JP2008071598A - Lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting device capable of illumination with reduced color shading due to emission colors of two or more kinds of LEDs, and suitable for thinning the device. <P>SOLUTION: The lighting device 3 is provided with a light guide member 5, a light-emitting part 8, and a light distribution control member 11. The light guide member 5 has one end with an incident face 5a formed and the other end with a reflective face 5b formed. The light guide member 5 guides light incident from the incident face 5a to the other end, and reflect it at the reflective face 5b at the other end to be irradiated from the other end. The light-emitting part 8 is formed of at least two kinds of LEDs 8a to 8c with different emission colors. The light-emitting part 8 is arranged in opposition to the incident face 5a. The light distribution control member 11 is arranged in opposition to the other end of the light guide member 5. Light irradiated from the light guide member 5 is distributed in a direction different from a light guide direction at the light guide member 5 by the light distribution control member 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an illumination device including two or more types of LEDs (light emitting diodes) having different emission colors.

2. Description of the Related Art Conventionally, a technique for distributing light emitted from an LED through a bowl-shaped collimator lens having a recess in which the LED is disposed is known. In this technique, the light emitted from the LED can be refracted and reflected by a collimator lens and emitted as parallel beam illumination light from the exit surface of the collimator lens (see, for example, Patent Document 1).
Japanese translation of PCT publication No. 2002-528861 (0001-0015, FIG. 1 to FIG. 3)

  Patent Document 1 does not describe obtaining desired color rendering properties with illumination light emitted from a collimator lens. By the way, since LEDs cannot emit light other than the three primary colors of light or a color obtained by mixing them, in order to obtain a desired color rendering color, a red LED, a green LED, a blue LED, and a white LED are combined. Therefore, it is necessary to mix the emission colors of the combined LEDs.

  Therefore, the inventor made a prototype of an illumination device in which two or more kinds of LEDs having different emission colors are arranged in the recess of the collimator lens, but it has been found that color unevenness occurs on the irradiated surface. This is considered to be due to the fact that the collimator lens projects the light emitting part of the LED onto the irradiation surface. That is, according to the arrangement of a plurality of arranged LEDs, the light emitting portions of these LEDs are projected on the irradiation surface, and as a result, colors are mixed in the portion where adjacent light regions overlap, but the other colors are not mixed. I didn't get the street results.

  An object of the present invention is to provide an illumination device suitable for reducing the thickness of the device while performing illumination with reduced color unevenness due to the emission colors of two or more types of LEDs.

  The invention of claim 1 has one end portion and the other end portion, guides the light incident from the incident surface formed at the one end portion to the other end portion, and reflects it by the reflecting surface formed at the other end portion. A light guide member that emits light from the other end portion; a light emitting portion that is arranged to face the incident surface and has at least two types of LEDs that emit light different from each other; and a light guide portion that is arranged to face the other end portion. And a light distribution control member that distributes light emitted from the member in a direction different from the light guide direction of the light guide member.

  In the present invention, the light guide member can be formed of a translucent material, such as a translucent synthetic resin or glass. As the light-transmitting synthetic resin, an acrylic resin can be suitably used, and in this case, it is preferable in terms of excellent mass productivity. It is preferable that the light guide member is made of translucent glass because the light guide member can be used without causing heat deformation and the like even if the LED generates a large amount of heat.

  In this invention, the cross-sectional shape of the light guide member in the direction orthogonal to the light guide direction can be arbitrarily determined such as a cross-sectional shape surrounded by a flat surface and an arc in addition to a rectangle and a round shape. However, when the cross section of the light guide member is rectangular or round, it is preferable that the number of reflections of light guided by the light guide member can be increased as the width and diameter of the cross section are smaller.

  In the present invention, the reflecting surface is preferably formed by an inclined surface made of a flat surface, but is not limited thereto, and may be formed by a curved surface. Further, the reflection surface may be a total reflection surface formed by mirror finishing, for example, or a diffuse reflection surface having a flatness of the surface rougher than that of the total reflection surface. It is preferable that the reflection surface be a total reflection surface because light can be efficiently emitted toward the light distribution control member without waste. It is preferable that the reflection surface be a diffuse reflection surface in that the color mixing performance can be improved by increasing the number of reflections of light at the other end of the light guide member. In addition, the inclination angle of the reflecting surface with respect to the light guide member can be determined in a range of 45 ° ± 5 °, and in order to reflect light efficiently, the inclination angle of the reflecting surface is preferably 45 ° ± 1 °. .

  In the present invention, at least two types of LEDs having different emission colors include a red LED, a green LED, a blue LED, and a white LED that achieves white light emission by combining a blue LED with a fluorescent substance that emits yellow fluorescence, for example. You can select and use. When the desired light color is white, a red LED, a green LED, and a blue LED can be used in combination. When the desired light color is other than white, the red LED, the green LED, and the blue LED can be used. Among them, one or two colored LEDs and a white LED can be used in combination. Therefore, it is possible to configure an illumination device including one or more LED chips each having a plurality of LEDs having different emission colors as one light source, and a plurality of illumination devices constituting an LED package. When these LEDs are provided, two or more kinds of LEDs having different emission colors can be used for these LEDs.

  In the present invention, the light distribution control member may be a lens, a prism, a reflector, or the like made of a translucent material such as translucent synthetic resin or glass.

  In the invention of claim 1, the light of different colors emitted from each LED is mixed by being repeatedly reflected in the light guide member while propagating from the incident surface of the light guide member toward the reflection surface. The light is reflected by the reflecting surface and emitted toward the light distribution control member. Therefore, the reflection surface of the light guide member serves as a pseudo light source unit when viewed from the light control member. The light incident on the light distribution control member from the pseudo light source unit is light that does not show the color of light emitted from each LED due to the above-described color mixing operation at the light guide member, and thus has no color unevenness. However, although the light is distributed by controlling the light, it is possible to perform illumination with reduced color unevenness on the irradiated surface.

  By the way, the thickness of the illuminating device of this invention is prescribed | regulated by the light distribution control member and the light guide member. Under such regulations, the light distribution direction of the light distribution control member is different from the light guide direction of the light guide member, so that the light guide member extends in the direction opposite to the light distribution direction of the light distribution control member. The control members are not combined so as to be linearly arranged. Thereby, the thickness of the lighting device can be reduced.

  The invention of claim 2 uses a pair of the light guide members, arranges the pair of light guide members so that the other end portions of the light guide members are abutted with each other, and sets the reflective surfaces of the light guide members to each other. It is characterized by being continuous.

  In this invention, since the reflecting surfaces of the pair of light guide members are continuous, the irradiation surface can be illuminated brightly according to the fact that the light amount of the pseudo light source unit viewed from the light distribution control member is doubled.

  The invention according to claim 3 is characterized in that an inclined side surface, which is thinned as the light guide member approaches at least the reflective surface side, is provided on the light guide member so as to be continuous with the reflective surface. It is said.

  In this invention, the number of times the different colors emitted by the LEDs are reflected in the light guide member is increased in accordance with the light guide member becoming thinner due to the inclined side surface, thereby improving the mixing performance of light of different colors. it can. In addition, since the inclined side surface is provided continuously to the reflection surface, the area of the reflection surface forming the pseudo light source portion is reduced as viewed from the light distribution control member. For this reason, a pseudo light source part becomes small and light distribution control by a light distribution control member can be facilitated.

  According to the invention which concerns on Claim 1, while being able to perform the illumination by which the color nonuniformity by the luminescent color of two or more types of LED was reduced, the suitable illuminating device for making apparatus thickness thin can be provided.

  According to the invention of claim 2, in the illumination device of the invention of claim 1, the irradiation surface can be illuminated brightly.

  According to the invention of claim 3, in the lighting device of the invention of claim 1 or 2, color unevenness is reduced by further improving the mixing performance of light of different colors emitted by two or more kinds of LEDs. Light distribution control by the light distribution control member can be facilitated.

  With reference to FIG.1 and FIG.2, the illuminating device of 1st Embodiment of this invention is demonstrated.

  Reference numeral 1 in FIG. 1 indicates a lighting fixture. The lighting fixture 1 is formed by attaching one or more, for example, a plurality of lighting devices 3 to the fixture body 2.

  The instrument body 2 is formed of a housing having one surface, for example, a lower surface opened, and the opened surface serving as an irradiation opening. The instrument body 2 includes a device mounting member 2a, and the device mounting member 2a is preferably formed of a material having higher thermal conductivity than that of a synthetic resin, for example, a metal, specifically, iron or aluminum alloy. By making the device mounting member 2a metal, the device mounting member 2a can be used as a heat dissipation element. Note that the lighting device 3 (not shown) is attached to the fixture body 2.

  The illumination device 3 is an LED module that includes a light guide member 5, a light emitting unit 8, and a light distribution control member 11. The illuminating device 3 connects the light emitting portion 8 as a heat generation source to the device mounting member 2a so as to be able to conduct heat, and a light emitting surface (to be described later) of the light distribution control member 11 is opposed to the irradiation opening, thereby mounting the device mounting member. 2a. The lighting device 3 is used in a number necessary for obtaining the brightness required for the lighting device 1 according to the usage environment of the lighting device 1, and in FIG. However, the illumination direction of each illuminating device 3 may differ according to a use application.

  The light guide member 5 of each illuminating device 3 is formed of translucent synthetic resin such as acrylic resin, for example, and a pair of light guide members 5 is used in this embodiment. As shown in FIGS. 2A and 2B, these light guide members 5 are formed in a flat plate shape in which an incident surface 5a is formed at one end and a reflecting surface 5b is formed at the other end. The first side surface 5c to the fourth side surface 5f of the light guide member 5 extending between the incident surface 5a and the reflective surface 5b form peripheral surfaces that are continuous at right angles. The first side surface 5c and the second side surface 5d are parallel to each other, and the third side surface 5e and the fourth side surface 5f are parallel to each other.

  The incident surface 5a is continuous at right angles to the first side surface 5c to the fourth side surface 5f. The reflective surface 5b is inclined at an angle of approximately 45 ° (45 ° ± 1 °), is continuous with an acute angle with respect to the first side surface 5c, and is obtuse with respect to the second side surface 5d. Is continuous. The reflection surface 5b is made of, for example, a diffuse reflection surface. The width A of the light guide member 5 is set to twice the thickness B of the light guide member 5.

  The pair of light guide members 5 are arranged in combination so that the other end portions are abutted with each other, thereby making the reflecting surfaces 5b of the pair of light guide members 5 continuous as shown in FIG. Yes. Due to the arrangement and the relationship between the width A and the thickness B, the continuous reflecting surfaces 5b are continuously formed in a square shape as shown in FIG. It comes to function as a part. The pair of light guide members 5 are attached to the instrument body 2 with their second side surfaces 5d in contact with the device attachment member 2a.

  The light emitting unit 8 is supported so as to conduct heat to the device mounting member 2 a and is disposed to face the incident surface 5 a of each light guide member 5. The light emitting unit 8 includes at least two kinds of LEDs (light emitting diodes) having different emission colors. For example, in the present embodiment, the light emitting unit 8 includes a red LED 8a, a green LED 8b, and a blue LED 8c in order to obtain white illumination light. These three types of red LED 8a, green LED 8b, and blue LED 8c are arranged along the width direction of the light guide member 5 with respect to the incident surface 5a as shown in FIG.

  The light distribution control member 11 made of a translucent material is made of, for example, a lens having a rotationally symmetrical shape with the optical axis 11a as the center. The light distribution control member 11 has a recess 11b at the center, an outer surface 11c that is curved continuously from the opening end of the recess 11b, and a light emitting surface 11d that is a flat surface continuous to the outer surface 11c. I have. The light exit surface 11d is circular. The inner surface of the recess 11b is formed by a lens surface 11e. The light distribution control member 11 can emit light from the light exit surface 11d as light parallel to the optical axis 11a by refracting the light incident on the recess 11b by the lens surface 11e and totally reflecting the light by the outer surface 11c. .

  As shown in FIGS. 2A and 2B, the light distribution control member 11 has a pair of light guide members 5 in such a manner that the pseudo light source portion composed of the reflection surface 5b is opposed to the central portion of the recess 11b. Is combined with. The opening end of the recess 11 b is in contact with the first side surface 5 c of the light guide member 5. Therefore, the light guide members 5 that are continuous with each other intersect with the optical axis 11 a of the light distribution control member 11, and are specifically disposed orthogonally.

  Each illuminating device 3 having the above-described configuration can be illuminated by turning on its light emitting portion 8. In this illumination, light emitted from the red LED 8 a, the green LED 8 b, and the blue LED 8 c of the light emitting unit 8 that is turned on enters the light guide member 5 through the incident surface 5 a at one end of the light guide member 5. . In this case, the incident light is refracted by the incident surface 5 a and converges within an angle of 42 ° and enters the light guide member 5.

The three colors of light incident in this way are guided from the incident surface 5a of the light guide member 5 toward the reflection surface 5b at the other end of the light guide member 5 on the side surfaces 5c to 5f of the light guide member 5. It is mixed by being repeatedly reflected. The mixed light is reflected toward the light distribution control member 11 by the reflection surface 5b, and is emitted from the first side surface 5c to the central portion of the recess 11b of the light distribution control member 11 at the other end of the light guide member 5. The The emitted light is emitted in a direction substantially perpendicular to the light guide direction in the light guide member 5 and is incident on the light distribution control member 11. Then, the light incident on the light distribution control member 11 is controlled by the light distribution control member 11 and emitted from the light emission surface 11d toward the irradiation target, thereby following the optical design of the light distribution control member 11. In the illumination described above, the reflection surfaces 5b of the pair of light guide members 5 that serve as light incident sources to the indentations 11b when viewed from the light distribution control member 11 function as pseudo light source portions. . The light incident on the light distribution control member 11 from the pseudo light source unit is light mixed in the process of being guided from the incident surface 5a of the light guide member 5 to the reflecting surface 5b as described above. The red LED 8a, the green LED 8b, and the blue LED 8c do not appear individually, and the light has no color unevenness. For this reason, although the said light source control part 11 projects the said pseudo light source part on an irradiation surface, the illumination which reduced the color nonuniformity in an irradiation surface can be performed.

  In addition, since the reflecting surface 5b is a diffuse reflecting surface in the present embodiment, the light component emitted from the first side surface 5c perpendicular to the first side surface 5c causes the reflecting surface 5b to be a total reflection surface. On the other hand, as the light can be reflected between the first side surface 5c and the reflecting surface 5b, the mixing of light of different colors can be further promoted. Therefore, illumination with reduced color unevenness on the irradiated surface can be achieved. The reflecting surface 5b made of a diffuse reflecting surface is preferable in terms of processing because it does not require a mirror finish as compared with the reflecting surface 5b made of a total reflecting surface.

  The pseudo light source part is formed by arranging the reflecting surfaces 5b of the light guide members 5 to be continuous with each other by arranging the other end portions of the pair of light guide members 5 to face each other. Due to the relationship between the width A and the thickness B of the member 5, the member 5 is formed in a square shape when viewed from the light distribution control member 11. For this reason, in the said illumination, the light radiate | emitted from the light distribution control member 11 is distributed as a square illumination pattern. Moreover, since the reflective surfaces 5b of the pair of light guide members 5 are continuous, the reflective surface 5b of one light guide member 5 is configured to face the central portion of the recess 11b of the light distribution control member 11. Compared to the case, the light amount of the pseudo light source unit viewed from the light distribution control member 11 is doubled, and accordingly, the irradiation surface can be illuminated brightly.

  2A is defined by the light distribution control member 11 and the light guide member 5 that overlap in the thickness direction. By the way, since the light distribution direction of the light distribution control member 11 is different from the light guide direction in the light guide member 5, the light guide member 5 extends in the direction opposite to the light distribution direction of the light distribution control member 11. The light control member 11 is not combined so as to be linearly arranged. Thereby, the thickness T of the illumination device 3 can be reduced. Moreover, since the red LED 8a, the green LED 8b, and the blue LED 8c are arranged side by side in the direction in which the optical axis 11a extends, in other words, in the direction orthogonal to the thickness direction of the illumination device 1, the illumination device 1 required for arranging these LEDs is arranged. The space along the thickness direction can be reduced, and this is also preferable for reducing the thickness T of the lighting device 3. In addition, the light guide distance in the light guide member 5, that is, the length from the incident surface 5a to the reflective surface 5b can be ensured sufficiently long regardless of the reduction in thickness, so that the above-described color mixing effect is sufficiently exhibited. be able to.

  3A and 3B show a second embodiment of the present invention. The second embodiment is the same as the first embodiment except for the matters described below, including the configuration not shown in FIG. Therefore, the same parts as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and the description thereof is omitted.

  In 2nd Embodiment, as shown to FIG. 3 (A), the 2nd side surface whole of the light guide member 5 is inclined, and the 2nd side surface is made into the inclined side surface 5g. The inclined side surface 5g is continuous with the reflecting surface 5b with an obtuse angle therebetween, and the entire light guide member 5 is made thinner as it approaches the reflecting surface 5b. Therefore, in the second embodiment, the inclined side surface 5g formed of the second side surface is not parallel to the first side surface 5c. At the same time, the area of the reflecting surface 5b formed of the inclined surface that forms the pseudo light source portion when viewed from the light distribution control member 11 can be reduced by the inclined side surface 5g, so that the square of the pseudo light source portion formed by the reflecting surfaces 5b of the pair of light guide members 5 The size of can also be reduced. In addition to providing the inclined side surface 5g as described above in order to make the pseudo light source part formed by the reflecting surfaces 5b of the pair of light guide members 5 into a small square shape, the width C of the light guide member 5 is determined as follows. The thickness is set to be less than twice the thickness B of the incident surface 5a of the optical member 5.

  Except for the items described above, the second embodiment is the same as the first embodiment. Therefore, the illumination device 3 of the second embodiment obtains the same operation as that of the first embodiment, and can perform illumination with reduced color unevenness due to the respective emission colors of the red LED 8a, the green LED 8b, and the blue LED 8c. The thickness T can be reduced.

  Moreover, it is superior to the first embodiment in the following points. That is, since the light guide member 5 is thinned by the inclined side surface 5g, the number of times that different colors emitted from the red LED 8a, the green LED 8b, and the blue LED 8c are reflected in the light guide member 5 is increased accordingly. It is. Thereby, as the light mixing performance in the light guide member 5 is improved, illumination with less color unevenness due to the emission color can be performed. Further, as the light guide member 5 is thinned by the inclined side surface 5g, the area of the reflecting surface 5b where the inclined side surface 5g continues can be reduced as shown in FIG. For this reason, since the pseudo light source part seen from the light distribution control member 11 becomes small, the light distribution control by the light distribution control member 11 can be facilitated.

  In the second embodiment, the inclined side surface 5g is formed on the second side surface. However, the inclined side surface 5g can be formed on the first side surface 5c, and the inclined side surface 5g can be formed on the third side surface 5e and the fourth side surface 5f. Can also be provided. In the second embodiment, the inclined side surface 5g is formed on the entire second side surface. Instead, the inclined side surface 5g may be provided at least on the reflective surface 5b side of the light guide member 5. it can.

  4A and 4B show a third embodiment of the present invention. In the third embodiment, the pair of light guide members 5 are integrally formed. Matters other than this point are the same as those of the first embodiment including a configuration not shown in FIG. Therefore, the same parts as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and the description thereof is omitted.

  Therefore, in the illumination device 3 of the third embodiment, the same operation as that of the first embodiment can be obtained, and illumination with reduced color unevenness due to the emission colors of the red LED 8a, the green LED 8b, and the blue LED 8c can be performed. The thickness T can be reduced. And it is preferable at the point which can handle a pair of light guide member 5 integrally in an assembly.

  FIG. 5 shows a fourth embodiment of the present invention. The fourth embodiment is the same as the first embodiment, including the configuration not shown in FIG. Therefore, the same parts as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof is omitted.

  In the fourth embodiment, the light distribution control member 11 has a rod shape. Therefore, the recess 11 b is formed in a groove shape extending in the longitudinal direction of the light distribution control member 11, and the light emitting surface 11 d has a rectangular shape extending in the longitudinal direction of the light distribution control member 11. At the same time, a pair of outer surfaces 11c extending between the opening end of the recess 11b and the light emitting surface 11d are formed as arcuate surfaces. The pair of light guide members 5 is a flat plate extending in the same direction as the light distribution control member 11. Therefore, both the incident surface 5 a and the reflecting surface 5 b of the light guide member 5 extend in the longitudinal direction of the light guide member 5. For example, a plurality of light emitting units 8 in which red LEDs 8a, green LEDs 8b, and blue LEDs 8c are arranged are arranged opposite to the incident surface 5a of the light guide member 5 at intervals in the longitudinal direction of the incident surface 5a. .

  Except for the items described above, the second embodiment is the same as the first embodiment. Therefore, the illumination device 3 of the fourth embodiment obtains the same operation as that of the first embodiment, and can perform illumination with reduced color unevenness due to the emission colors of the red LED 8a, the green LED 8b, and the blue LED 8c. The thickness T can be reduced.

  In addition, this invention is not restrict | limited to the said each embodiment. For example, a plurality of LEDs having different emission colors can be arranged side by side in the thickness direction of the light guide member 5, and in this case, the size of the pseudo light source unit viewed from the light distribution control member 11 side is further reduced. Light control becomes easy. The light guide member 5 can be formed in a curved shape instead of a flat plate, and preferably arranged along the outer surface 11 c of the light distribution control member 11.

Sectional drawing which shows the lighting fixture which used the illuminating device which concerns on 1st Embodiment of this invention as a light source. FIG. 2A is a side view showing a partial cross section of the lighting device according to the first embodiment. (B) is a top view which shows a pair of light guide member with which the illumination device is provided. (A) is a side view showing a partial cross section of a lighting device according to a second embodiment of the present invention. (B) is a top view which shows a pair of light guide member with which the illumination device is provided. (A) is sectional drawing which shows the illuminating device which concerns on 3rd Embodiment of this invention. (B) is a top view which shows a pair of light guide member with which the illumination device is provided. The perspective view which shows a part of illuminating device which concerns on 4th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 3 ... Illuminating device, 5 ... Light guide member, 5a ... Incident surface of light guide member, 5b ... Reflective surface of light guide member, 5c-5f ... Side surface of light guide member, 5g ... Inclined side surface of light guide member, 8 ... Light emitting part, 8a ... red LED, 8b ... green LED, 8c ... blue LED, 11 ... light distribution control member, 11d ... light emitting surface of light distribution control member, T ... thickness of illumination device

Claims (3)

It has one end and the other end, and the light incident from the incident surface formed at the one end is guided to the other end, reflected by the reflecting surface formed at the other end, and emitted from the other end. A light guide member to be made;
A light-emitting portion that is arranged to face the incident surface and is composed of at least two kinds of LEDs having different emission colors;
A light distribution control member arranged to face the other end and distributes light emitted from the light guide member in a direction different from the light guide direction of the light guide member;
An illumination device comprising:   A pair of the light guide members are used, the pair of light guide members are arranged so that the other end portions of the light guide members are abutted with each other, and the reflection surfaces of the light guide members are made continuous. The lighting device according to claim 1.   3. The light guide member according to claim 1, wherein an inclined side surface that is thinned toward a portion of the light guide member that is closer to the reflective surface is provided on the light guide member so as to be continuous with the reflective surface. The lighting device described in 1.

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