JP2007048883A - Optical element for changing direction of light, light source unit for radiating light, and planar light emitting device employing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical element for changing the direction of light in which the occurrence of unevenness in color and light emission can be prevented while using the appropriate number of light sources depending on the scale or demand for lighting without complicating the arrangement, and to provide a light source unit for radiating light and a planar light emitting device employing it. <P>SOLUTION: An optical element for changing the direction of light having an incident face for receiving light radiated from a light source through an incident layer, a reflective face of bugle-shape for reflecting light entering from the incident face, and a sidewall face for exiting the light reflected on the reflective face in the side face direction while refracting mixes light from a plurality of light sources and emits light from a diffuse transmission portion of the planar light emitting device. Variations are averaged in quantity of emitted light and in color, and a planar light emitting device in which unevenness in light emission and color is suppressed is obtained. Since light is exited from a light source unit for radiating light in the lateral direction, an arrangement especially suitable for thinning and high output can be attained. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light emitting diode (Light Emitting Diode: LED) as a light source, a light direction changing optical element that changes the light direction of the light source, a light emitting light source unit that combines a light source and a light direction changing optical element, and With respect to a planar light emitting device using the same, it is possible to suppress the occurrence of color unevenness and light emission unevenness, in particular, without complicating the configuration, using an appropriate number of light sources according to the scale and demand of illumination. The present invention relates to an optical element for changing light direction, a light source unit for light emission, and a planar light emitting device using the same.

  Conventionally, fluorescent lamps have been widely used as light sources in planar light emitting devices used for video display, illumination, and the like. However, fluorescent lamps are harmful because they use mercury, have a short life and a high running cost, and have various problems such as requiring appropriate treatment as industrial waste. In order to solve such a problem, a planar light emitting device using an LED as a light source has been proposed and put into practical use. And in recent years, the light power of LEDs has increased, and energy saving and clean light sources that do not contain environmentally hazardous substances include light sources such as signboards, backlights for televisions, and lighting equipment that have been illuminated with light sources such as light bulbs and fluorescent lamps. LED has been replaced.

  Since LEDs are manufactured based on semiconductor manufacturing technology, they have features that are excellent in mass productivity and cost saving. In recent years, white LEDs having a luminous efficiency exceeding 60 lm / W have been put into practical use and are expected to be applied to lighting applications. However, since they are point light sources, they can achieve desired illuminance while suppressing uneven illuminance as a planar light emitting device. In order to obtain the above, it is necessary to appropriately arrange a plurality of LEDs.

  In addition, the brightness of LEDs depends on the light emission characteristics of the LED element that is the light source, but it is known that there is uneven color and uneven brightness of the LED element alone, and light emission is required in applications that require illumination quality. It is required to prepare LED elements having uniform characteristics. In reality, LEDs that fall within an allowable range for desired light emission characteristics are selected and used.

  Assuming that the illuminance can be made uniform even if individual LEDs have variations in light emission characteristics, a wiring board as an element mounting board, a plurality of LED light sources arranged in parallel on the element mounting surface of the wiring board, and these LED light sources There has been proposed a planar light emitting device including a light guide member with a diffusing portion for guiding emitted light from a light source to an illumination target (see, for example, Patent Document 1).

  According to the planar light emitting device of Patent Document 1, the LED light source on the wiring board is turned on, and the lighting light is diffused in a planar shape in the light guide member, and then the entire back surface of the liquid crystal panel as an illumination target is irradiated. ing.

In addition, a lens that makes light emitted from an LED light source perpendicular to the lens center axis by total internal reflection of the lens and a sawtooth lens, and a light emitting device using the lens have been proposed (for example, patents). References 2 and 3).
JP 2004-14365 A JP 2003-8068 A JP 2003-8081 A

  However, according to the planar light emitting device of Patent Document 1, since light emitted from a plurality of LEDs is propagated into the light guide member and radiated in a planar shape, a light transmissive material with little light loss is selected and guided. It is necessary to form an optical member. Moreover, when an irradiation area becomes large, it is necessary to arrange | position LED appropriately in several places with respect to a light guide member, and the restriction | limiting on a design may arise. Further, since the light guide member is required, there is a problem that the apparatus cost is increased.

  In addition, according to the lenses of Patent Documents 2 and 3, and the light emitting device using the lens, the cost of the apparatus increases because a sawtooth lens having a complicated shape is required. Since light only in the direction is emitted, it is not sufficient to suppress the occurrence of uneven color and uneven light emission.

  Accordingly, an object of the present invention is to change the direction of light without complicating the configuration, using an appropriate number of light sources according to the scale and demand of illumination, and suppressing the occurrence of uneven color and uneven light emission. An object is to provide an optical element, a light source unit for light emission, and a planar light emitting device using the same.

  In order to achieve the above object, the present invention provides an incident surface that receives light emitted from the light source through an incident layer from a light source, a reflective surface having a morning glory shape that reflects light incident from the incident surface, There is provided a light direction changing optical element, comprising: a side wall surface that refracts light reflected by the reflecting surface and emits the light in a side surface direction.

  In order to achieve the above object, the present invention comprises a light source and the above-described optical element for changing the light direction disposed at a predetermined position with respect to the light source via an incident layer. A light source unit for light emission is provided.

  In order to achieve the above object, the present invention provides one or a plurality of light emitting light source units described above, a light reflecting portion that reflects light emitted from the light emitting light source unit, and the light. A diffuse transmission unit that diffuses and transmits the light in a planar shape, and the diffuse transmission unit emits light having a planar intensity that is obtained based on a mixture of light emitted from the light source unit for light emission. A planar light emitting device is provided.

  In order to achieve the above object, the present invention provides one or a plurality of light emitting light source units described above, a light reflecting portion that reflects light emitted from the light emitting light source unit, and the light. A diffuse transmission unit that diffuses and transmits the light in a planar manner, and the diffuse transmission unit emits the light of the color obtained based on the mixture of the light emitted from the light source unit for light emission in a planar manner. A planar light emitting device is provided.

  In order to achieve the above object, the present invention provides one or a plurality of light emitting light source units described above, a light reflecting portion that reflects light emitted from the light emitting light source unit, and the light. A diffuse transmission section that diffuses and transmits planar light, and the diffuse transmission section emits light having an intensity obtained based on a mixture of light emitted from a plurality of light emission light source units having different emission intensities. Provided is a planar light emitting device that emits planar radiation.

  In order to achieve the above object, the present invention provides one or a plurality of light emitting light source units described above, a light reflecting portion that reflects light emitted from the light emitting light source unit, and the light. A diffuse transmission section that diffuses and transmits planar light, and the diffuse transmission section emits light of a color obtained based on a mixture of light emitted from a plurality of light emission light source units having different emission colors. Provided is a planar light emitting device that emits planar radiation.

  In order to achieve the above object, the present invention provides one or a plurality of light emitting light source units described above, a light reflecting portion that reflects light emitted from the light emitting light source unit, and the light. An intensity obtained based on a mixture of light emitted from a plurality of light emitting units for light emission different in emission intensity and emission color. And a planar light emitting device that emits light of a color in a planar manner.

  According to the present invention, the configuration is not complicated, and an appropriate number of light sources can be used according to the scale and demand of illumination, and the occurrence of uneven color and uneven light emission can be suppressed. A thin and large surface light source with high brightness and color uniformity can be realized, and the number of LEDs used can be reduced to realize an inexpensive surface light source. In addition, a planar light source with a high degree of design freedom can be realized. In addition to the thin and large screen uniform surface light source, LCD TVs using LED backlights can be thinned, backlights added to wall-mounted posters, etc. A light source can be installed, and the degree of freedom in lighting design can be increased. Since the light is emitted in the lateral direction by the light source unit for light emission, it is possible to obtain a configuration particularly suitable for thinning and high output.

(First embodiment)
FIG. 1 is a diagram showing a light direction changing optical element and a light source according to the first embodiment. LED2 is used as a light source. The light emitted from the light emitting portion 2a of the LED 2 enters the optical direction converting optical element 8 from the incident surface 8a of the optical direction converting optical element 8 through the incident layer 80, and is condensed within a critical angle by refraction. . The light reaches the reflecting surface 8b. The reflection surface 8b has an angle that totally reflects all the light that has arrived from the LED 2, and after being totally reflected, when it reaches the side wall surface 8c, it is refracted and emitted outside the optical element 8 for light direction conversion. Most of the light is emitted from the sidewall surface 8c, and the light is emitted with a very wide viewing angle. The optical element 8 for changing light direction is a transparent material, and glass, acrylic resin, polycarbonate resin, epoxy resin, silicone resin, or the like can be used. Moreover, although the side wall surface 8c has a cylindrical shape, it may be slightly inclined and may be a part of a conical or inverted conical shape.

FIG. 2 is a diagram for explaining total reflection on the reflecting surface 8b, and the optical phenomenon on the reflecting surface 8b will be described. When the light beam LB is incident on the material having the refractive index n1 from the material having the refractive index n1, the following relationship is established according to Snell's law.
n1 · sin (θ1) = n2 · sin (θ2)
When the exit-side refractive index n2 is larger than the incident-side refractive index n1, θ2 ′ when θ1 ′ = 90 ° is called a critical angle. However, when the light enters the surface having the refractive index n1 from within the substance (refractive index n2) at an angle greater than the critical angle, the incident light beam is totally reflected. If the incident side substance is air (n = 1) and the optical element 8 for changing the light direction is acrylic (n = 1.49), the critical angle is 42.16 °.

  FIG. 3 is a view for explaining the shape of the reflecting surface 8b formed on the upper surface of the optical element 8 for changing the light direction. The light beam LB incident on the incident surface 8a of the light direction converting optical element 8 from the light emitting unit 2a through the air layer 80 becomes light within a refracted angle. The shape of the reflecting surface 8b is determined so as to satisfy the condition of totally reflecting all the light rays incident on the reflecting surface 8b. That is, as described with reference to FIG. 2, when the light direction converting optical element 8 is formed of acrylic resin, the angle formed between the incident light beam LB on the reflecting surface 8 b and the normal line 102 at the reflecting point 101 is set. When the critical angle is set to 42.16 ° or more and this is performed for all the light rays from the incident surface 8a, the reflecting surface 8b has a morning glory shape as shown in the sectional view of FIG. The morning glory-shaped reflecting surface 8b has a diameter 103 and a height 104 determined by the intersection of the incident ray angle and the morning glory shape. By setting the diameter 103 to a shape including this intersection portion, all the light incident on the optical direction conversion optical element 8 is totally reflected.

  As described above, the shape of the reflection surface 8b is determined as a condition for the total reflection of the light beam LB incident on all surfaces. However, the shape of the reflection surface 8b is simplified or equivalent. The cross-sectional shape may be a quadratic curve, particularly a part of a parabola or a hyperbola.

  FIG. 4 is a diagram showing the directivity of light rays emitted from the optical direction converting optical element 8 according to the first embodiment. The light rays emitted from the optical direction conversion optical element 8 are set so that the components emitted obliquely rearward are increased depending on the incident condition on the incident surface 8a, the cross-sectional shape of the reflecting surface 8b, the shape of the side wall surface 8c, and the like. ing. Further, the light beam emitted from the light direction converting optical element 8 is set so that there are many components emitted obliquely forward, or components emitted obliquely backward and diagonally forward.

  In order to apply a light beam emitted from the optical element for light direction conversion 8 to a thin planar light source with less intensity unevenness, the light beam emitted from the optical element for light direction conversion 8 is not emitted horizontally but shown in FIG. It is preferable to use an oblique forward ray or an oblique backward ray shown in the light emission range.

(Second Embodiment)
FIG. 5 is a diagram showing an embodiment of the optical direction converting optical element 8 showing the second embodiment in consideration of mounting. When the light direction changing optical element 8 is incident from the LED 2 which is a light source, the optical direction converting optical element 8 has a shape in which a portion where the incident surface 8a is not necessary and a portion where the side wall surface 8c is not necessary are connected by an inverted conical surface 8d. In this case, the length l of the side wall surface 8c is preferably 25% or more of L, where L is the total length of the optical element 8 for changing the light direction, as shown in the drawing. That is, the incident surface 8a is equal to or larger than the size of the light source, and can be a light direction changing optical element having a conical surface between the incident surface 8a and the side wall surface 8c.

  FIG. 6 is a diagram showing a shape for mounting and fixing the optical direction converting optical element 8, and a mounting leg portion 8 e is provided in the portion of the inverted conical surface 8 d, and a part of the leg portion 8 e is a screw or the like. Thus, the shape can be fixed to the mounting substrate 5 or the like. That is, the optical direction converting optical element 8 having an attachment portion for determining the positional relationship with the light source, such as the leg portion 8e, can be provided between the incident surface 8a and the side wall surface 8c.

  FIG. 7 is a view showing a shape for mounting and fixing the optical direction changing optical element 8. The optical direction changing optical element 8 can be fixed to a hole formed in the mounting substrate 5 or the like in the leg portion 8e. The shape has a claw portion 8f. That is, the mounting portion described above can be the optical direction converting optical element 8 having the claw portion 8f for fixing.

  FIG. 8 is a diagram showing a shape for mounting and fixing the light direction changing optical element 8. The light direction changing optical element 8 is located in the region of the inverted conical surface 8d with respect to the external shape of the LED 2 as the light source. And a positioning portion 8g for positioning the optical element 8 for changing the light direction.

  FIG. 9 is a diagram showing the shape of the optical direction changing optical element 8 at the time of manufacturing. The optical direction changing optical element 8 has an injection (injection) molded gate 8h in the region of the inverted conical surface 8d. It is made into a shape. That is, when the optical element 8 for changing the light direction is formed by injection (injection) molding using a resin such as an acrylic resin, a polycarbonate resin, an epoxy resin, or a silicone resin, the gate 8h is set in the region of the inverted conical surface 8d. . The same applies when forming with a glass mold. In addition, a part other than the incident surface 8a, the reflecting surface 8b, and the side wall surface 8c is set so that the divided part (parting line) of the molding die does not affect the optical performance of the optical element 8 for changing the light direction. Is preferred. Further, according to injection molding, a plurality of optical elements for changing light direction 8 can be integrally formed to form an integrated optical element for changing light direction. In other words, the optical direction changing integrated optical element is formed by injection molding, and a plurality of optical direction changing optical elements 8 are integrally formed through an injection molding gate. it can.

  According to the above embodiment, the optical element 8 for changing the light direction can be easily fixed to the mounting substrate 5 or the like, and is particularly effective when formed by injection molding with a resin. In addition, by defining the gate 8h position and the like when forming by injection molding, it is possible to prevent the optical performance from being affected.

(Third embodiment)
FIG. 10 is a diagram showing an embodiment of the optical direction converting optical element 8 showing the third embodiment, in which the shape of the reflecting surface 8b is improved. The central portion 8i of the morning glory shape of the optical element 8 for changing the light direction is a flat surface. FIG. 11 is a diagram showing the morning glory shape with a concave central portion 8i. That is, the central portion of the reflection surface having the morning glory shape of the optical direction conversion optical element 8 is concave or planar, and the optical direction conversion optical element according to claim 1 can be obtained. . FIG. 12 is a diagram showing a configuration in which a metal film 90 such as an aluminum vapor deposition film, a silver sputtered film, or an electroless nickel plating is formed on the morning glory-shaped reflecting surface 8b, that is, the air-side surface portion of the reflecting surface 8b. .

  According to the above-described embodiment, the light beam LB incident from the LED 2 is emitted from the morning glory-shaped central portion 8i with the angle changed by the plane. Further, when the morning glory-shaped central portion 8i is concave, it is emitted at a greatly different angle, and the diffuser plate above the light source can be irradiated. Further, by forming the metal film 90 on the air side surface portion of the reflecting surface 8b, the light beam LB is reflected in the lateral direction even when deviated from the total reflection condition due to the molded state or scratches, etc. It is suitable for application to few thin planar light sources.

(Fourth embodiment)
FIG. 13 shows the light source LED 2 that is incident on the light direction conversion optical element 8 to be emitted in the horizontal direction, and the light emitted from the LED 2 in the horizontal direction is directly passed to the outside without passing through the light direction conversion optical element 8. It is a figure which shows the structure which distributes light. In the light source having the configuration in which the light source lens 2b is provided on the LED 2, the light emitted from the LED 2 is not incident on the optical direction converting optical element 8 and is also emitted in the lateral direction, and all the light is optically converted to the optical direction. If it is made to enter into the element 8, the incident surface 8a will become large and the optical element 8 for light direction conversion will enlarge. Therefore, the light from the LED 2 is incident on the light direction changing optical element 8 through the air layer 80 and is directly emitted to the outside without going through the light direction changing optical element 8. Accordingly, the light emitted from the LED 2 becomes the light LB1 emitted from the optical direction converting optical element 8 and the light LB2 emitted in the lateral direction without entering the optical direction converting optical element 8.

  The light direction converting optical element 8 includes leg portions 8e provided concentrically around the light source center. The leg portion 8e is provided on the surface of the inverted conical surface 8d, and is preferably a whole or a part of a concentric sphere, and preferably has a leg portion or a claw portion so that it can be fixed to the mounting substrate 5 or the like. That is, an attachment portion for determining the positional relationship with the light source, such as a leg portion 8e, is provided between the incident surface 8a and the side wall surface 8c, and this attachment portion is a light direction formed concentrically from the center of the light source. The conversion optical element 8 can be obtained.

  According to the above embodiment, the light from the light source can be emitted in the lateral direction even in the configuration in which the light source lens 2b is provided without increasing the optical element 8 for changing the light direction. Further, since the leg portions 8e are provided in a concentric spherical shape, the components directly distributed from the light source can be prevented from being affected, which is suitable for application to a thin planar light source having little intensity unevenness.

(Fifth embodiment)
FIG. 14 is an overall perspective view of a planar light source device according to the fifth embodiment of the present invention. In the figure, the width direction of the planar light emitting device 1 is the x direction, the length direction is the y direction, and the height direction is the z direction.

(Overall configuration of planar light emitting device 1)
The planar light emitting device 1 is provided on a housing 3 that houses a plurality of light emitting light source units 9 and the light emitted from the plurality of light emitting light source units 9 provided on the inner wall surface of the housing 3. A mirror-like light reflecting portion 4, a mounting substrate 5 on which a plurality of light emitting light source units 9 are mounted, a support plate 6 on which the plurality of mounting substrates 5 are mounted, and a plurality of light sources provided on the light extraction side of the housing 3. And a diffuse transmission part 7 that reflects and diffuses part of the light emitted from the light emission light source unit 9.

  The light emission light source unit 9 includes an LED 2 that is a light source and a light direction changing optical element 8 that is disposed at a predetermined position via an incident layer 80. The light emitted from the LED 2 is emitted obliquely backward, obliquely forward, and laterally mainly by the light emission light source unit 9, and a part thereof is also emitted forward (z direction). Moreover, it may be arranged so as to have a component that distributes light directly from the LED 2 to the outside without using the optical element 8 for light direction conversion. The light emitting light source unit 9 has a surface-mounted LED 2 and is mounted on the mounting substrate 5 and 49 pieces are accommodated in the housing 3. In the present embodiment, the average illuminance of the planar light emitting device 1 is 1000 (lx).

  The housing 3 is a resin housing formed by injection molding a resin material such as polycarbonate, and a support portion for supporting the mounting substrate 5 is provided therein. In addition, it is not limited to a resin housing | casing, A metal housing | casing, such as aluminum, may be sufficient.

  The light reflecting portion 4 has a light reflecting surface 4A formed in a mirror shape by sticking sheet-like aluminum as a means for enhancing the reflectivity of light emitted from the light emitting light source unit 9. In addition, the light reflection part 4 may be formed by methods other than sheet sticking, for example, may be formed by electroless plating or white coating. Further, the light reflecting surface 4A may have a surface state that reflects at least light, other than a mirror surface.

  The mounting substrate 5 is made of a glass epoxy substrate, and has a wiring pattern (not shown) electrically connected to the electrode terminal portion exposed on the bottom surface of the LED 2 on the surface, and a plurality of LEDs 2 are arranged on the surface at a predetermined interval. It is mounted with. Moreover, it is preferable to have a hole for fixing the optical element 8 for changing the light direction with the claw portion 8f or the like corresponding to the plurality of LEDs 2. That is, the light emitting light source unit 9 composed of the LED 2 and the light direction changing optical element 8 mounted as described above is mounted on the mounting substrate 5 at a predetermined interval.

  The support plate 6 is mounted with a mounting substrate 5 on which a plurality of light emission light source units 9 are mounted at a predetermined interval, whereby the intervals in the x and y directions of adjacent light emission light source units 9 are constant. Is set to be In the present embodiment, the light emitting light source unit 9 is mounted so that the distance between the x direction and the y direction is 50 mm. Further, the surface of the support plate 6 and the surface of the mounting substrate 5 are painted white in order to enhance the reflectivity of the light emitted from the light emitting light source unit 9.

  The diffuse transmission part 7 is formed in a milky white thin plate shape in which light diffusing particles are mixed with a resin material, and has a predetermined distance in the optical axis direction, that is, the z direction from the light emitting surface of the light emitting light source unit 9. The light emitted from the plurality of light emitting light source units 9 is mixed by transmitting a part of the light, reflecting a part of the light, and reflecting the light within the housing 3. In the present embodiment, the distance from the light emission surface of the light emission light source unit 9 to the diffuse transmission part 7 is 20 mm.

(Operation of the planar light emitting device 1)
The operation of the planar light emitting device 1 will be described below. First, light is emitted by energizing the LEDs 2 of each light emitting light source unit 9 at 50 mA from a power source (not shown). The light emitted from each light emitting light source unit 9 is emitted obliquely backward, obliquely forward, laterally, and partly forward (z direction). There is also a component in which light is directly distributed to the outside from the LED 2 without using the optical element 8 for changing the light direction. Further, there is also light that is reflected without being transmitted even when it reaches the diffuse transmission part 7. In this way, light is mixed in a complicated manner in the space in the housing 3 so that light having an intensity corresponding to the degree of mixing is uniformly radiated from the diffuse transmission part 7 serving as a light emitting surface. At this time, the light source image of each light emission light source unit 9 is at a level where it cannot be visually recognized.

(Effect of 5th Embodiment)
According to the fifth embodiment described above, since light is collected from a plurality of light emission light source units 9 at any one point on the light emitting surface and mixed, the surface emission of light is performed. The light emission amount variation and color variation as the single characteristics of the radiation light source unit 9 are averaged, and the planar light emitting device 1 with less unevenness in light emission and less color unevenness can be obtained without increasing the number of light sources with respect to the light emission area. It is done. Therefore, even if there is a light emission light source unit 9 that is turned off due to a failure or the like, the light is supplemented by another light emission light source unit 9 that is turned on, so that the illuminance is reduced and unevenness in light emission is suppressed. be able to.

  Further, since the light emission light source units 9 are dispersed in a predetermined arrangement with respect to the light emitting surface, and the light emitting characteristics of the planar light emitting device 1 are less likely to vary due to variations and changes in the single unit characteristics, color unevenness, light emission Even if the uneven light emission light source unit 9 is within an allowable range, there is no difference in the light emission characteristics of the planar light emitting device 1, and it can be manufactured at low cost and a plurality of planar light emitting devices 1. Even if it is used in combination, visual discomfort does not occur.

  Moreover, the light emission light source unit 9 may have a plurality of integrated shapes. Further, the shape of the planar light emitting device 1 is not limited to the flat shape described above, and may be, for example, the planar light emitting device 1 in which the diffuse transmission part 7 has a gently curved surface.

  The light color is not particularly limited, and may be white, red, green, or blue, or any color obtained by mixing these colors.

  Further, in the planar light emitting device 1 having white light, the generation of white light is not limited to the one generated by mixing RGB light in the package of the LED 2, for example, a red LED on the mounting substrate 5. Alternatively, a green LED and a blue LED may be arranged, and white light may be generated by mixing light emitted from each of the LEDs in the diffuse transmission unit 7.

  Also, for the generation of white light by mixing blue light and yellow light, the blue LED element and the yellow phosphor are not provided in the same package of the LED 2, for example, a thin film-like yellow phosphor on the back surface of the diffuse transmission portion 7. May be applied to generate white light based on the transmission of blue light. Alternatively, an ultraviolet light emitting LED may be used, and a thin-film RGB phosphor may be applied to the back surface of the diffuse transmission part 7 to generate white light.

(Sixth embodiment)
In the sixth embodiment, the arrangement of the support plate 6 and the light emitting light source unit 9 is devised in the fifth embodiment to make it suitable for thinning and high output. . FIG. 15 is a diagram showing a configuration in which the light emitting light source unit 9 is mounted on the mounting substrate 5 via a spacer 5S having a predetermined height. The light emitted obliquely rearward is reflected and diffused by the surface of the support plate 6 and the surface of the mounting substrate 5 at a portion away from the light source. FIG. 16 is a diagram showing a configuration in which the reflecting mirror portion M is arranged on the surface of the mounting substrate 5 or the support plate 6 around the light emitting light source unit 9. The reflecting mirror part M may be formed on a part of the mounting substrate 5 or the support plate 6 or may be disposed on the surface of the mounting substrate 5 or the support plate 6 as an independent reflecting mirror. Good.

  That is, a planar light emitting device including a housing, wherein the light emitting light source unit is disposed on the front side of the back reflecting portion provided in the housing. Can do. In addition, the planar light emitting device includes a casing, and the casing includes a reflecting mirror that reflects light emitted from the light source unit for light emission toward the diffuse transmission unit. A light-emitting device can be obtained.

  Since the light emitted from the light emission light source unit 9 is reflected forward, the configuration in which a large number of light emission light source units 9 are arranged at a short pitch is particularly effective. According to the embodiment with the configuration of FIGS. 15 and 16, in addition to the fifth embodiment, there is an effect that a configuration that is particularly suitable for thinning and high output can be achieved.

(Seventh embodiment)
FIG. 17 is a plan view of a planar light emitting device having a different arrangement of the light emitting light source unit 9 according to the fifth embodiment. In the following description, parts having the same configuration and function as those of the fifth embodiment are denoted by common reference numerals. Further, in the same figure, illustration of the diffuse transmission part 7 described in FIG. 14 is omitted.

  In this planar light emitting device 1, the arrangement of the light emitting light source unit 9 is different from the regular square shape shown in FIG. Thus, the arrangement of the light emission light source units 9 is not limited to a regular square shape, and may be other arrangements such as a staggered arrangement, a regular triangle shape, a rectangular shape, or an isosceles triangle shape.

(Eighth embodiment)
FIG. 18 is a partial plan view of the planar light emitting device according to the eighth embodiment. In the drawing, the diffusion / transmission part 7 covering the opening of the housing 3 is not shown for easy explanation.
In the planar light emitting device 1, light emitting light source units 9R (red), 9G (green), and 9B (blue) having different emission colors are regularly arranged.

(Effect of 8th Embodiment)
According to the eighth embodiment described above, even in the case where the light emission light source units 9R, 9G, and 9B having different emission colors are regularly arranged on the support plate 6, they are within the space of the housing 3. By mixing the three primary colors of RGB, uniform white light can be emitted in a planar shape. The emission intensity of the light emission light source units 9R, 9G, and 9B may be varied as long as it is within a predetermined allowable range, and the arrangement of LEDs that generate colors other than white is possible. It is also good.

It is the figure which showed the optical element for light direction conversion and light source which show 1st Embodiment. It is a figure for demonstrating the total reflection in the reflective surface 8b. It is a figure for demonstrating the shape of the reflective surface 8b formed in the upper surface of the optical element 8 for light direction conversion. It is a figure which shows the directivity of the light ray radiate | emitted from the optical element 8 for light direction conversion which concerns on 1st Embodiment. It is the optical element 8 for light direction conversion which shows 2nd Embodiment, Comprising: It is a figure which shows embodiment when a mounting is considered. It is a figure which shows the shape for attachment fixation of the optical element 8 for light direction conversion. It is a figure which shows the shape for attachment fixation of the optical element 8 for light direction conversion. It is a figure which shows the shape for attachment fixation of the optical element 8 for light direction conversion. It is a figure which shows the shape at the time of manufacture of the optical element 8 for light direction conversion. It is the optical element 8 for light direction conversion which shows 3rd Embodiment, Comprising: It is a figure which shows embodiment which improves the shape of the reflective surface 8b. It is a figure which shows what made the central part 8i of the morning glory shape concave. It is a figure which shows the structure which formed metal films 90, such as an aluminum vapor deposition film, a silver sputtering film, electroless nickel plating, for example in the air side surface part of the reflective surface 8b. A structure in which light emitted from the LED 2 as a light source is incident on the light direction conversion optical element 8 and emitted in the horizontal direction, and light emitted from the LED 2 in the horizontal direction is directly distributed to the outside without passing through the light direction conversion optical element 8. FIG. It is a whole perspective view of the planar light source device which concerns on the 5th Embodiment of this invention. It is a figure which shows the structure which mounts the light source unit 9 for light emission on the mounting board | substrate 5 via the spacer 5S which has predetermined | prescribed height. It is a figure which shows the structure which has arrange | positioned the reflective-mirror part M on the surface of the mounting board | substrate 5 or the support plate 6 around the light source unit 9 for light emission. It is a top view of the planar light-emitting device from which arrangement | positioning of the light emission light source unit 9 which concerns on 5th Embodiment differs. It is a fragmentary top view of the planar light-emitting device concerning an 8th embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Planar light-emitting device, 2 ... LED, 2a ... Light emission part, 3 ... Case, 4 ... Light reflection part, 4A ... Light reflection surface, 5 ... Mounting board, 6 ... Support plate, 7 ... Diffuse transmission part, 8 DESCRIPTION OF SYMBOLS Optical direction converting optical element, 8a ... Incident surface, 8b ... Reflecting surface, 8c ... Side wall surface, 9 ... Light source unit for light emission, 80 ... Incident layer, 90 ... Metal film

Claims (12)

  Refracting the light reflected from the reflecting surface, the incident surface from which the light emitted from the light source is incident through the incident layer, the reflection surface having a morning glory shape that reflects the light incident from the incident surface, and An optical element for changing light direction, comprising a side wall surface that emits in a side surface direction.   The optical element for redirecting light according to claim 1, wherein the incident layer is air.   The optical element for changing light direction according to claim 1, wherein the reflecting surface totally reflects light incident from the incident surface.   The optical element for changing light direction according to claim 1, wherein the reflection surface having the morning glory shape has a metal film on a surface thereof.   The optical element for changing the direction of light according to claim 1, wherein the reflection surface having the morning glory shape has a size that reflects all light incident from the incident surface.   2. The optical element for changing light direction according to claim 1, wherein the side wall surface is 25% or more of the total length of the optical element for changing light direction.   The light direction changing optical element according to claim 1, wherein the light emitted from the side wall surface is directed forward or backward from the horizontal direction.   8. The optical element for changing light direction according to claim 1, wherein the optical element is formed by injection molding and has the injection molding gate between the incident surface and the side wall surface.   8. A light direction change, wherein the light direction changing optical element is formed by injection molding, and the plurality of light direction changing optical elements according to claim 1 are integrally formed through the injection molding gate. Integrated optical element. A light source;
9. A light source unit for light emission, comprising: the light direction converting optical element according to claim 1 disposed at a predetermined position with respect to the light source via an incident layer. 11. The light emission light source unit according to claim 10, a light reflection part that reflects light emitted from the light emission light source unit, and a diffusion transmission part that diffuses and transmits the light to emit planarly. And
The planar light-emitting device, wherein the diffuse transmission unit emits light having an intensity obtained based on a mixture of light emitted from the light emitting light source unit. 11. The light emission light source unit according to claim 10, a light reflection part that reflects light emitted from the light emission light source unit, and a diffusion transmission part that diffuses and transmits the light to emit planarly. And
The planar light emitting device, wherein the diffuse transmission unit emits light of a color obtained based on a mixture of light emitted from the light emitting light source unit.

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