JP2010003597A - Led lighting unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an LED lighting unit capable of reducing its height for downsizing. <P>SOLUTION: The LED lighting unit 1 includes an light guide plate 2, an LED 3 disposed opposite to the light guide surface 2d of the light guide plate 2, and a reflecting plate 4 disposed at the side of the reflecting plane 2b of the light guide plate 2. Further, the unit 1 is equipped with a reflecting plane (a reflecting means) 2c in the guiding plate with the optical axis of the LED 3 disposed as conforming to the optically emitting direction from the light guide plate 2, for the purpose of reflecting the light from the LED 3 to the guiding plane 2 in the direction orthogonal to the optically exiting direction from the guiding plane 2. More specifically, a flexure 2A is formed at the end of the reflecting plane 2 as bent in the substantially orthogonal direction to the optically exiting direction 2a of the reflecting plane 2, to make the end surface of the flexure 2A serve as the light guide surface 2d. At the same time, the sloped reflecting plane 2c is formed at the corner of the flexure 2A. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an LED lamp unit that uses an LED disposed facing a light introduction surface of a light guide plate as a light source.

  An LED lamp unit that uses an LED as a light source is used, for example, as a vehicular lamp. The basic configuration of the LED lamp unit will be described with reference to FIGS. 8 and 9.

  8 is a front view of a conventional LED lamp unit, FIG. 9 is a cross-sectional view taken along the line CC of FIG. 8, and the LED lamp unit 101 shown in FIG. 8 is used as a vehicular lamp. A light guide plate 102 formed into a rectangular flat plate shape by a light-sensitive material, and a plurality (three in the illustrated example) arranged in parallel in the Y direction of FIG. 8 along the light introduction surface 102d of the light guide plate 102. LED 103, a reflection plate 104 disposed on the reflection surface 102 b (back surface) side of the light guide plate 102, and an outer lens 105 disposed on the emission surface 102 a side of the light guide plate 102.

  Here, as previously proposed by the present applicant in Japanese Patent Application No. 2007-021555, the upper end portion of the reflector 104 is formed with a bent portion 104B that is bent obliquely at a predetermined angle toward the light guide plate 102. The inner surface of the bent portion 104B facing the light guide plate 102 is a reflective surface 104b.

  In the LED lamp unit 101 configured as described above, emitted light emitted upward (Z direction) from each LED 103 is introduced into the light guide plate 102 from the light introduction surface 102 d at the lower end surface of the light guide plate 102. As shown in FIG. 9, a part of the light L1 ′ is emitted from the reflecting surface 102b of the light guide plate 102 to the outside, reaches the reflecting plate 104, and is reflected by the reflecting surface 104a of the flat plate portion 104A of the reflecting plate 104. After reentering the inside of the light guide plate 102, the light is emitted from the emission surface 102 a of the light guide plate 102 toward the front side in the horizontal direction (X direction) as irradiation light L ′. Further, another part of the light L2 ′ is reflected by the reflecting surface 102b of the light guide plate 102 and then emitted from the exit surface 102a of the light guide plate 102 toward the front in the horizontal direction (X direction) as the irradiation light L ′. The light L3 ′ reaching the upper end surface 102g of the optical plate 102 is emitted from the upper end surface 102g to the outside and reflected by the reflection surface 104b of the bent portion 104B formed at the upper end of the reflection plate 104 as irradiation light L ′. Irradiation toward the horizontal front (X direction). In this way, the light L3 ′ passing upward from the upper end surface 102g of the light guide plate 102 is reflected horizontally forward (X direction) by the reflection surface 104b of the bent portion 104B formed on the reflection plate 104 and used as the irradiation light L ′. Therefore, the light use efficiency is increased, and the illuminance and luminance of the vehicular lamp are increased.

By the way, in patent document 1, while providing a condensing body between LED and a light-guide plate, a linear Fresnel lens is provided in the side surface (surface which opposes the light introduction surface of a light-guide plate) of a light-condensing body, LED. A configuration has been proposed in which light emitted radially (V-shaped) is refracted by the action of a linear Fresnel lens to be converted into parallel light, and the parallel light is introduced from the light introduction surface of the light guide plate.
JP 2007-073469 A

In the LED lamp unit 101 shown in FIG. 8 and FIG. 9, the light emitted from each LED 103 and introduced into the light guide plate 102 is not uniform on the side close to the LED 103. As shown in FIG. 4, light is emitted radially (V-shaped), and uneven light is inevitably generated in that portion. Therefore, in order to uniformly illuminate the LED lamp unit 101, it is necessary to cover and hide the portion of the height H2 ′ where light unevenness occurs with a light shielding member, and the portion that is practically used as illumination has the height H2 ′. It is limited to the region of height H1 ′ excluding the part. In FIG. 1, the shaded area is the light emitting area.
In addition, since the LED 103 is disposed directly under the light guide plate 102, the total height H ′ of the LED lamp unit 101 becomes large, and when the LED lamp unit 101 is used as a vehicle lamp, the layout thereof is increased. There is a problem of being restricted.

  Even in the configuration proposed in Patent Document 1, since the light collector is interposed between the LED and the light guide plate, the same problem that the overall height increases and the unit increases in size occurs.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an LED lamp unit that can be miniaturized while keeping the height dimension low.

  In order to achieve the above object, an invention according to claim 1 is directed to a light guide plate, an LED disposed opposite to a light introduction surface of the light guide plate, and a reflector disposed on a reflective surface side of the light guide plate. In the LED lamp unit comprising: the LED is arranged so that the optical axis thereof coincides with the light emission direction from the light guide plate, and the light introduced from the LED to the light guide plate is emitted from the light guide plate The light guide plate is provided with reflecting means for reflecting in a direction orthogonal to the light guide plate.

  According to a second aspect of the present invention, in the first aspect of the present invention, a bent portion that is bent at a substantially right angle with respect to an exit surface of the light guide plate is formed at an end portion of the light guide plate, and the end surface of the bent portion is formed. In addition to the light introduction surface, the inclined reflection surface is formed at the corner of the bent portion.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, a bent portion that is bent obliquely in the optical axis direction of the LED is formed at an end of the reflector, and the bent portion At least the surface facing the light guide plate is a reflection surface.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, a plurality of light diffusion patterns having the same shape are formed on the reflective surface of the light guide plate on the side facing the reflective plate. The density of the light diffusion pattern is gradually increased along the light introduction direction to the light plate, the size is gradually increased, the depth is gradually increased, or a combination thereof. It is characterized by.

  The invention according to claim 5 is the invention according to claim 4, characterized in that the diffusion pattern is formed into a round or polygonal concave or convex by embossing, painting, printing or dot processing.

  According to invention of Claim 1 and 2, while arrange | positioning LED so that the optical axis may correspond with the light-projection direction from a light-guide plate, the light of LED introduced in the light-guide plate from the light introduction surface of the light-guide plate Is provided in a direction orthogonal to the light emission direction from the light guide plate, so that radial (V-shaped) light emission due to the characteristics of the LED is made before the light reaches the reflection surface and reflected by the reflection means The light becomes uniform light without unevenness. As a result, uniform irradiation light with no unevenness is emitted from the exit surface of the light guide plate, and the entire exit surface of the light guide plate can be used practically as illumination. Further, since the LED can be arranged beside the light guide plate so as to overlap the light guide plate in the height direction, not directly under the light guide plate, an extra height space is not required for installing the LED.

  As a result of the above, in the LED lamp unit according to the present invention, the overall height can be shortened by the height of the region where the light unevenness occurs in the conventional LED lamp unit, and the whole is made compact and compact accordingly. Can be configured.

  According to the third aspect of the present invention, the light that is emitted from the end face of the light guide plate can be reflected by the reflection surface of the bent portion formed on the reflection plate and used as irradiation light. It is done.

  According to invention of Claim 4 and 5, since the light introduce | transduced into the inside of the light-guide plate from LED is spread | diffused by the light-diffusion pattern formed in the reflective surface facing the reflective plate of a light-guide plate, it is a reflective surface. The light reflected by the light is diffused and uniformed by the light diffusion pattern, and illumination without unevenness in brightness becomes possible. Then, gradually increase the arrangement density of the light diffusion pattern along the light introduction direction to the light guide plate, gradually increase the size, gradually increase the depth, or a combination thereof. Therefore, the irradiation light emitted from the exit surface of the light guide plate is made more uniform in the light introduction direction to the light guide plate, and uniform illumination without unevenness of brightness is possible in the light introduction direction to the light guide plate.

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

  1 is a front view of an LED lamp unit according to the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, FIG. 3 is a sectional view taken along line BB in FIG. 5 is an exploded perspective view of the LED lamp unit, and FIGS. 6 and 7 are rear views of the light guide plate showing a light diffusion pattern.

  The LED lamp unit 1 according to the present embodiment is used as a vehicular lamp, and as shown in FIGS. 1 to 5, a light guide plate 2, an LED 3 as a light source, a reflecting plate 4, and an outer plate. The lens 5 is used.

  The light guide plate 2 is made of a light guide material such as polycarbonate (PC), for example. As shown in FIGS. ) Is bent at a substantially right angle, and is formed in an L shape as a whole. The substantially rectangular plate-like flat plate portion 2B above the bent portion 2A of the light guide plate 2 is formed to have a wedge-shaped cross section whose thickness decreases upward as shown in FIG. The front surface of the flat plate portion 2B constitutes the emission surface 2a, and the back surface constitutes the reflection surface 2b. The emission surface 2a and the reflection surface 2b are curved in the XZ plane and the YZ plane. Is forming.

  Here, a plurality of round light diffusion patterns 6 are formed on the reflecting surface 2b of the light guide plate 2 as shown in FIG. 6, or a polygon (in the example shown, a quadrangle) as shown in FIG. A plurality of light diffusion patterns 6 are formed. These light diffusion patterns 6 are formed in a concave or convex shape by embossing, painting, printing or dot processing. In the example shown in FIG. 6, the light diffusion pattern 6 faces upward (the light introduction direction in the flat plate portion 2B of the light guide plate 2). Thus, the arrangement density of the light diffusion pattern 6 is gradually increased. In the example shown in FIG. 7, the size of the polygonal concave or convex constituting the light diffusion pattern 6 is gradually increased upward. Although not shown, the depth of the round or polygonal concave or convex constituting the light diffusing pattern 6 may be gradually increased upward, or the concave or convex constituting the light diffusing pattern 6 may be increased. These may be changed as described above by arbitrarily combining the arrangement density, size, and depth.

  Further, the corner portion of the bent portion 2A formed at the lower end portion of the light guide plate 2 is cut at an angle of about 45 ° to form a slanted reflecting surface 2c, and the end surface of the bent portion 2A is the light introducing surface 2d. Is forming. In addition, you may make it raise the reflectance by giving aluminum vapor deposition etc. to the upper surface 2e and the lower surface 2f of the bending part 2A of the light-guide plate 2, and the reflective surface 2c.

  Then, on the back side (left side in FIG. 2) of the light introduction surface 2d formed in the bent portion 2A of the light guide plate 2, a plurality of (three in the illustrated example) LEDs 3 are so wide as to face the light introduction surface 2d. They are juxtaposed at appropriate intervals in the direction (Y direction). Here, each LED 3 is arranged such that its optical axis coincides with the light emitting direction (X direction) from the light guide plate 2, that is, the optical axis of the LED lamp unit 1.

  Although not shown, each LED 3 is formed by die bonding an LED chip to one of a positive electrode and a negative electrode conductive portion (conductive pattern) formed on an insulating substrate by an appropriate means such as etching, and the upper surface electrode of the LED chip. And a conductive portion of the other electrode are wire-bonded, and then a sealing mold is formed by transfer molding with a transparent epoxy resin using a predetermined mold. When a driving voltage is applied to the LED chip of the LED 3, the LED chip emits light, and the light passes through the transparent sealing portion and is emitted to the outside as illumination light.

  The reflection plate 4 is disposed on the back side of the light guide plate 2 (the reflection surface 2b side of the light guide plate 2), and the flat plate portion 4A has the same curvature as the reflection surface 2b of the light guide plate 2 and the XZ plane and the YZ plane. The surface of the light guide plate 2 that faces the reflecting surface 2b is formed as a reflecting surface 4a. Further, a bent portion 4B that is obliquely bent at a predetermined angle toward the light guide plate 2 (toward the right in FIG. 2) is formed at the upper end portion of the reflecting plate 4, and this bent portion 4B is formed. The inner surface on the side facing the light guide plate 2 is a reflecting surface 4b.

  The outer lens 5 covers the light guide plate 2, the LED 3, and the reflection plate 4 from the front side, and is molded in a three-dimensional curved shape with a transparent resin.

  In the LED lamp unit 1 configured as described above, the emitted light emitted from each LED 3 in the X direction is bent from the light introduction surface 2d of the bent portion 2A of the light guide plate 2 as shown in FIG. 2A, is reflected by the reflecting surface 2c, is directed upward in the flat plate portion 2B of the light guide plate 2, and a part of the light L1 is emitted outside from the reflecting surface 2b of the light guide plate 2 to the reflecting plate 4. Finally, after being reflected by the reflecting surface 4a of the reflecting plate 4 and entering the light guide plate 2 again, the light is emitted from the emitting surface 2a of the light guide plate 2 toward the front in the horizontal direction (X direction). The other part of the light L2 is reflected by the reflecting surface 2b of the light guide plate 2 and then emitted from the exit surface 2a of the light guide plate 2 toward the front in the horizontal direction (X direction) as the irradiation light L. 2 is emitted to the outside from the upper end surface 2g and reflected by the reflection surface 4b of the bent portion 4B formed at the upper end of the reflection plate 4 as the irradiation light L horizontally forward ( Irradiation toward (X direction). In this way, the light L3 passing upward from the upper end surface 2g of the light guide plate 2 is reflected horizontally forward (X direction) by the reflection surface 4b of the bent portion 4B formed on the reflection plate 4 and used as the irradiation light L. The light use efficiency is increased, and the illuminance and luminance of the LED lamp unit 1 used as a vehicular lamp are increased. In particular, when the LED lamp unit 1 is used as a vehicular lamp as in the present embodiment, the light from the LED 3 is reflected to the inside of the vehicle as it goes to the outside of the vehicle where sneaking is severe. The direction of light can be controlled in the vehicle front-rear direction by the reflecting surface 4 b of the bent portion 4 B of the reflecting plate 4.

  By the way, in this embodiment, since the light diffusion pattern 6 as shown in FIG. 6 or 7 is formed on the reflection surface 2b of the light guide plate 2, the light reflected by the reflection surface 2b is diffused by the light diffusion pattern 6 and uniform. And lighting with no unevenness in brightness becomes possible. In the example shown in FIG. 6, the arrangement density of the light diffusion patterns 6 is gradually increased upward (light introduction direction in the flat plate portion 2B of the light guide plate 2). In the example shown in FIG. Since the size of the polygonal concave or convex is gradually increased upward, the irradiation light L emitted from the emission surface 2a of the light guide plate 2 is made more uniform in the vertical direction and bright in the vertical direction. Uniform illumination without unevenness is possible (refer to JP 2004-363059 A for details regarding this).

  Thus, in the present embodiment, the LED 3 is arranged so that its optical axis coincides with the direction of light emission from the light guide plate 2 (X direction), and the LED 3 is introduced into the bent portion 2A of the light guide plate 2. Since the reflecting surface 2c is provided as a reflecting means for reflecting light in a direction (upward) perpendicular to the light emitting direction from the light guide plate 2, radial (V-shaped) light emission (see FIG. 8) due to the characteristics of the LED 3 is guided. The light that is made by the bent portion 2A of the light plate 2 and is reflected by the reflecting surface 2c and goes upward in the flat plate portion 2B of the light guide plate 2 becomes uniform light without unevenness. As a result, uniform irradiation light L with no unevenness is emitted from the emission surface 2a of the light guide plate 2, and the entire surface (region of height H1) of the emission surface 2a can be practically used as illumination.

  Further, in the present embodiment, the LED 3 is not disposed directly under the light guide plate 2 but is disposed beside the light guide plate 2 so as to overlap the light guide plate 2 in the height direction, so that an extra height space is required for the installation of the LED 3. And not.

  As a result of the above, in the LED lamp unit 1 according to the present embodiment, the overall height H is set by the height H2 ′ of the region where the light unevenness occurs in the conventional LED lamp unit 101 shown in FIGS. It can be shortened (H <H ′), and the whole can be made compact and compact accordingly. In particular, when the LED lamp unit 1 is used as a vehicular lamp as in the present embodiment, the layout can be advantageously performed, so the effect of downsizing is enormous.

  Although the present invention has been described with respect to an embodiment in which the present invention is applied to an LED lamp unit used as a vehicular lamp, the present invention is an LED lamp unit used for other arbitrary applications such as a general illumination light source. Of course, the same applies to the above.

It is a front view of the LED lamp unit which concerns on this invention. It is the sectional view on the AA line of FIG. It is the BB sectional view taken on the line of FIG. It is a perspective view of the LED lamp unit which concerns on this invention. It is a disassembled perspective view of the LED lamp unit which concerns on this invention. In the rear view of the light guide plate showing the light diffusion pattern In the rear view of the light guide plate showing the light diffusion pattern It is a front view of the conventional LED lamp unit. It is CC sectional view taken on the line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 LED lamp unit 2 Light guide plate 2A Bending part of a light guide plate 2B Flat plate part of a light guide plate 2a Output surface of a light guide plate 2b Reflection surface of a light guide plate 2c Reflection surface (reflection means) of a light guide plate
2d Light introduction surface of light guide plate 2e Upper surface of bent portion 2f Lower surface of bent portion 2g Upper end surface of light guide plate 3 LED
4 reflective plate 4A flat plate portion of reflective plate 4B bent portion of reflective plate 4a reflective surface of flat plate portion 4b reflective surface of bent portion 5 outer lens 6 light diffusion pattern H total height of LED lamp unit H1 height of light emitting surface of light guide plate L irradiation light L1-L3 light

Claims (5)

In an LED lamp unit comprising a light guide plate, an LED disposed facing the light introduction surface of the light guide plate, and a reflective plate disposed on the reflective surface side of the light guide plate,
The LED is arranged so that its optical axis coincides with the light output direction from the light guide plate, and the light introduced from the LED to the light guide plate is reflected in a direction perpendicular to the light output direction from the light guide plate. An LED lamp unit having a surface provided on a light guide plate.   A bent portion that is bent at a substantially right angle with respect to the exit surface of the light guide plate is formed at an end portion of the light guide plate. The LED lamp unit according to claim 1, wherein the reflecting surface is formed.   A bent portion that is obliquely bent in the optical axis direction of the LED is formed at an end of the reflective plate, and at least a surface of the bent portion that faces the light guide plate is used as a reflective surface. The LED lamp unit according to claim 1 or 2.   Whether a plurality of light diffusion patterns having the same shape are formed on the reflection surface of the light guide plate facing the reflection plate, and the arrangement density of the light diffusion patterns is gradually increased along the light introduction direction to the light guide plate The LED lamp unit according to any one of claims 1 to 3, wherein the size is gradually increased, the depth is gradually increased, or a combination thereof.   5. The LED lamp unit according to claim 4, wherein the diffusion pattern is formed into a round or polygonal concave or convex shape by embossing, painting, printing, or dot processing.

Images