurality of LEDs 10,... Has a parabolic columnar shape having a focal line FL along the left-right direction directly or indirectly via the second reflecting surface 13a. Reflected forward by the one reflecting surface 12a. Therefore, this reflected light is irradiated forward while being diffused widely in the left-right direction, and forms a long light distribution pattern P in the left-right direction, as shown in FIG.

  At this time, white light emitted from the plurality of first LEDs 101,... Of the plurality of LEDs 10,... Forms the first light distribution pattern P1, and the white light emitted from the remaining one second LED 102 is the second. By forming the light distribution pattern P2, the light distribution pattern P is formed as a superposition of these two light distribution patterns P1 and P2.

  In the first light distribution pattern P1, the plurality of first LEDs 101 for forming the first light distribution pattern P1 has higher luminance than the second LEDs 102 for forming the second light distribution pattern P2. The light distribution pattern P is formed with a higher luminous intensity than the second light distribution pattern P <b> 2. Further, since the plurality of first LEDs 101,... Have the front ends of the respective light emitting surfaces 101a substantially coincident with the focal line FL of the first reflecting surface 12a, white light emitted from the front ends is reflected by the first reflecting surface 12a. As a result of irradiating the upper end of the first light distribution pattern P1 while being strongly condensed, a clear cut-off line (bright / dark boundary line) CL is formed at the upper end of the first light distribution pattern P1, that is, the upper end of the light distribution pattern P. It is formed.

  On the other hand, the second light distribution pattern P2 is formed with a lower luminous intensity than the first light distribution pattern P1 because the second LED 102 has lower brightness than the plurality of first LEDs 101,. No contours. In addition, since the second LED 102 has a portion of the light emitting surface 102a inside the front and rear ends positioned on the focal line FL, the second light distribution pattern P2 extends across the cut-off line CL. It is formed above P1.

Thereby, compared with the case where the front ends of the respective light emitting surfaces 10a of all the LEDs 10,... Are made coincident with the focal line FL, the second LEDs 102 are displaced by the amount of the second LED 102 whose front end is shifted from the focal line FL. The yellowish white light emitted from the front end is not irradiated on the cut-off line CL, so that the yellowing of the cut-off line CL is faded.
At the same time, since the second LED 102 has an inner portion of the light emitting surface 102a positioned on the focal line FL, white light that is more bluish than that from the front end of the light emitting surface 102a is irradiated to the cut-off line CL. The yellowish white light from the front end of each light emitting surface 101a of the plurality of first LEDs 101,... Is offset by the bluish white light from the second LED 102, and the yellow of the cut-off line CL is further reduced. The shining will fade.

  Here, in forming the second light distribution pattern P2, the distance L between the front end of the light emitting surface 102a of the second LED 102 and the focal line FL, that is, the second LED 102 is moved to the front side of the plurality of first LEDs 101,. The amount of movement is preferably smaller than half of the light emitting surface length W of the light emitting surface 102a along the front-rear direction. When this distance L is larger than half of the light emitting surface length W, as shown in FIG. 5, the second light distribution pattern P2 moves upwardly more than the first light distribution pattern P1, and the center of the light emitting surface 102a. The strong light emitted from the laser beam is irradiated above the cut-off line CL, and the light distribution pattern P may not satisfy the luminous intensity requirements of various standards.

As described above, according to the vehicular lamp 1 of the first embodiment, the front end of the light emitting surface 102a is on the focal line FL, as compared with the conventional case where the ends of the light emitting surfaces of all LEDs are aligned on the focal line. Since the yellowish white light emitted from the front end of the second LED 102 is not irradiated to the cut-off line CL by the amount shifted from the second LED 102, the yellowing of the cut-off line CL can be reduced.
At the same time, since the second LED 102 positions the inner part of the light emitting surface 102a on the focal line FL, white light that is more bluish than that from the front end of the light emitting surface 102a is irradiated to the cut-off line CL. Therefore, the yellowish white light from the front end of each light emitting surface 101a of the plurality of first LEDs 101,... Is offset by the bluish white light from the second LED 102, and the cut-off line CL is further reduced. Can reduce yellowing.
Therefore, the color unevenness of the light distribution pattern P can be suppressed without blocking the light from the end portion of the LED 10.

[Second Embodiment]
Then, the vehicle lamp 2 in 2nd embodiment of this invention is demonstrated.
6 is a perspective view of the vehicular lamp 2, and FIG. 7 is a front view of the plurality of LEDs 20,.
As shown in these drawings, the vehicular lamp 2 is a front fog lamp similar to the vehicular lamp 1 in the first embodiment, and includes a plurality of LEDs 20... And a projection lens 21.

The plurality of LEDs 20,... Are arranged at equal intervals substantially along the left-right direction with each light emitting surface 20a facing forward. Each LED 20 is configured similarly to the LED 10 in the first embodiment, and emits white light from the light emitting surface 20a.
Further, the plurality of LEDs 20,... Are configured by a plurality of first LEDs 201,... And one second LED 202, similarly to the plurality of LEDs 10,.

Among these, the plurality of first LEDs 201,... Are arranged in a state in which the lower ends of the respective light emitting surfaces 201a are substantially aligned on a later-described focal line FL2 substantially along the left-right direction of the projection lens 21.
On the other hand, the second LED 202 is arranged such that the lower end of the light emitting surface 202a is positioned below the focal line FL2, and the inner portion of the light emitting surface 202a is positioned on the focal line FL2 from the upper and lower ends. Has been. At this time, the distance L2 between the lower end of the light emitting surface 202a and the focal line FL2 is more than half the light emitting surface length W2 of the light emitting surface 202a along the vertical direction, like the distance L in the first embodiment. It is preferable that it is small.
The first LED 201 and the second LED 202 are configured in the same manner as the first LED 101 and the second LED 102 in the first embodiment with respect to the other points. It is the same.

  The projection lens 21 is an optical member that projects the white light emitted from the plurality of LEDs 20,... Upside down and is disposed in front of the plurality of LEDs 20,. This projection lens 21 is an aspherical plano-convex lens having a rear surface (incident surface) as a flat surface and a front surface (outgoing surface) as a convex surface, and has a vertical cross-sectional shape that is uniform in the left-right direction. A focal line FL2 substantially along the direction is provided on the rear side. As described above, the focal line FL2 passes through the light emitting surfaces 20a of the plurality of LEDs 20,.

  Also with the above vehicle lamp 2, the same effect as the vehicle lamp 1 in the first embodiment can be obtained.

  The embodiments to which the present invention can be applied are not limited to the first and second embodiments described above, and can be appropriately changed without departing from the spirit of the present invention.

  For example, in each of the embodiments described above, the vehicular lamps 1 and 2 that are front fog lamps have been described as examples of the vehicular lamp according to the present invention. However, the present invention forms a light distribution pattern having a cut-off line. If it is a vehicle lamp, it can apply suitably also to vehicle lamps other than fog lamps, such as a headlamp which forms a low beam, for example.

In the first embodiment, the light emitting surfaces 10a of the plurality of LEDs 10,... Are directed downward, but the direction (light emission direction) of the light emitting surface 10a is that of the plurality of LEDs 10,. What is necessary is just to be orthogonal to the arrangement | sequence direction (left-right direction), and upper direction, diagonally downward, etc. may be sufficient.
However, it is needless to say that the arrangement of the reflector 11 and the like need to correspond to this light emission direction. Further, according to this light emitting direction, the light emitting surface 101a of each first LED 101 distributes light by the reflector 11 out of both ends in the orthogonal direction orthogonal to both the arrangement direction (left and right direction) of the plurality of LEDs 10,. One end that emits the white light irradiated to the upper end of the pattern P needs to be substantially coincident with the focal line FL, and the second LED 102 is a part of the light emitting surface 102a that is inside the both ends in the orthogonal direction. Must be positioned on the focal line FL.
The above points are the same for the plurality of LEDs 20 in the second embodiment.

1,2 Vehicle lamp 10,20 LED
10a, 20a Light emitting surface (LED light emitting surface)
101,201 1st LED
101a, 201a Light emitting surface (light emitting surface of the first LED)
102,202 Second LED
102a, 202a Light emitting surface (light emitting surface of the second LED)
11 Reflector (Optical member)
12a First reflective surface FL Focal line 21 Projection lens (optical member)
FL2 Focal line P Light distribution pattern P1 First light distribution pattern P2 Second light distribution pattern CL Cut-off line L, L2 distance (distance between one end of light emitting surface of second LED and focal line)
W, W2 Light emitting surface length

Claims (5)

A plurality of LEDs arranged to emit white light, which is a mixture of blue light from a semiconductor light emitting element and yellow light from a phosphor excited by the blue light, and arranged substantially along the left-right direction;
An optical member that has a focal line substantially along the left-right direction and is opposed to the light emitting surfaces of the plurality of LEDs, and irradiates the white light emitted from the plurality of LEDs forward,
In a vehicular lamp that forms a predetermined light distribution pattern ahead,
The plurality of LEDs are each composed of a first LED and a second LED having a lower luminance than the first LED, with each light emitting surface facing in a light emitting direction orthogonal to the left-right direction,
The first LED has one end that emits white light emitted to the upper end of the light distribution pattern by the optical member among both ends of the light emitting surface in a right and left direction and a direction orthogonal to the light emitting direction. It almost matches on the focal line,
Said 2nd LED has located the inner side part from the both ends of the said orthogonal direction among the light emission surfaces on the said focal line, The vehicle lamp characterized by the above-mentioned.   2. The vehicular lamp according to claim 1, wherein a distance between the one end of the light emitting surface and the focal line of the second LED is smaller than half of a length of the light emitting surface along the orthogonal direction. . At least one of the first LED and the second LED is provided,
The vehicular lamp according to claim 1 or 2, wherein the total luminance of the first LEDs is 1.5 times or more the total luminance of the second LEDs. The optical member is a reflector that reflects white light emitted from the plurality of LEDs forward,
The reflector has a parabolic columnar reflecting surface having the focal line,
The plurality of LEDs are:
Each light emitting surface faces upward or downward,
Among the plurality of LEDs, the first LED has the front end of the light emitting surface substantially coincident with the focal line, and the second LED has the front end of the light emitting surface positioned in front of the focal line. The vehicular lamp according to any one of claims 1 to 3. The optical member is a projection lens that has the focal line behind and is disposed in front of the plurality of LEDs, and projects the white light emitted from the plurality of LEDs to the front while being inverted up and down.
The plurality of LEDs are:
Each light emitting surface is facing forward,
Among the plurality of LEDs, the first LED has the lower end of the light emitting surface substantially coincident with the focal line, and the second LED has the lower end of the light emitting surface positioned below the focal line. The vehicular lamp according to any one of claims 1 to 3.

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