JP2002231013A - Light-emitting diode and lighting fixture for vehicle using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a required light distribution without the help of action of optical elements other than direct and reflective light, by an effective use of light of a light-emitting diode. SOLUTION: The light-emitting diode 1 provided with a chip for light emission 2 and a lens part 3 enveloping the chip 2, is further provided with a region for direct light 5 for emitting light from the chip 2 outside as direct light and a region for reflective light 6 for irradiating light from the chip 2 on a reflecting material 7 fitted outside after transmission through the lens 3. The region for direct light 5 is formed so as to have rotationally asymmetric shape around the light axis of the element. Also, either a peripheral part of the region for direct light 5 or a side face of the lens part 3 is utilized as the region for reflective light 6, which is so formed as to have a rotational symmetry around the light axis of the element. Further, a design is to be possible on a required light distribution without relying on refraction of a lens step, in the case of a lighting fixture for a vehicle use with a plurality of light source units arrayed including the light-emitting diode 1 and the reflecting material 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting diode in which the function of a lens portion is divided into a direct light and a reflected light so that light distribution can be easily controlled, and a vehicle using a plurality of the light emitting diodes as a light source. Lighting equipment.

[0002]

2. Description of the Related Art Among light emitting devices, a light emitting diode and an LED (Light Emitting Diode) are known.
e) is used for various display devices because it has a higher luminous flux and is advantageous in terms of longer life, lower power consumption, lower calorific value, and the like than conventional light sources such as incandescent lamps. For example, examples of application to a vehicle lamp include a high-mount stop lamp, a side marker lamp, and a tail stop lamp provided as measures for preventing a rear-end collision of a following vehicle.

The light emitting diode has a semiconductor chip (light emitting chip) inside, and the chip is protected by a transparent resin lens portion. The distal end of the lens unit has a shape such as a spherical surface having rotational symmetry around the optical axis. As a result, the luminous intensity distribution of a single light emitting diode is a distribution close to a truncated cone, with a tendency that the luminous intensity is high in the central part near the optical axis and decreases as the distance from the optical axis to the peripheral part decreases.

[0004]

In a conventional lamp using a light emitting diode, a light distribution is designed using only the direct light of the light emitting diode. It is necessary to use a step (such as a fisheye lens step). That is, unless some lens element is provided in front of the light emitting diode, it is difficult to sufficiently utilize light contributing to a desired light distribution, and there is a problem that the appearance design is restricted by forming a lens step. Will occur.

It is important that the shape of the lens portion of the light emitting diode has symmetry around the optical axis. That is, in the conventional LED, the following inconvenience occurs due to the fact that the tip end shape of the lens portion is rotationally symmetric around the optical axis (a rotating body such as a spherical surface).

FIG. 13 schematically shows an isoluminous distribution diagram of a conventional LED, and shows a concentric pattern arrangement (isoluminous curve) due to the fact that the lens portion is a rotating body. Are almost concentric). Therefore, for example, with respect to the standard light distribution of the lamp, the width in the horizontal direction (see the line HH) is wider than the width in the vertical direction (see the line VV). (Refer to the range R indicated by the square frame.), Wasteful light is generated in the upper and lower portions, and this results in loss of light that does not conform to the light distribution standard. This light is due to the contribution of only light directly from the LED chip. Therefore, in order to use light efficiently, in the conventional configuration, a lens step (eg, a fisheye lens step) disposed in front of the LED plays an important role in controlling light distribution, but is disadvantageous in terms of cost. Also, there are problems such as design restrictions.

Accordingly, an object of the present invention is to obtain a desired light distribution without using the effects of optical elements other than direct light and reflection by efficiently utilizing the light of a light emitting diode. And

[0008]

In order to solve the above-mentioned problems, a light emitting diode according to the present invention comprises a light emitting chip and a lens portion including the chip. It has the area shown.

A direct light region for directly irradiating the light emitted from the chip directly to the outside as direct light; and transmitting the light emitted from the chip to a reflection member provided outside after passing through the lens portion. Area for reflected light to irradiate.

The tip of the lens portion is used as a region for direct light, the region is formed so as to have a non-rotationally symmetric shape around the optical axis of the element, and the peripheral portion of the region for direct light or The side surface of the lens portion is used as a region for reflected light, and the region is formed so as to have a rotationally symmetrical shape around the optical axis of the element.

Further, in the vehicular lamp according to the present invention, a plurality of light emitting diodes having such a structure are arranged on a supporting member to form a light source group, and each light emitting diode has a reflection surrounding the light emitting diode. A vehicle lamp having a configuration in which mirrors are arranged respectively, wherein light emitted from a light emitting diode chip is emitted to the outside through a direct light area of a lens unit, and emitted from the chip to form a reflected light area. The transmitted light is applied to a reflecting mirror arranged for the light emitting diode to be reflected.

Therefore, according to the present invention, with respect to the light control of the light-emitting diode, the light is directly irradiated to the outside of the lens portion through the direct light region, and after passing through the reflected light region,
The light reflected by the reflecting member (or the reflecting mirror) can be separated from each other, and each light can be effectively used for each purpose with respect to the contribution to the light distribution.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory diagram showing a basic structure of a light emitting diode according to the present invention.

A light emitting diode (hereinafter, referred to as “LED”) 1 includes a (semiconductor) chip 2 for emitting light, and a lens unit (or a sealing lens) 3 containing the chip.

The lens portion 3 is formed using a colorless or colored transparent resin material. As shown in the figure, a portion 4 (upper side in the figure) ahead of the light emitting surface of the chip 2 is formed as shown in FIG.
Are divided into two areas (the numbers in parentheses indicate symbols), and different functions are given to each area.

A region for direct light (5) a region for reflected light (6).

The "LL" line shown in the figure indicates the optical axis of the LED element.

The direct light area 5 occupies a predetermined angular range (indicated by "α" in the figure) at a position close to the optical axis. The main area 5 is an area for directly emitting light emitted from the chip 2 to the outside of the lens unit 3 and irradiating the light as direct light (light that is not reflected light outside the element).

On the other hand, the reflected light area 6 occupies a predetermined angular range (indicated by “β” in the figure) adjacent to the periphery of the direct light area 5 as shown in the figure, or the lens section 3. Is defined in a range straddling the side surface portion of. In this region, it is necessary to irradiate the light emitted from the chip 2 to the reflecting member 7 (a member constituting a reflecting mirror) provided outside the LED 1 after passing through the lens unit 3. Is done. That is, the light emitted from the main area 6 to the outside of the lens unit 3 is once reflected by the reflection surface 8 formed on the reflection member 7 and then irradiated forward (in the irradiation direction).

By the way, as described with reference to FIG.
If the lens part of D has a simple rotationally symmetrical shape, make full use of the optical action of the lens step, and correct the light that would otherwise be wasted by the refraction action of the lens step, as effectively as possible. Although it is necessary to use it, there is a problem that light is lost even when light passes through the lens step, or there is a problem of cost for forming the lens step, and the lens step is formed. There are restrictions on the design due to the inability to use an outer lens or the like (the interior of the lamp cannot be seen because it is transparent).

Therefore, in order to avoid these inconveniences, in the present invention, the tip of the lens portion is used as a region for direct light, and the shape of the region is determined by using an LED.
It is formed so as to be non-rotationally symmetric around the optical axis of the element. For example, assuming a plane perpendicular to the optical axis of the LED element, the shape of the direct light area viewed from the direction along the optical axis is not circular, and May be designed so that the width along one axis (first axis) corresponding to the width is wider than the width along the other axis (second axis) corresponding to the vertical direction (for example, An ellipse having the first axis as the major axis and the second axis as the minor axis, a polygon having a long angle in the first axis direction, and an angled polygon.)

The reflected light region 6 including the periphery of the direct light region 5 or the side surface of the lens portion is formed in a rotationally symmetrical shape (cylindrical, conical, etc.) around the optical axis of the LED element. Is preferred. The reasons include that the lens portion is easy to make and that the light control on the reflection surface is not complicated.

As for the direct light region 5 and the reflected light region 6, there are a method of forming both with the same resin material and a method of forming both with materials having different optical characteristics. The former is preferred from the viewpoint of easiness. Then, there are a method of dividing the two as a divided region so that the step is visually clear, and a method of forming both regions continuously so as to be continuous without any step. Considering the above, the latter is more preferable.

In order to constitute a lamp using such LEDs, a plurality of LEDs 1, 1,... Are arranged on a support member to form a light source group, and a light source group is formed. The reflecting mirrors surrounding this are arranged respectively. Note that the lens portion 3 of each LED is located in the direct light region 5.
For example, as shown in FIG. 2, the light emitted from the chip 2 of the LED 1 is directly emitted to the outside through the direct light area 5 and emitted from the chip 2 as shown in FIG. After that, the light that has passed through the reflected light area 6 is irradiated onto a reflecting mirror arranged for the LED 1 and reflected.

FIGS. 3 and 4 are diagrams for explaining an example of the light distribution design.

FIG. 3 shows the luminous intensity distribution (design target) of the lamp in comparison with the standard, and the horizontal axis indicates the irradiation position (indicated by the irradiation angle) in the vertical or horizontal direction of the light distribution pattern. Tori (the right direction of the axis is "UP" (upward) or "R"
IGHT ”(right), and the left direction of the axis is in the opposite direction, ie,“ DOWN ”(down) or“ LEFT ”.
(Left) are shown. ), And the ordinate represents the light intensity axis CD to show the characteristics.

In the drawing, a solid line TG indicates a target light distribution characteristic, and a dashed line ST indicates a line ST.
Indicates the characteristics defined by the standard. Note that the graph line ST has a substantially trapezoidal shape at the center of the peak, and has a shape in which the foot portion is slightly widened to the left and right. The graph line TG is located outside the graph line ST so as to include the graph line ST. (However, the part near the peak has a rounded shape.) And
Each of the graph lines has a symmetrical shape with respect to the luminous intensity CD.

In the figure, a portion surrounded by a circle A is an LED.
1 is obtained as the contribution of the direct light, and the portion surrounded by a circle B above it is obtained as the contribution of the reflected light by the LED 1 and the reflection member 7. As can be seen from the figure, the reflected light mainly contributes to the central portion having a high luminous intensity, and the direct light contributes to the foot portion thereof.

FIG. 4 shows the luminous intensity distribution (design target) of only the reflected light, and the setting of the vertical and horizontal axes is the same as in FIG.

As shown by a graph line 9, the light distribution characteristic has a substantially trapezoidal shape, and the diffusion angle is narrower than the direct light contribution range (the foot portion in FIG. 3). By performing a simulation including ray tracing or the like so as to obtain a distribution close to the characteristic, the shape of the reflection surface 8 is finally determined.

As described above, a desired light distribution can be obtained by efficiently combining the direct light from the LED and the light reflected by the reflecting member.

Then, a transparent lens member having no lens step or a lens member having almost no lens action can be used as the outermost member in the lamp. In other words, since such a lens member is arranged in front of the LED and the reflecting mirror, the direct light from the LED and the reflected light from the reflecting mirror can be emitted outside the lamp through the lens member. Eliminates the effects of dimming at the lens step (for example,
Since only a smaller number of LEDs need to be used, it is advantageous in terms of cost. ) And design constraints are eliminated (the interior of the lamp becomes visible, etc.).

[0033]

5 to 12 show an embodiment of the present invention, and show an example in which the present invention is applied to an automotive lamp (a tail stop lamp or the like).

FIG. 5 schematically shows the front shape of the lamp 10. The lamp space defined by a lens member 11 formed of a transparent material (such as synthetic resin or glass) and a lamp body 12. Inside, a first lamp unit 13,
A second ramp section 14 is provided.

The first lamp section 13 functions as, for example, a stop lamp, and includes a light source group using a large number of LEDs 15, 15,... And reflecting mirrors 16, 16 provided for each of these LEDs. (In FIG. 5, the LED and the reflecting mirror are shown by broken lines for convenience of illustration, but these are visible from the lens member 11 in a transparent state.) In this example, three irradiation units 17, 17, 17 in which six light source units each including the LED 15 and the reflecting mirror 16 are arranged in a horizontal row are arranged in the vertical direction.

FIG. 6 is a sectional view of the first lamp portion 13 when the lamp 10 is cut along the longitudinal direction (horizontal direction), and FIG. 7 is a direction perpendicular to the direction (vertical direction). (Direction).

As shown, the first ramp section 13
A support member (base member) 18 formed in a step shape using a synthetic resin material, and a reflector member 19 that supports a lens portion of each LED and has a reflecting mirror 16 formed on the LED 15 are provided.

Each of the steps of the support member 18 is provided with a holder 20, 20,... So that individual LEDs can be arranged on those flat places. When the lead (outer lead) is fitted, electrical connection with a wiring member (not shown) is made.

The reflector member 19 includes reflecting mirrors 16 and 1
Are provided, and the lens portions of the respective LEDs are inserted through light source disposing holes respectively formed in the central portions of the respective reflecting mirrors. Each reflecting mirror is formed with a reflecting surface (having a rotationally symmetric shape around the optical axis) by vapor deposition of aluminum, and LE is formed.
The function of reflecting the light emitted from the lens portion of D15 toward the irradiation direction of the lamp 10 is provided.

The members 21, 21 and 21 (FIGS. 5 and 6) provided at positions adjacent to the reflector member 19 are provided.
reference. ) Is a retroreflector.

When positioning the reflector member 19 with respect to the support member 18, for example, as shown in FIG. 7, a positioning portion 22 projecting from the reflector member 19 to the support member 18 is supported by the support member 18. Hole 23
, So that they can be adjusted so as to have a predetermined positional relationship.

In a portion of the lens member 11 constituting the first lamp portion 13, that is, an inner surface region corresponding to the LED 15 and the reflecting mirror 16, no lens step is formed at all, and the lens member 11 is in a transparent state. Therefore, the lens portion of each LED 15 and the surface of the reflector member 19 can be seen from the outside of the lamp.

As shown in FIG. 7, the second lamp section 14 includes an incandescent lamp 24 as a light source, a reflecting mirror 25 and an inner lens 26, and functions as, for example, a turn signal lamp. In the lens member 11, a portion corresponding to the lamp portion 14 is provided with a lens 27 on which a number of lens steps (not shown) are formed, and the lens 27 is provided outside the inner lens 26. It is a configuration that is arranged.

FIGS. 8 to 11 show examples of the structure of the LED element.

The LED 15 has a lens portion 28 made of a sealing resin such as an epoxy resin, and has two leads 29 and 29. Note that, of these leads, the portion covered with the sealing resin is the inner lead 29a.
And the portion protruding to the outside is the outer lead 29b.
It is. A chip (not shown) is arranged in a concave portion formed in the cathode-side inner lead, and the chip is connected to the anode-side inner lead by wire bonding.

In the lens portion 28, the tip portion 2
8A is the above-mentioned area for direct light, and as shown in FIG. 9, the shape of the element viewed from the optical axis direction is elliptical.
In this example, the major axis of the ellipse corresponds to the left-right direction of the lamp 10,
The short axis of the ellipse corresponds to the up and down direction of the lamp 10, and LE
Such a positional relationship is obtained when D15 is attached to the holder 20.

As shown in FIG. 8, this direct light region has an elliptical cross-sectional shape on a plane including the axis extending vertically and the optical axis (of the lamp). As shown, the cross-sectional shape in a plane including the axis extending in the left-right direction (of the lamp) and the optical axis is circular (constant curvature). The focal position of the ellipse and the center position of the circle are set at a predetermined position in front of the chip or the like according to the positional relationship with the chip in the lens unit.

In the lens section 28, the direct light area 28A
Is used as a region for reflected light, and in this example, as shown in FIG. 9, it has a circular shape when viewed from the optical axis direction of the element. Then, the cross-sectional shape in a plane including the axis extending in the vertical direction or the horizontal direction (of the lamp) and the optical axis is circular (constant curvature), and has a shape having rotational symmetry about the optical axis. Light emitted from the LED chip and emitted to the outside of the lens unit 28 through the reflected light area 28B reaches the reflecting surface of the reflecting mirror 16 and is reflected.

The outer shape of the lens portion 28 excluding these regions has a cylindrical shape, but has nothing to do with the optical action on light from the chip. Further, in this example, a step is generated between the direct light region 28A and the reflected light region 28B, but it is also possible to design such that both are continuously connected on the outer surface of the lens portion 28. .

The outer lead 29b of the LED element is made of a conductive material having appropriate elasticity and high thermal conductivity (for example,
As shown in FIG. 11, a wide portion 29c is formed for each lead. In addition, a pair of circular holes 30, 30 is provided at a position near an end in the longitudinal direction in the portion, and a long hole 31 extending in the longitudinal direction is formed between them.

As shown in FIGS. 8 to 10, the long hole 31 is formed by connecting each outer lead 29b to the wide portion 29 thereof.
A slit is formed by bending the center of c into a U-shape, and a wiring member (not shown) is press-fitted into the slit to perform electrical connection and mechanical fixation of the lead. The circular hole 30 functions as a guide hole for preventing the outer lead 29b from being displaced during bending.

FIG. 12 schematically shows the equal luminous intensity distribution of the lamp 10, in which the horizontal axis indicates the horizontal direction (or horizontal direction) axis "HH" and the vertical axis indicates the vertical direction (or vertical direction). The shape and tendency of the isoluminance curve are shown along the axis “VV” of the direction (direction) (see FIGS. 3 and 4 for the design targets and standards of the luminous intensity distribution).

The horizontal, substantially elliptical isoluminous curves contributing to the luminous intensity distribution near the center are densely arranged at the center, and this portion "E" mainly indicates the contribution of the light distribution by the direct light of the LED 15. I have. A portion “F” where the density of the isoluminous curve is sparse around it indicates the contribution of the light distribution by the reflected light emitted from the LED 15 via the reflecting mirror 16.

As compared with the example shown in FIG. 13, it can be seen that the use efficiency of light is high because the useless light is reduced in the vertical direction. As described above, the shape of the direct light region 28A in the lens unit 28 is an elliptical shape that is long to the left and right as viewed from the optical axis direction of the element, and the range of direct light in the luminous intensity distribution conforms to the light distribution standard. Therefore, the distribution becomes long in the horizontal direction. The shape of the reflected light area 28B in the lens portion 28 is a rotating body around the optical axis, and the reflecting mirror 16 has rotational symmetry around the optical axis. It shows a concentric distribution in the range it carries. That is, the direct light region 28A and the reflected light region 28
The shape B is obtained as a result of performing light distribution design, simulation, and the like for each of the regions while distinguishing the functions of each region so as to obtain such a light distribution.

[0055]

According to the first aspect of the present invention, the light control of the light emitting diode is performed by directly irradiating the light to the outside of the lens portion through the direct light area and after passing through the reflected light area. , And the light reflected by the reflecting member (or the reflecting mirror) can be separated, and each light can be effectively used for the purpose of contributing to the light distribution, without the refraction effect of the lens step. A desired light distribution can be obtained. Further, it is possible to prevent a problem caused by the shape of the lens portion of the light emitting diode having rotational symmetry around the optical axis.

According to the second and third aspects of the present invention,
In a vehicular lamp using a plurality of light emitting diodes, the problem of the cost for forming the lens steps and the problem of the decrease in the amount of light are eliminated, and the design of the external appearance is not restricted by the formation of the lens steps.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a basic configuration of a light emitting diode according to the present invention.

FIG. 2 is a diagram for explaining light emitted from an LED.

FIG. 3 is a diagram showing a target light distribution and a standard of a vehicle lamp.

FIG. 4 is a diagram showing a target light distribution by reflected light.

FIG. 5 shows an embodiment of the present invention together with FIGS. 6 to 12, and is a schematic front view of a lamp.

FIG. 6 is a horizontal sectional view of a main part.

FIG. 7 is a vertical sectional view of a main part.

8 shows an example of the configuration of an LED together with FIGS. 9 to 11, and FIG. 8 is a side view.

FIG. 9 is a front view of the LED.

FIG. 10 is a side view seen from another direction.

FIG. 11 is a side view showing a state before bending the outer lead.

FIG. 12 is a diagram for explaining a light distribution of a lamp.

FIG. 13 is a diagram for explaining a conventional problem.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Light emitting diode, 2 ... Chip, 3 ... Lens part, 5 ...
Area for direct light, 6 area for reflected light, 7 reflecting member, 10
... Vehicle lamp, 11 ... Lens member, 15 ... Light emitting diode, 16 ... Reflector, 18 ... Support member, 19 ... Reflection member

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F21Q 1/00 FH (72) Inventor Tadayuki Okuda 500 Kitawaki, Shimizu City, Shizuoka Prefecture Koito Manufacturing Shizuoka Plant F term (reference) 3K080 AA01 AB01 BA04 BA07 BB01 BB20 BC02 BC11 BD01

Claims (3)

[Claims] 1. A light emitting diode comprising a light emitting chip and a lens portion enclosing the chip, wherein (a) the lens portion directly irradiates light emitted from the chip to the outside as direct light. And (b) directing the tip of the lens portion to directly irradiate a reflection region for irradiating light emitted from the chip through the lens portion to a reflection member provided outside after transmitting through the lens portion. Used as an area for light, the area being formed in a non-rotationally symmetrical shape around the optical axis of the element; A light emitting diode, wherein the region is formed in a rotationally symmetrical shape around the optical axis of the element. 2. A structure in which a plurality of light emitting diodes according to claim 1 are arranged on a support member to form a light source group, and a reflecting mirror surrounding each light emitting diode is arranged for each light emitting diode. The light emitted from the chip of the light emitting diode is directly emitted to the outside through the direct light region, and the light emitted from the chip and passed through the reflected light region is a light emitting diode. A vehicular lamp characterized in that the light is radiated to and reflected by the reflecting mirror arranged with respect to the vehicle. 3. The vehicular lamp according to claim 2, wherein a transparent lens member having no lens steps or a lens member having almost no lens action is provided in front of a light source group of light emitting diodes and a reflecting mirror. And vice versa, and wherein the direct light from each light emitting diode and the light reflected by the reflecting mirror are emitted out of the lamp through the lens member.