JP6386142B2 - Lighting device - Google Patents

Description

  The present invention relates to a lighting device.

  In recent years, LEDs (Light Emitting Diodes) have been increasingly used as light sources for lighting devices. LEDs are beginning to be used in place of fluorescent tubes as light sources for indoor lighting fixtures that are mounted on the ceiling. The LED is characterized by being mercury-free, and is an environmentally friendly light source.

  An illuminating device using an LED may impart directivity to light emitted from the LED. Patent Document 1 and Patent Document 2 disclose optical systems in which directivity is imparted to light emitted from an LED.

JP 2010-198919 A JP 2007-48740 A

  For example, a type of indoor lighting fixture in which an LED is used as a light source and attached to the ceiling has a problem that the light distribution of light emitted from the fixture is narrower than a type of indoor lighting fixture in which a fluorescent tube is used as a light source and attached to the ceiling. In particular, there is a problem that there is little indirect light because there is little light toward the ceiling. Since Patent Documents 1 and 2 do not consider this problem, it is considered that sufficient light distribution characteristics cannot be improved. An object of the present application is to increase indirect light in an indoor lighting fixture of a type in which an LED is used as a light source, for example, attached to a ceiling.

  Means for solving the problems of the present invention are as follows, for example.

A first LED light source and a second LED light source mounted on a substrate, an electrode on the substrate so as to surround a center of a lighting device, and a first optical member corresponding to the first LED light source; A lighting device comprising: a second optical member corresponding to the second LED light source; and a composite optical member having an optical member connecting portion connecting the first optical member and the second optical member. The luminous intensity distribution of the emitted light from the first optical member is different from the luminous intensity distribution of the emitted light from the second optical member, and the direction in which the illumination device mainly emits light is the front direction, The first LED light source and the second LED light source are front-emitting LED light sources that mainly emit light in the normal direction of the substrate when the side direction is substantially perpendicular to the front direction. The second LED light source is the first LED. The light intensity distribution of the emitted light of the second optical member in the cross section including the center of the second optical member is disposed at a position farther from the center of the illumination device than the source. wider than the luminous intensity distribution of the outgoing light of the first optical member in the section including the center member, the second optical member Ri lens der luminous intensity of the light emitted outermost optical member in the composite optical element The illumination device has a wider distribution than the luminous intensity distribution of the emitted light from the innermost optical member .

  The indirect light of a lighting fixture can be increased by this invention. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

The front view for demonstrating the structure of the illuminating device which concerns on the 1st Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 1st Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 1st Embodiment of this invention. The figure for demonstrating the LED light source which concerns on the 1st Embodiment of this invention. The figure for demonstrating the LED light source which concerns on the 1st Embodiment of this invention. The figure for demonstrating the LED light source which concerns on the 1st Embodiment of this invention. The figure for demonstrating the LED light source which concerns on the 1st Embodiment of this invention. The figure for demonstrating the LED light source which concerns on the 1st Embodiment of this invention. The figure for demonstrating the LED light source which concerns on the 1st Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 1st Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 1st Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 1st Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 1st Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 2nd Embodiment of this invention. The figure for demonstrating the subject which the illuminating device which concerns on the 2nd Embodiment of this invention solves. The figure for demonstrating the subject which the illuminating device which concerns on the 2nd Embodiment of this invention solves. The figure for demonstrating the subject which the illuminating device which concerns on the 2nd Embodiment of this invention solves. The figure for demonstrating the subject which the illuminating device which concerns on the 2nd Embodiment of this invention solves. The figure for demonstrating the subject which the illuminating device which concerns on the 2nd Embodiment of this invention solves. The figure for demonstrating the subject which the illuminating device which concerns on the 2nd Embodiment of this invention solves. The figure for demonstrating the subject which the illuminating device which concerns on the 2nd Embodiment of this invention solves. The figure for demonstrating the subject which the illuminating device which concerns on the 2nd Embodiment of this invention solves. The figure for demonstrating the structure of the illuminating device which concerns on the 2nd Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 2nd Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 2nd Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 2nd Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 3rd Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 4th Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 5th Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 5th Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 5th Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 1st Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 1st Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 1st Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 2nd Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 2nd Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 2nd Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 2nd Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 2nd Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 6th Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 6th Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 6th Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 7th Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 7th Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 7th Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 7th Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 7th Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 7th Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 7th Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 7th Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 7th Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 7th Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 7th Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 7th Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 7th Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 7th Embodiment of this invention. Sectional drawing for demonstrating the structure of the illuminating device which concerns on the 7th Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 7th Embodiment of this invention. The figure for demonstrating the structure of the illuminating device which concerns on the 7th Embodiment of this invention.

  Hereinafter, the present invention will be described with reference to the drawings.

  FIG. 1 is a front view for explaining the configuration of the illumination device according to the first embodiment of the present invention, as viewed from the normal direction of the substrate 2 on which the LED light sources 3A and 3B are mounted. In the substrate 2, a surface on which the LED light sources 3A and 3B are mounted is referred to as a mounting surface. FIG. 1 is a front view for explaining the arrangement of the LED light source 3A and the LED light source 3B and the outline of the composite optical member 7, and members not related to the description are omitted. 2 is a cross-sectional view taken along the line AA ′ of FIG. The said cross section is a surface parallel to the normal line of the board | substrate 2 with which LED light source 3A and LED light source 3B are mounted. Also in FIG. 2, only main members are shown.

  The LED light sources 3A are arranged on the inner side (side closer to the center C) than the LED light sources 3B, are scattered radially from the center C of the lighting device 1, and are arranged so as to surround the center C. The LED light source 3 </ b> B is arranged on the outermost periphery so as to surround the center C.

  The LED light source 3A will be described in detail with reference to FIGS. 4 (a) and 4 (b). 4A is a view of the LED light source 3A viewed from the normal direction of the substrate 2, and FIG. 4B is a cross-sectional view taken along the line CC ′ of FIG. 4A. As an example of the LED light source, a case where a white LED module using a blue light emitting LED and a yellow phosphor is used will be described. The present invention is not limited to the configurations such as the emission spectrum and shape of the LED, the number of LEDs included in the LED light source, the number of types, and the presence / absence and type of phosphors, the number of types of phosphors included in the LED light source.

  In the LED light source 3A, the LED 30 is mounted on a mounting surface 37a of a frame body 37 made of white resin or the like. In this example, the negative electrode 31 is mounted on the mounting surface 37a of the frame, and the LED 30 is mounted thereon. The LED 30 is electrically connected to the negative electrode 31 and the positive electrode 32 by a wire 35. Inside the frame 37, together with the LED 30, a phosphor 33 that absorbs part of the light from the LED 30 and converts the absorbed light into light having a longer wavelength is sealed with a sealing resin 34 such as silicone. Has been.

  Since the light emitting surface 3AE is a surface that emits light in the LED light source 3A, it can be defined as a surface that the side wall 37b of the frame 37 surrounds. However, since the frame 37 transmits part of light, light leaks from the entire frame. However, most of the light is emitted from the light emitting surface 3AE.

  The reason why the light emitting surface 3AE is defined as the surface surrounded by the side wall 37b of the frame body 37 is as follows. A part of the light emitted from the LED 30 is absorbed / scattered / transmitted / reflected by the phosphor 33, and part of the light is Fresnel-reflected at the interface between the sealing resin 34 and the air to return light, and further part Exits from the sealing resin 34 as emitted light. The emitted light from the LED 30 is repeatedly reflected and scattered, and spreads over the entire region surrounded by the side wall 37b of the frame 37. The emitted light from the LED 30 spreading over the entire region excites the phosphor 33 dispersed throughout the region to cause the phosphor to emit light. In this way, light is emitted from the entire region. Therefore, the light emitting surface 3AE is defined as a surface surrounded by the side wall 37b of the frame body 37. However, the light emission intensity in the vicinity of the LED 30 is the highest on the light emitting surface 3AE.

  Outside the frame body 37, there are mounting terminals 36 and mounting terminals 36 ′ on the substrate 2 of the LED light source 3 </ b> A that are electrically connected to the negative electrode 31 and the positive electrode 32, respectively. The mounting terminal 36 and the mounting terminal 36 ′ are electrically connected to the electrode 40 and the electrode 40 ′ wired on the substrate 2.

  The feature of the LED light source 3 </ b> A in this embodiment is that light is mainly emitted in the normal direction of the substrate 2. To mainly emit light means to emit a large amount of light in a direction within a polar angle of ± 90 degrees when the angle from the normal is a polar angle with the normal of the substrate 2 as the center. In many cases, the angle at which the luminous intensity of the LED light source is maximized may be approximately equal to the normal direction of the substrate 2 or within a polar angle of ± 20 degrees. The LED 30 is mounted on a surface substantially parallel to the substrate 2 on which the LED light source 3A is mounted. Moreover, it has a light emitting surface substantially parallel to the substrate 2 on which the LED light source 3A is mounted. Hereinafter, at least an LED light source having any of these characteristics will be referred to as a front-emitting LED light source. This LED light source 3A is a so-called top view type LED light source.

  In most cases, the luminous intensity distribution of the emitted light from the front-emitting LED light source is Lambertian (the angle θ from the normal, the luminous intensity (radiant intensity) I (θ), and the normal direction in the normal direction of the mounting surface. The relationship with the luminous intensity (radiation intensity) I (0) is as follows: I (θ) = I (0) cos θ). The LED light source 3A is provided with an isotropic lens centered on the LED light source 3A as viewed from the front as the first optical member 5 (see FIG. 1). Here, the lens is not limited to being isotropic with respect to the center of the LED light source 3A.

  The LED light source 3B will be described in detail with reference to FIGS. 5 (a) to 5 (d). 5A is a view of the LED light source 3B viewed from the normal direction of the substrate 2, and FIG. 5B is a view of the LED light source 3B as indicated by an arrow E in FIG. 5A. It is the figure seen from the direction which opposes the light emission surface 3BE. FIG.5 (c) is the figure which looked at the side surface of LED light source 3B like the arrow F of Fig.5 (a). FIG.5 (d) is DD 'sectional drawing of FIG.5 (b). As an example of the LED light source, a case where a white LED module using a blue light emitting LED and a yellow phosphor is used will be described. The present invention is not limited to the configurations such as the emission spectrum and shape of the LED, the number of LEDs included in the LED light source, the number of types, and the presence / absence and type of phosphors, the number of types of phosphors included in the LED light source.

  In the LED light source 3B, the LED 30 is mounted on the mounting surface 37a of the frame body 37 (see FIG. 5D). In this example, the negative electrode 31 is mounted on the mounting surface 37a of the frame, and the LED 30 is mounted thereon. The LED 30 is electrically connected to the negative electrode 31 and the positive electrode 32 by a wire 35. Inside the frame 37, together with the LED 30, a phosphor 33 that absorbs part of the light from the LED 30 and converts the absorbed light into light having a longer wavelength is sealed with a sealing resin 34 such as silicone. Has been.

  Similar to the light emitting surface 3AE of the LED light source 3A, the light emitting surface 3BE of the LED light source 3B is a surface that emits light in the LED light source 3B, and thus can be defined as a surface surrounded by the side wall 37b of the frame body 37 (FIG. 5). (See (b) and FIG. 5 (d)). The reason for the definition is the same as the reason described when defining the light emitting surface 3AE of the LED light source 3A. However, since the frame 37 transmits part of light, light leaks from the entire frame. In particular, light leaks from a portion where the frame 37 is thin. However, most of the light is emitted from the light emitting surface 3BE.

  Outside the frame body 37, there are mounting terminals 36 and mounting terminals 36 ′ on the substrate 2 of the LED light source 3 </ b> B that are electrically connected to the negative electrode 31 and the positive electrode 32, respectively. The mounting terminal 36 and the mounting terminal 36 ′ are electrically connected to the electrode 40 and the electrode 40 ′ wired on the substrate 2.

  The feature of this LED light source 3B is that the LED 30 is mounted on a surface substantially perpendicular to the substrate 2 on which the LED light source 3B is mounted. In other words, the LED 30 is mounted on a surface substantially perpendicular to the mounting terminal 36. It can also be said that the LED 30 is mounted on a surface that is not parallel to the substrate 2, that is, has a tilt with respect to the substrate 2. It can also be said that the LED 30 is mounted at a different angle from the front light emitting LED light source 3A. Another feature is that it has a light emitting surface substantially perpendicular to the substrate 2 on which the LED light source 3B is mounted. This may be paraphrased as having a light emitting surface substantially perpendicular to the mounting terminal 36. It can also be said that the light emitting surface is arranged at a different angle from the front light emitting LED light source 3A. Further, it can be said that the light-emitting surface is not parallel to the substrate 2, that is, has an inclination with respect to the substrate 2. Further, it is said that light is mainly emitted in a direction that is not parallel to the normal line of the substrate 2, that is, a direction that is inclined with respect to the normal direction of the substrate 2 (this direction is referred to as a side emission central direction). Also good. Light is mainly emitted in many directions in which the angle from the side emission center direction is within ± 90 degrees centering on the side emission center direction (in this example, a direction substantially perpendicular to the normal line of the substrate 2). Means emitting light. In many cases, the angle at which the luminous intensity of the LED light source is maximized may be substantially equal to the side emission center direction, or the angle from the side emission center direction may be within ± 20 degrees.

  Hereinafter, at least an LED light source having any of these characteristics will be referred to as a side-emitting LED light source. The LED light source 3B is a so-called side view type LED light source.

  However, the LED light source may be tilted in a range of variation depending on mounting conditions. Therefore, the angle formed by the substrate 2 on which the LED light source 3B is mounted, the surface on which the LED 30 is mounted, and the substrate 2 and the light emitting surface may deviate from 90 degrees. The deviation of the angle from 90 degrees is preferably within ± 20 degrees, and more preferably within ± 5 degrees.

  In FIG. 1, the normal line of the light emitting surface 3BE of the LED light source 3B is directed to the outside in the mounting surface (the direction from the center C to the outside), and the main light emitting direction is the outside in the mounting surface. In most cases, the luminous intensity distribution of the emitted light is Lambertian that maximizes the normal direction of the light emitting surface 3BE of the LED light source 3B. A second optical member 6 is disposed corresponding to the LED light source 3B. The light incident surface 6BE of the second optical member 6 is disposed so as to face the light emitting surface 3BE of the LED light source 3B, and the light guided through the second optical member 6 toward the outside in the mounting surface is the exit surface. 6B is emitted into the air. The entrance surface 6 </ b> A and the exit surface 6 </ b> B are substantially perpendicular to the substrate 2. That is, in the cross section parallel to the normal line of the substrate 2 on which the LED light source corresponding to the second optical member 6 is mounted, the shapes of the incident surface and the exit surface of the second optical member are linear.

  The first optical member 5 and the second optical member 6 are connected by the optical member connecting portion 4 to form a composite optical member 7. In the present embodiment, all the optical members are collectively molded and connected by the optical member connecting portion 4. In this example, the composite optical member 7 is made of a resin such as polycarbonate, polystyrene, or acrylic.

  This will be described in more detail using the cross-sectional shape of FIG. As indicated by an arrow in FIG. 2, a direction in which the illumination device 1 mainly emits light is a front direction Z. The direction in which the lighting device 1 mainly emits light is, for example, a type of lighting device that is installed on the ceiling and illuminates the interior of the room, or the direction normal to the ceiling or the direction from the ceiling to the floor (directly below the lighting device 1). Direction) is the front direction Z. Furthermore, the direction in which the light distribution characteristic (luminous intensity distribution) is substantially maximum may be the front direction Z.

An in-plane direction substantially perpendicular to the front direction Z is defined as a side surface direction. In the present embodiment, since the normal direction of the mounting surface of the substrate 2 is parallel to the front direction Z, the in-mounting surface direction and the side surface direction are the same direction.
When the normal of the mounting surface of the substrate 2 is inclined from the front direction Z, the mounting surface inward direction and the side surface direction are different directions.

The lighting device 1 has a frame 11 as a housing, and the frame 11 is made of, for example, iron.
The substrate 2 is attached to a part of the flat surface 11A of the frame 11 by screws or the like. The frame 11 has a hollow portion, and a lighting circuit 9 for driving the LED light source 3A and the LED light source 3B is installed in the hollow portion. The frame 11 is bent and inclined near the end 2E of the substrate 2 and has an inclined portion 11B. A diffusion cover 8 is attached to the frame 11.

The lighting device 1 is fixed to the ceiling 50 by a fixture 51. Due to the fixture 51, the LED light source 3 cannot be placed in the center of the lighting device 1. The center cover 10 is installed on the front side of the fixture 51 so that light does not enter the groove where the fixture 51 is arranged.
The light propagating toward the groove is reflected and scattered in the front direction by the center cover 10. The center cover 10 is preferably a member having a high reflectance. Furthermore, since the inside of the substrate 2 and the frame 11 is covered with a white material using white paint, white resist, white sheet, or the like, the center cover 10 is also preferably a member that scatters white.

  In this example, the diffusion cover 8 has a shape that covers all the LED light sources 3 and diffuses and reflects and transmits light emitted from the LED light sources 3. For the sake of explanation, the diffusion cover 8 is divided into a front part 8A in which the normal line of the surface of the diffusion cover 8 is approximately directed in the front direction Z, and a side part in which the normal line of the surface of the diffusion cover 8 is approximately directed in the lateral direction. Roughly divided into 8B. The diffusion cover 8 is often a resin, and contains a diffusion material such as silica in the resin. The total light transmittance of the diffusion cover 8 can be controlled by the type and concentration of the diffusion material. The light incident on the diffusion cover 8 exits the illumination device 1 from the diffusion cover 8 with a certain scattering angle distribution. In the present invention, the shape of the diffusion cover 8 is not limited and may be a shape that does not cover all the LED light sources, and the diffusion cover may not be provided with the entire area.

  The scattering angle distribution is generally different between transmitted light and reflected light. The scattering angle distribution of the transmitted light directly affects the light distribution as the illumination device. While the light distribution of the lighting device (lighting fixture) is expressed in terms of luminous intensity, the scattering angle distribution can be discussed by dividing the luminance of the target surface element by the total luminous flux emitted from the surface element. Since there are many, the scattering angle distribution will be described using a scattered transmission distribution (BTDF).

  The scattered light scattering characteristics of the diffusion cover 8 will be described with reference to FIG. FIG. 3 shows a state in which the light ray RAYI is incident on the incident surface 8SI of the surface element with the diffusion cover 8 at the incident angle θi, and the light ray RAYO is emitted from the emission surface 8SO with a certain scattered transmission luminance distribution. The incident angle θi and the outgoing angle θo are angles with reference to the normal 8N of the surface element.

  When the total light transmittance of the diffusing cover 8 is low, the exit surface of the diffusing cover 8 is a completely diffusing surface where the scattered transmission luminance distribution is uniform in any direction no matter what angle the light enters the diffusing cover 8. It becomes a surface close to.

  As the total light transmittance of the diffusing cover 8 becomes higher, the scattered transmission luminance distribution has a peak at an exit angle θo equal to the incident angle θi.

  In FIG. 2, the light incident on the front portion 8 </ b> A of the diffusion cover is emitted in a range of ± 90 degrees centering on a polar angle of 0 degrees when the angle from the front direction Z is a polar angle. The luminous intensity distribution from the front portion 8A of the diffusion cover has a peak at a polar angle of approximately 0 degrees. The light incident on the side surface portion 8B of the diffusion cover is emitted in a range of ± 90 degrees with a polar angle of 90 degrees as the center. The luminous intensity distribution from the side surface portion 8B of the diffusion cover has a peak at a polar angle of 90 degrees.

  In most cases, since the front portion 8A has a larger area than the side portion 8B, the range of the light distribution characteristic of the lighting device 1 from the polar angle 0 to approximately ± 70 degrees is the emission intensity distribution of the front portion 8A. Strongly dependent. The range of the light distribution characteristic of the illumination device 1 from approximately 80 to 180 degrees and approximately from −80 to −180 degrees is strongly dependent on the emitted light intensity distribution of the side surface portion 8B.

  When only the front light emitting LED light source is used, a lot of light is incident on the front portion 8A, so that the floor directly under the lighting device 1 becomes brighter and the incident light on the side surface portion 8B is less. There is little light on the floor, walls and ceiling. Therefore, there is a problem that the corner of the room is not sufficiently bright and there is little indirect light.

  In order to solve this problem, it is conceivable to increase the amount of light emitted from the LED light source toward the side surface portion 8B. However, the side surface portion 8B has a small area and is positioned on the outermost side of the illumination device. Therefore, the LED light source on the substrate 2 is smaller than the front portion 8A and must irradiate light toward a certain distance. Increasing the luminous flux incident on the side surface 8B is one of the specific objects of the present invention.

  The effect of increasing the amount of light incident on the side surface portion 8B can also be obtained by spreading the light from the front light emitting LED light source using a wide-angle lens. However, the light from the LED light source located on the inner side in the in-plane direction of the substrate 2 spreads until the light reaches the side surface portion 8B, and the light cannot be sufficiently irradiated. Therefore, a greater effect can be obtained by irradiating the side surface portion 8B with the LED light source closest to the side surface portion 8B.

  Even in this case, it is difficult to direct most of the light from the front light-emitting LED light source to the side surface portion 8B, and often involves light loss. This is because the luminous intensity distribution of the front light emitting LED is approximately isotropic in the direction of the light emitting surface, and about half of the light is emitted in the direction opposite to the side surface portion 8B. Therefore, much light must be reflected and refracted by 90 degrees or more toward the side surface portion 8B. This is because such an optical member is often complicated and large-scale and often involves many losses. Although it is conceivable to increase only the LED light source closest to the side surface portion 8B, it is often impossible to take a space for arranging a sufficient number of LEDs.

  Therefore, the lighting device 1 in the present embodiment uses a side-emitting LED light source as the LED light source 3B closest to the side surface 8B, and guides light from the side-emitting LED light source 3B to the vicinity of the side surface 8B. A second optical member 6 is provided. By using a side-emitting LED light source as the LED light source 3B closest to the side surface portion 8B, most of the light is emitted in the side surface direction. Further, in order to directly irradiate the side surface portion 8B having a small area, the second optical member 6 having the light guide portion is used to guide the light emitted from the side light emitting LED light source and emit light near the side surface portion 8B. The configuration.

  The optical system will be described in detail with reference to FIG. 6A is an enlarged view of a part of the AA ′ cross section in FIG. 1, and FIG. 6B is a cross sectional view along the BB ′ line in FIG. The first optical member 5 and the second optical member 6 are connected by the optical member connecting portion 4. The height 4H of the optical member connecting portion is smaller than the height 5H of the first optical member and the height 6H of the second optical member. The first optical member 5 and the second optical member 6 must be higher than the LED light sources 3A and 3B. The height 4H of the optical member connecting portion is set low so as not to block the emitted light from each optical member. Moreover, the composite optical member 7 can be reduced in weight by making the height 4H of the optical member connecting portion lower than that of the first optical member 5 or the second optical member 6. For example, when the height of the front light emitting LED light source 3A is about 1 mm and the height of the side light emitting LED light source 3B is about 1.5 mm, the height 5H of the first optical member is about 5 mm, The height 6H of the second optical member is about 3 mm, and the height 4H of the optical member connecting portion is about 1.5 mm.

  The lens of the first optical member 5 is a wide-angle lens (a lens that spreads light at a wider angle than a spherical lens) that receives light from a spherical incident surface 5A and emits light from an aspherical emission surface 5B. There are two reasons why the wide-angle lens is used as the lens of the first optical member 5. First, when the total light transmittance of the diffusion cover 8 is high (for example, greater than 50%), if the incident angle to the front portion 8A of the diffusion cover 8 is large, the transmitted light of the front portion 8A is also incident. This is because the light distribution as the illuminating device 1 becomes wide because of the scattered transmission luminance distribution having a peak at. Second, when light is emitted at a wide angle and the illuminance of the diffusion cover 8 becomes uniform, the light emission position distribution from the diffusion cover 8 also becomes uniform. When the diffusing cover 8 is shining uniformly, the appearance of the lighting device 1 also looks soft and gives a beautiful impression to the user. Further, since it is not bright locally, the glare is reduced. Therefore, making the illuminance of the diffusing cover 8 uniform is one problem in the optical design of the illumination device.

  The ray RAY20 is described as an example of ray tracing. The light incident on the incident surface 5A from the center of the lens travels straight to the exit surface 5B without being refracted, and has a wide angle at the exit surface 5B (in this case, an angle direction with a large angle from the normal of the lens mounting surface (in this case, the side surface direction)). ) Is refracted and emitted. Actually, since the light emitting surface 3AE has a width, there is emitted light from other than the center of the lens, and the emitted light undergoes some refraction at the incident surface 5A. Since the entrance surface 5A is spherical, the aspheric exit surface 5B can be designed on the assumption that light propagates from the center of the lens. As long as the refraction at the incident surface 5A is not considered, the refraction direction of the light beam can be easily designed and controlled with high accuracy.

  In addition, since the light emitting surface 3AE described above has a width, in order to reduce the influence of refraction generated on the incident surface 5A, it is preferable that the incident surface 5A has a spherical surface as large as possible, and more than half the width of the light emitting surface 3AE. Should be a spherical surface with a large radius. In the case of a spherical surface, it does not affect the optical system as much as it is increased. Therefore, it is preferable to reduce the weight by making the entrance surface 5A as large a spherical surface as possible and reducing the thickness of the lens. From the viewpoint of moldability, it is desirable that the lens thickness is about 1.0 mm or less. That is, it is preferable that the radius of the spherical surface is larger than half of the width of the light emitting surface 3AE and the radius of the lens is larger than 1.0 mm.

  As shown in FIG. 6A, the second optical member 6 receives light from the incident surface 6A and the incident surface 6A ′, and the incident light guides the light from the light guide portion 6L and transmits light from the output surface 6B. Exit. As an example of ray tracing, RAY2, RAY3, and RAY4 are shown in the figure. RAY2 indicates a light beam that is incident from the incident surface 6A 'and reflected from the prism surface 6C described later and emitted from the output surface 6B. RAY3 and RAY4 are light beams that are incident from the incident surface 6A and are emitted from the output surface 6B. The main propagation direction of both the light beams is the lateral outer side direction X, but RAY3 is a light beam that is emitted toward the front direction Z. RAY4 indicates a light beam that is emitted in a direction opposite to the front direction Z and in a direction with the ceiling. As shown in FIG. 2, the light emitted from the emission surface 6 </ b> B directly illuminates the side surface portion 8 </ b> B of the diffusion cover 8. Therefore, by using the second optical member 6 having the light guide portion 6L corresponding to the side-emitting LED light source 3B, the side portion 8B can be directly irradiated, and the indirect light of the lighting device 1 can be increased. It becomes possible. Furthermore, since the present configuration has almost no loss in the light guide section 6L, the light is emitted from the LED light source in a different manner from the present configuration, and then repeatedly reflected and scattered by the substrate 2 and the diffusion cover 8 to propagate the side surface. Compared with the case of irradiating the part 8B, the optical loss is reduced.

  The features of the second optical member 6 in this embodiment will be sequentially described. First, a second optical member 6 having a shape different from that of the first optical member 5 corresponding to the front light emitting LED light source 3A is arranged corresponding to the side light emitting LED light source 3B. Further, the luminous intensity distribution of the outgoing light from the second optical member 6 is different from that of the outgoing light from the first optical member 5.

  The light emitted from the first optical member 5 corresponding to the front light emitting LED light source 3A has more light flux in the front direction Z than the light emitted from the second optical member 6 corresponding to the side light emitting LED light source 3B. The optical member is configured as described above. Further, the optical member is configured such that the light emitted from the second optical member 6 has more light flux in the side surface direction than the light emitted from the first optical member 5.

  This is because the front light emitting LED light source 3A having the maximum value of emitted light intensity in the front direction Z irradiates the front part 8a of the diffusion cover over a wide range, and the side light emitting LED light source 3B having the maximum value of emitted light intensity in the side surface direction is diffused cover. This is a configuration for realizing an optical system that irradiates the side surface portion 8b of the light source intensively, and by reducing the angle at which light from each LED light source is refracted, the number of times of reflection / scattering is reduced and the diffusion cover 8 is directly irradiated. By doing so, the optical loss is reduced.

The second optical member 6 has a light guide 6L. The most effective method of increasing the luminous flux incident on the side surface portion 8B of the diffusion cover is to bring the LED light source closer to the side surface portion 8B of the diffusion cover. In order to install a fixture (not shown) for fixing the diffusion cover 8 to the frame 11 between the end portion 2E of the substrate 2 and the side surface portion 8B of the diffusion cover, a certain space is required ( (See FIG. 2). Therefore, the LED light source has a limit in approaching it. In particular, when the end portion 2E of the substrate is brought close to the side surface portion 8B of the diffusion cover, the substrate 2 must be expanded.
Spreading the substrate 2 increases material costs and industrial waste. Further, a frame 11 as a heat dissipation path must be provided under the substrate 2. Therefore, when enlarging the substrate, it is necessary to expand the plane 11A of the frame 11 and bring the inclined portion 11B closer to the diffusion cover 8 along with it. In this case, it becomes particularly difficult to secure a space for installing the above-described fixture.

  Therefore, in this configuration having the light guide portion 6L, the light from the LED light source located at a position apart from the side surface portion 8B is guided to the vicinity of the side surface portion 8B by the light guide portion 6L and emitted toward the side surface portion 8. By emitting light from the surface, there is an effect of effectively increasing the light flux incident on the side surface portion 8B of the diffusion cover. Moreover, since there is almost no light loss even if it guides the light guide part 6L, there exists an effect which increases effectively the light beam which injects into the side part 8B of a diffusion cover, without accompanying a light loss.

  In this configuration, an optical member corresponding to a certain LED light source has a light guide portion, and the light guide portion 6L guides light to the outside in the side surface direction, and the light is emitted from the emission surface 6B to the outside X in the side surface direction. It is. Hereinafter, the outer side (direction) of the side surface direction may be referred to as a side surface outer side direction or a side surface direction outer side. All are the directions described as the lateral side direction X in the drawing.

  The exit surface 6B is a surface facing the entrance surface 6A and is substantially parallel to the entrance surface 6A. Since the surface is opposed to the incident surface 6A and is perpendicular to the direction in which light is guided, light is emitted from the emission surface 6B even without the light extraction means. For example, light is not emitted from a surface that is perpendicular to the incident surface 6A and that is parallel to the direction in which light is guided without the light extraction means.

  As shown in FIG. 6A, in the cross section parallel to the normal line of the substrate on which the LED light source 3B corresponding to the second optical member 6 is mounted, the emission surface shape of the second optical member 6 is a straight line. Thus, it is a straight line parallel to the incident surface 6A. In the case where the thickness of the exit surface is made equal to the thickness 6H of the light guide 6L, when the exit surface shape is a straight line, less light is reflected by the exit surface 6B and returns to the entrance surface 6A. This is the smallest when the shape of the exit surface is a straight line parallel to the entrance surface 6A. If the shape of the exit surface is a circle or an ellipse, more light is reflected from the exit surface and returns to the entrance surface 6A. The probability that the return light is emitted again from the emission surface and irradiates the side surface portion 8B is low. Therefore, in order to effectively increase the light flux to the side surface portion 8B of the diffusion cover, it is desirable that the shape of the emission surface is a straight line. In particular, in the case of a straight line parallel to the incident surface 6A, the return light is minimized, and it is more preferable to use a straight line parallel to the incident surface 6A.

  The exit surface 6 </ b> B of the second optical member 6 is located on the outer side in the lateral direction than the end 2 </ b> E of the substrate 2. By disposing the emission surface 6B in this manner, it is possible to effectively increase the luminous flux applied to the side surface portion 8B of the diffusion cover. This is because when the exit surface 6B is inside the end 2E of the substrate 2, approximately half of the light emitted from the exit surface 6B is reflected by the substrate 2. The light reflected by the substrate 2 propagates in the front direction Z and does not propagate in the direction opposite to the front direction Z. Further, since the reflected light propagates while diffusing, a lot of light propagates toward the front portion 8A of the diffusing cover. Therefore, in order to effectively increase the luminous flux to the side surface portion 8B of the diffusion cover, the outgoing light is reflected by the substrate 2 by disposing the outgoing surface 6B outside the end portion 2E of the substrate 2 in the side surface direction. Thus, it is effective to suppress the reduction of the light flux to the side surface portion 8B.

  For example, although the ray RAY4 shown in FIG. 6A is directed to the side surface portion 8B, if the exit surface 6B is on the substrate 2, the ray RAY4 is reflected by the substrate 2 and not the side surface portion 8B. There is a possibility of going to the front part 8A. When the surface of the substrate 2 is covered with a white optical system such as a white resist, the possibility of going to the front portion 8A is further increased.

  Therefore, by disposing the emission surface 6B on the outer side in the side surface direction from the end 2E of the substrate 2, the reflection on the substrate 2 can be drastically eliminated, so that the light flux to the side surface portion 8B of the diffusion cover is effectively reduced. The effect of increasing is obtained.

  When projecting the exit surface 6B to the outside of the substrate 2, there is a problem of securing a space for installing the fixture described above, but it is only necessary to arrange the exit surface 6B outside the plane 11A of the frame 11. There is no need to change the shape of the frame 11. In addition, there is no problem because the length of the light guide portion 6L may be adjusted according to the fixture.

Next, a method for effectively guiding the light incident from the incident surface 6A ′ will be described. The incident surface 6A faces the light emitting surface 3BE of the side-emitting LED light source 3B, and most of the emitted light enters the light from the incident surface 6A. On the other hand, the incident surface 6A ′ is a surface perpendicular to the light emitting surface 3BE, and is a surface on which outgoing light having a large angle from the normal direction of the light emitting surface 3BE is incident. Although the light beam incident from the incident surface 6A ′ is small as viewed from the whole, it may be about 20% of the total light beam.
Therefore, an optical means for guiding light in the lateral direction is provided.

  A prism surface 6C that forms an angle of approximately 45 degrees with the normal direction of the light emitting surface 3BE is present corresponding to the light emitting surface 3BE. The prism surface 6C has an optical shape that totally reflects the light incident from the incident surface 6A ′ in the direction of the exit surface 6B. The prism surface 6C is effective as long as it is inclined with respect to the normal direction of the light emitting surface 3BE, but the angle formed with the normal line is preferably 20 degrees or more and less than 70 degrees, and most preferably about 45 degrees. If the angle formed with the normal line is too small, more light is transmitted in the front direction Z without being reflected by the prism surface 6C. As the angle formed with the normal line increases, the prism surface 6C increases in the front direction, and thus the thickness 6H of the light guide 6L increases. Since it becomes heavier when it becomes extremely thick, the angle formed with the normal line is preferably less than about 70 degrees.

  Since most of the light incident from the incident surface 6A ′ is to be totally reflected in the direction of the exit surface 6B, the prism surface 6C is desired to overlap the incident surface 6A ′. When the distance between the light emitting surface 3BE and the incident surface 6A is G0, it is preferable that the projection of the prism surface 6C onto the normal line of the light emitting surface 3BE is larger than the distance G0.

  As described above in the description of the LED light source in FIG. 5, most of the light is emitted from the light emitting surface 3BE, but the frame 37 transmits part of the light, so that light leaks from the entire frame 37. In particular, light leaks from a portion where the frame 37 is thin. Light also leaks from the front surface of the side-emitting LED light source 3B. In order to reflect and guide this leaked light, when the width of the side surface direction of the side light emitting LED light source 3B is set to WLG, projection onto the normal line of the light emitting surface 3BE of the prism surface 6C is performed. It is preferable to be larger than (distance G0 + width WLG).

  Next, the composite optical member 7 configured by connecting the first optical member 5 and the second optical member 6 by the optical member connecting portion 4 will be described. Since the first optical member 5 and the second optical member 6 are connected by the optical member connecting portion 4, a plurality of effects can be obtained.

  FIG. 6B is a cross-sectional view taken along the line BB ′ of FIG. 1. The front light emitting LED light source 3A, the wide-angle lens that is the first optical member 5, the optical member connecting portion 4, and the second optical member 6 are mainly used. It is expressed in However, since there is no LED light source 3B corresponding to the second optical member 6, the second optical member 6 does not have the incident surfaces 6A and 6A 'but has the emission surface 6B. As examples of ray tracing, rays RAY5 and RAY6 are shown. A ray RAY6 ′ indicated by a dotted line from the middle is a ray representing a direction in which the ray RAY6 propagates when the optical member connecting portion 4 is not provided.

  In this configuration, as indicated by the light ray RAY5 and the light ray RAY6, the exit surface of the second optical member 6 enters the first optical member 5 from the front light emitting LED 3A and guides the optical member connecting portion 4. The propagating light also becomes the outgoing surface. If there is no optical member connecting portion 4, the light is emitted from the first optical member 5 located inside the substrate 2 and diffused like the ray RAY 6 ′. There is little light flux to irradiate.

  Therefore, when the first optical member 5 and the second optical member 6 are connected by the optical member connecting portion 4, a part of the light emitted from the LED light source 3 </ b> A corresponding to the first optical member 5 is second. It is possible to propagate to the exit surface 6B of the optical member 6 and directly irradiate the side surface portion 8B, and there is an effect that the indirect light of the illumination device 1 is increased. Moreover, since it propagates by light guide, the effect of suppressing light loss and directly irradiating the side surface portion 8B is also achieved.

The height 4H of the optical member connecting portion is smaller than the height 5H of the first optical member. This has the effect of reducing the weight of the optical member connecting portion 4, but has other optical meanings. In order for light to be guided through the optical member connecting portion 4, the light propagating to the reflecting surface 4 </ b> C of the optical member connecting portion must satisfy the total reflection condition derived from Snell's law. When the refractive index of the optical member connecting portion 4 is _nm and the angle from the normal line of the reflecting surface 4C is the incident angle, the incident angle is sin ⁻¹ (1 / n _m ) in order to guide light. The angle must be larger than the critical angle obtained in.

  For example, a resin such as polycarbonate or acrylic has a critical angle of about 40 degrees, and therefore the method of the substrate 2 on which the LED light source 3A is mounted among the light emitted from the LED light source 3A corresponding to the first optical member 5. When the angle from the line is the light source light distribution angle, at least light with a light source light distribution angle of 0 to 40 degrees is not guided and should be emitted from the first optical member 5. Desirably, light having a light source distribution angle of 0 to 60 degrees is emitted from the first optical member 5 to irradiate the front surface portion 8A of the diffusion cover, and guides the light beam having an angle larger than that to guide the side surface portion 8B. It is desirable to irradiate. In order to prevent a light beam having a light source distribution angle smaller than a certain angle from entering the optical member connecting portion 4, the height 4H of the optical member connecting portion needs to be smaller than the height 5H of the first optical member. .

  Making the height 4H of the optical member connection portion smaller than the height 5H of the first optical member has an effect of controlling the angle of the light beam incident on the optical member connection portion 4, and the optical member connection portion. Since only the light that guides light 4 can be incident, there is an effect of reducing the light lost as stray light after entering the optical member connecting portion 4.

  Next, since the composite optical member 7 covers the electrode 40, when the diffusion cover 8 is removed, an effect of a protective cover that prevents a person from touching the electrode 40 and receiving an electric shock is also obtained. explain. As shown in FIG. 6 (a), the composite optical member 7 is arranged so that the light from the first optical member 5 is guided from the first optical member 5 in order to guide the light to the emission surface 6B of the second optical member. The composite optical member 7 covers up to the emission surface 6B. At that time, the electrode 40 is also covered so as not to be touched by a person.

  When the composite optical member 7 does not cover the electrode 40, another member is required to cover the electrode 40, and the other member becomes a shadow of the composite optical member 7 and optical interference occurs. Since a problem occurs, covering the electrode 40 with the composite optical member 7 has an effect of not causing the problem.

  7A and 7B are diagrams for explaining the electrode 40, the electrode 40 'and the composite optical member 7 in detail. FIG. 7A is a front view, and FIG. 7B is a cross-sectional view taken along line G- in FIG. It is G 'sectional drawing. The GG ′ cross section is a cross section along the locus in the composite optical member 7 of the ray tracing example RAY7. In FIG. 7A, the shape of the electrode 40 and the electrode 40 'is determined corresponding to the mounting terminal of the LED light source, and is also arranged outside the LED light source. The composite optical member 7 is disposed so as to cover the electrode 40. Further, since the rear surface 7R of the composite optical member is also present on the surface facing the electrode 40, the light guided from the LED light source 3A is not reflected or lost by the electrode 40 as shown in FIG. In addition, it is possible to pass through the position 7 </ b> R facing the electrode 40. Covering the electrode 40 with the composite optical member 7 produces an effect that not only the protective cover for preventing electric shock but also the light reflected and scattered by the electrode 40 can be reduced.

  Furthermore, when the number of LED light sources included in the illumination device 1 exceeds several tens, it is time consuming to attach and align the optical member, which is not desirable from the viewpoint of power saving and work cost. Incidentally, in the case of a room application wider than a living room with a lighting device attached to the ceiling, usually several tens or more LED light sources are required.

  However, in the case of a composite optical member in which a plurality of optical members are gathered, there is an effect that the number of mounting operations is reduced. Further, when all the optical members are made by batch molding as in the present embodiment, the time required for attachment is remarkably improved. Further, when there are a plurality of types of optical members, when a batch-molded composite optical member is attached, there is an effect that there is no mistake in attaching the optical member to the corresponding LED light source.

  Next, the arrangement of the LED light sources in the optical system including the front light emitting LED light source 3A and the side light emitting LED light source 3B will be described. As described above, the side-emitting LED light source 3B is preferably disposed on the outermost side in order to directly irradiate the side surface portion 8B. In another expression, it is preferably present in the vicinity of the end 2E of the substrate 2. More directly, it is preferable that there is no obstacle between the exit surface 6B and the side surface portion 8B, and the emitted light can reach the side surface portion 8B without being reflected or scattered during propagation. The arrangement of the front light emitting LED light source 3A will be described with reference to FIG.

A distance D3L described in FIG. 1 is a distance from the center C to the side-emitting LED light source 3B.
The distance D2L is a distance from the center C of the closest front light emitting LED light source 3A closest to the side light emitting LED light source 3B. The distance D1L is a distance from the center C of the front light emitting LED light source 3A inside the nearest front light emitting LED light source 3A. However, any LED light source defines a distance between LED light sources having substantially the same color.

As described above, it is an important issue to reduce the glare by making the illuminance of the diffusion cover 8 uniform, making the light emitting surface clean and uniform. Since the emitted light flux is small in the front direction of the side light emitting LED light source 3B, there arises a problem that the illuminance of the diffusion cover front surface portion 8B in the front direction of the side light emitting LED light source 3B becomes low and dark. Therefore, in order to improve the illuminance uniformity, the front light emitting LED light source 3A is disposed near the side light emitting LED light source 3B. Therefore, the distance between the side-emitting LED light source 3B and the closest front-emitting LED light source 3A closest thereto is smaller than the distance between the closest front-emitting LED light source 3A and the LED light source 3A located inside thereof.
However, when there are a plurality of LED light sources of different colors, the same color is used for uniformization. Therefore, the distance is defined between LED light sources of the same color. Further, such an arrangement satisfies (D3L-D2L) <(D2L-D1L).

  In addition, as an example of a wide-angle lens disposed corresponding to the front-emitting LED light source 3A, an isotropic lens has been described in the mounting surface of the LED light source 3A. The lens that is anisotropic in the mounting surface will be described. For example, in the case of a circular illumination device, when a polar coordinate system with the center C as the origin is considered, the LED light sources are arranged more densely in the azimuth direction than the radial direction (the interval between the LED light sources of substantially the same color is small). Therefore, when viewed from the front, it is conceivable to make the lens width different in the radial direction and the azimuth direction to change the emission distribution of the emitted light from the lens to make it uniform. In that case, generally, the larger the lens width, the more light can be emitted at a wider angle, so the lens width in the radial direction is larger than the lens width in the azimuth direction.

  When generalized, the lens width in the direction where the LED light sources are dense (the interval between the LED light sources of substantially the same color is small) is larger than the lens width in the direction where the LED light sources are coarse (the interval between the LED light sources of approximately the same color is large). .

  FIG. 16 shows various examples of the first optical member 5 and the second optical member 6.

  In FIG. 16A, the first optical member 5 has an incident surface 5A and an exit surface 5B having substantially similar cross-sectional shapes, and the second optical member 6 has a light guide portion. When the LED light source is placed at the center of the member, the first optical member 5 has a shape that emits light emitted from the LED light source with almost no refraction (see ray tracing example RAY21). This shape is effective when the light distribution of the emitted light from the LED light source is desired to be the emitted light from the optical member as it is. When the member is a wide-angle lens, a part of the light is reflected by the Fresnel reflection on the emission surface 5B and may be absorbed by the substrate or the like. On the other hand, when the cross-sectional shapes of the entrance surface 5A and the exit surface 5B are substantially similar, the Fresnel reflection at the exit surface 5B is minimized. Therefore, the light loss due to the influence of the optical member is the smallest. In addition, by placing the optical member of this shape near the side-emitting LED light source, the luminous intensity in the normal direction of the light-emitting surface is greater than when placing a wide-angle lens, improving the front-side uniformity of the side-emitting LED light source Can be made.

  FIG. 16B is a front view of another example, and FIG. 16C is a cross-sectional view taken along the line AA ′ in FIG. In this example, the exit surface 6B is outside the end 2E of the substrate 2, but there is a gap 6AR in the cross section including the LED light source 3B and the exit surface 6B. As shown in the ray tracing example RAY22, the light emitted from the LED light source 3B is incident on the incident surface 6A, is emitted from the emission surface 6B0 to the gap 6AR, propagates in the air, and is transmitted to the second optical member 6. Is incident on the incident surface 6B1 of the outermost portion of the light, and exits from the exit surface 6B of the portion toward the side surface portion 8B. In this example, although there is no light guide part, light propagates in the air and light is emitted from the emission surface 6B outside the end 2E of the substrate 2.

  The part having the exit surface 6B and the part having the entrance surface 6A are fixed as appropriate. In this example, they are connected by a rod-shaped portion 6F.

  Moreover, it is good also as a structure into which light injects directly into the entrance plane 6B1 of the outermost part of the 2nd optical member 6 from a side light emission LED light source. In that case, the incident surface 6B1 serves as the incident surface 6A.

  Further, the cross-sectional shape of the exit surface 6B0 to the gap 6AR is not limited to a straight line, but may be a lens shape such as a curve. Further, the cross-sectional shapes of the incident surface 6B1 and the exit surface 6B may each be a straight line or a curved lens shape. It is only necessary to irradiate the side surface portion 8B of the diffusion cover with a combination of both.

  In this configuration, the emission surface 6B is disposed outside the end portion 2E of the substrate 2 and has a shape for efficiently irradiating the side surface portion 8B. The emission surface 6B is generally arranged symmetrically with respect to the LED light source 3B. The size 6H of the cross section of the exit surface 6B is larger than the cross section of the exit surface 6B0 to the gap 6AR. These features are obtained because the optical surface such as the output surface 6B does not interfere with the substrate 2 by disposing the output surface 6B outside the end 2E of the substrate 2. Therefore, by arranging the emission surface 6B outside the end portion 2E of the substrate 2, there is an effect that the side surface portion 8B is efficiently irradiated.

  FIG. 8 is a diagram for explaining the configuration of the illumination device according to the second embodiment of the present invention. Description of the same parts as those in the first embodiment is omitted. In FIG. 8, the part different from the first embodiment is the shape of the emission surface 6 </ b> B of the second optical member 6. The shape of the emission surface of the second optical member 6 having the light guide portion is not a straight line but a curve. The exit surface shape of the second optical member 6 has an arc shape. The cross-sectional shape of the emission surface 6B of the second optical member 6 is a shape for solving the problem described below.

  A problem to be solved in the present embodiment will be described with reference to FIGS. FIGS. 9A to 9C are systems including the LED light source 3B, the light guide 6L, and the screen SCN, and are optical systems for explaining the phenomenon.

  FIG. 9 (a) shows a ray of light emitted from the LED light source 3B that is not reflected by the upper surface 6LA and the lower surface 6LB of the light guide 6L but directly propagates from the incident surface 6A to the emission surface 6B and is emitted into the air. It is the figure which represented RAY8 and the irradiance distribution I0 which the said light ray reflects on the screen SCN typically. Since this example is an example in which the center axis 6LC of the LED light source 3B and the light guide 6L coincides, there is a peak of the irradiance distribution I0 on the center axis. For the sake of explanation, the x-coordinate axis XCD on the screen having the same origin as the central axis 6LC is shown in the figure.

  FIG. 9B shows a ray RAY9 of light emitted from the LED light source 3B, which is reflected only once by the upper surface 6LA after being incident from the incident surface 6A, propagates to the emission surface 6B, and is emitted into the air. It is the figure which represented typically the irradiance distribution I1 which a light ray reflects on the screen SCN. The irradiance distribution I1 has a peak at a position shifted from the central axis 6LC, and the peak deviates in the x coordinate axis XCD direction.

  FIG. 9C is an example in which the light rays in FIGS. 9A and 9B are superimposed. The superposition of the irradiance distributions I0 and I1 is the irradiance distribution of the screen. Since the irradiance distribution having a peak is overlaid with a certain interval, light and dark unevenness occurs in a stripe pattern on the screen. In FIG. 9C, only two light guide paths are considered, but in actuality, the results of many paths are superimposed, and light and dark unevenness occurs in a wide range. When the light guide path is classified according to the number of reflections from the incident surface to the output surface, there is a peak for each light guide path, and all of these overlaps are unevenly repeated on the screen in light and dark. It is to generate.

FIG. 9D shows the result calculated by simulation. The length of the light guide at the time of calculation is 50 mm, a 200 mm square screen is placed 150 mm away from the exit surface of the light guide, the thickness of the light guide plate in the direction parallel to the x axis is 3 mm, and the width of the LED light source is The result is 1 mm. The vertical axis represents irradiance (W / mm ² ), and the horizontal axis represents the x coordinate on the screen. The irradiance is maximized around 0 mm on the central axis 6LC, and becomes darker while repeating the brightness as the position increases.

  This phenomenon is a phenomenon that occurs when a member having a light guide portion is used. The light guide portion is a transparent resin, glass, ceramic, or the like of about 5 mm to several hundred mm, and is a member that propagates light over the distance. Some lighting devices have a light guide section longer than 1 m. In the case of the lighting device, the screen corresponds to the diffusion cover 8, and light and darkness is generated on the diffusion cover 8. The unevenness of brightness and darkness generated in the illumination device significantly deteriorates the uniformity of the light emitting surface, lowers the design value of the diffusion cover 8, and may result in bright bright lines. In this embodiment, it is an object to reduce unevenness due to this phenomenon and obtain uniformity of a light emitting surface.

This phenomenon will be described in more detail with reference to FIG. This phenomenon strongly depends on the positional relationship between the light emitting surface 3BE of the LED light source and the central axis 6LC of the light guide. FIG. 10A is a schematic diagram of the positional relationship between the LED light source and the incident surface 6A corresponding to the case of FIG. FIG. 10B is a schematic diagram of the positional relationship when the center of the light emitting surface 3BE of the LED light source and the center axis 6LC of the light guide section are shifted by −0.5 mm in the x coordinate axis XCD direction. FIG. 10C shows the case where the center of the light emitting surface 3BE of the LED light source and the center axis 6LC of the light guide portion coincide with each other, and the thickness of the light guide plate and the light emission of the LED light source in the direction parallel to the x axis. The case where the width | variety of surface 3BE is equal is shown. FIG. 10D shows the calculation result of the position distribution of the irradiance (W / mm ² ) in the case of FIGS. 10A to 10C. Result of calculation when the length of the light guide is 50 mm, a 200 mm square screen is placed 150 mm away from the light exit surface of the light guide, the thickness of the light guide plate is 3 mm, and the width of the LED light source is 1 mm It is. The vertical axis represents irradiance (W / mm ² ), and the horizontal axis represents the x coordinate on the screen.

  The solid line 10 (a) is the result in the case of FIG. 10 (a) and is the same as the result shown in FIG. 9 (d). Shown for comparison.

  The broken line 10 (b) is the result in the case of FIG. It can be seen that the brightness unevenness is remarkably increased. That is, it can be seen that the unevenness increases when the center of the light emitting surface 3BE of the LED light source and the center of the light guide portion are shifted. Unevenness occurs due to the peak of each light guide path classified by the number of reflections from the incident surface to the output surface. When the center of the light emitting surface 3BE of the LED light source and the center of the light guide are equal, the peaks exist at a certain interval, and exist symmetrically with respect to the central axis in the thickness direction (x coordinate axis XCD direction) of the light guide. To do. On the other hand, when the center of the light emitting surface 3BE of the LED light source is different from the center of the light guide part, the peak position exists asymmetrically with respect to the central axis in the thickness direction of the light guide part (x coordinate axis XCD direction). To do. Therefore, when the centers are different, there are a light guide path whose peak approaches and a light guide path whose peak moves away on the screen. The place where the peak approaches is brighter and the place where the peak goes away becomes darker. For example, peak 1 corresponding to the light guide path 1 and peak 2 corresponding to the light guide path 2 may approach, and peak 1 and peak 3 corresponding to the light guide path 3 may move away. In this case, peak 1 and peak 2 The overlapped portion becomes brighter, and between peak 1 and peak 3 becomes darker. Therefore, when the centers are different, extremely large unevenness occurs as shown by the broken line 10 (b).

  The dotted line 10 (c) is the result in the case of FIG. 10 (c), and it can be seen that unevenness is suppressed when the thickness of the light guide plate and the width of the light emitting surface 3BE of the LED light source are equal. This is because light of all angles enters the entire incident surface 6A. In other words, when the width of the light emitting surface of the LED light source facing the incident surface 6A is equal to or larger than that of the incident surface 6A, unevenness is suppressed.

The method for reducing the unevenness is that the shape of the light exit surface of the second optical member 6 having the light guide portion in the cross section parallel to the normal line of the substrate on which the LED light source corresponding to the second optical member 6 is mounted. By making the shape not a straight line, and by making it a curve, a significant improvement can be obtained.
Furthermore, by making the exit surface shape arcuate, it is possible not only to eliminate unevenness but also to collect the angular distribution of the exit light.

  However, when the shape of the exit surface of the second optical member 6 having the light guide portion is a straight line, there is an advantage that the light guided is less reflected by the exit surface 6B and returned to the entrance surface 6A. The return light returns to the incident surface 6A and is emitted from the incident surface 6A in the direction opposite to the emission surface 6B. Therefore, the indirect light cannot be increased efficiently without reaching the side surface portion 8B. The unevenness described above is reduced when the length of the light guide portion, which is the distance between the entrance surface 6A and the exit surface 6B, is short (approximately less than 15 mm), and when the distance between the exit surface 6B and the diffusion cover 8 is small. Since the peak position is not resolved on the diffusion cover 8, it is difficult to recognize it as unevenness. In such a case, indirect light can be efficiently increased by making the shape of the exit surface 6B a straight line in consideration of the merit that there is little return light.

  Here, the return light will be described with reference to FIGS. FIG. 11A is a schematic view when the cross-sectional shape of the emission surface 6B is a semicircle, and the diameter 6BD of the semicircle is 3 mm, which is the same as the thickness 6LH of the light guide. FIG. 11B shows a case where the cross-sectional shape of the exit surface 6B is an arc having a central angle larger than that of a semicircle, and the diameter 6BD of the arc is larger than the thickness 6LH of the light guide. . In each figure, two ray tracing examples RAY10 and RAY11 are described.

The angles formed by the light rays RAY10 and 11 before being reflected by the light guide 6L and the central axis 6LC are equal. The ray RAY10 is a ray that is emitted into the air without being totally reflected from the emission surface 6B when the cross-sectional shape of the emission surface 6B is a straight line. However, when the cross-sectional shape of the exit surface 6B is a curve such as a circle or an ellipse (spherical or aspherical curve), light that repeats total reflection and returns is generated.
This is the cause of the return light described above.

  One method for reducing the return light is to make the cross-sectional shape of the exit surface 6B larger than the thickness 6LH of the light guide. An example of this is shown by RAY 11 shown in FIG. This effect has been confirmed by a simulation described later.

Here, the reduction in brightness unevenness when the cross-sectional shape of the emission surface 6B is curved will be described with reference to FIG. FIG. 11C shows the positional relationship between the center of the light emitting surface 3BE of the LED light source and the central axis 6LC of the light guide unit in the optical system described in FIG. This is a calculation result in a configuration in which the center is shifted by −0.5 mm in the x coordinate axis XCD direction (positional relationship in FIG. 10B). The screen of this optical system is a 200 mm square screen, and is disposed about 150 mm away from the light exit surface of the light guide. The thickness of the light guide plate is 3 mm, and the width of the LED light source is 1 mm. The vertical axis represents irradiance (W / mm ² ), and the horizontal axis represents the x coordinate on the screen.

  A solid line 9 (a) I0 shown in FIG. 11C is reflected by the upper surface 6LA and the lower surface 6LB of the light guide portion 6L in the light emitted from the LED light source 3B when the cross-sectional shape of the emission surface 6B is a straight line. Without showing, an irradiance distribution in which a light beam directly propagating from the incident surface 6A to the exit surface 6B and exiting into the air is displayed on the screen.

  As shown in FIG. 11 (a), the broken line 11 (a) I0 has a curved semicircular cross section of the exit surface 6B, and the semicircular diameter 6BD is the same as the light guide thickness 6LH. The irradiance distribution in the case of 3 mm is shown.

  When the cross-sectional shape of the exit surface 6B is a straight line, it has a sharp peak near the center as shown by the solid line 9 (a) I0, but when the cross-sectional shape of the exit surface 6B is a semicircle, the broken line 11 (a) I0 As shown in Fig. 1, it has a gentle peak near the center.

When the light guide paths are classified by the number of reflections from the incident surface to the output surface, the actual irradiance distribution is obtained by superimposing the contributions of the respective light guide paths. When the cross-sectional shape of the exit surface 6B is a straight line, unevenness in brightness and darkness occurred because the irradiance distribution having sharp peaks was overlapped.
However, when the distributions having gentle peaks are overlapped as indicated by the broken line 11 (a) I0, unevenness in brightness does not occur. Therefore, unevenness can be reduced by making the cross-sectional shape of the exit surface 6B different from a straight line, making it a curved line and an arc.

  Next, a simulation result regarding the effect of reducing unevenness by the present configuration will be described. FIG. 11 (d) shows the result. The simulation optical system is an optical system that performs the calculations of FIGS. 9D and 10D. This is an optical system in which a 200 mm square screen is arranged at a distance of about 150 mm from the exit surface of the light guide unit, the thickness of the light guide plate is 3 mm, and the width of the LED light source is 1 mm. The positional relationship between the center of the light emitting surface 3BE of the LED light source and the central axis 6LC of the light guide unit is a case where the center of the light emitting surface 3BE is shifted by −0.5 mm in the x coordinate axis XCD direction with respect to the central axis 6LC (FIG. 10 (b)).

In FIG. 11D, the vertical axis represents the irradiance (W / mm ² ), the horizontal axis represents the x coordinate on the screen, and the position distribution of the irradiance (W / mm ² ) is shown. A broken line 10 (b) is a result for the case of FIG. 10 (b), and the cross-sectional shape of the emission surface is a straight line and is for comparison.

  The solid line 11 (a) is the case of FIG. 11 (a), the dotted line 11 (b) 4 is the case where the diameter 6BD of the arc is 4 mm in FIG. 11 (b), and the dotted line 11 (b) 6 is the case of FIG. In (b), the arc diameter 6BD is 6 mm.

  As is clear from FIG. 11D, it can be seen that unevenness is remarkably improved by making the cross-sectional shape of the exit surface 6B a curve.

  Further, the amount of light reaching the screen is approximately 0.8 in the case of FIG. 11A when the cross-sectional shape of the exit surface 6B is a straight line, and the diameter 6BD in FIG. When the diameter is 4 mm, it is approximately 1.0, and when the diameter 6BD is 6 mm in FIG. 11B, it is approximately 1.4.

  If the cross-sectional shape of the emission surface 6B is as shown in FIG. 11A from a straight line, the amount of light reaching the screen by the return light is reduced. On the other hand, when the diameter 6BD of the cross-sectional shape of the exit surface 6B is 4 mm, the return light is improved, and the amount of light reaching the screen is larger than that in FIG. In other words, the effect of reducing the return light is obtained by making the cross-sectional shape of the exit surface larger than the thickness of the light guide.

  Further, when the diameter 6BD of the cross-sectional shape of the exit surface 6B is changed from 4 mm to 6 mm, the amount of light reaching the screen increases and the irradiance of a specific area of the screen increases as shown in FIG. It has become. This indicates that the emitted light is condensed. By condensing the emitted light, the side surface portion 8B of the diffusion cover can be more effectively irradiated, and the indirect light can be increased. A similar phenomenon occurs when the diameter 6BD of the cross-sectional shape of the exit surface 6B is changed from 3 mm to 4 mm, but it appears prominently when the diameter 6BD is changed from 4 mm to 6 mm.

  Therefore, the unevenness of brightness and darkness is reduced by making the cross-sectional shape of the exit surface 6B a curve, and the return light generated by making the curve by making the cross-sectional shape of the exit surface 6B larger than the thickness of the light guide unit. And condensing outgoing light, and effectively illuminating the side surface 8B of the diffusion cover to increase indirect light.

  FIG. 8 shows an example in which the second optical member 6 having the cross-sectional shape of FIG.

  In FIG. 17, it showed regarding various shapes of the cross-sectional shape of a light guide part and the output surface 6B.

  FIG. 17A is an example in which the cross-sectional shape of the exit surface is configured by a straight portion 6B2 and a curved portion 6B1. DL represents the distance from the entrance surface 6A to the tip of the exit surface. The light guide part is between the incident surface and the straight part 6B2.

FIG. 17B is an example in which the light guide has an inclined surface. This example is a configuration in which the thickness of the light guide portion decreases as it approaches the exit surface 6B. In this case, a part of the light may be emitted from the upper surface 6L1 and the lower surface 6L2 because the total reflection condition is broken on the upper surface 6L1 and the lower surface 6L2 of the light guide unit.
This is an effective configuration when it is desired to increase the number of emission surfaces in addition to 6B. Moreover, since a thin site | part is made, weight reduction can also be performed.

  FIG. 17C is an example in which the light guide has an inclined surface. In this example, the thickness of the light guide portion increases as it approaches the light exit surface 6B. In the case of this configuration, as the light beam is guided through the light guide portion 6L, the direction (angle) in which the light beam propagates is reflected from the upper surface 6L1 and the lower surface 6L2 in the direction from the incident surface 6A to the output surface 6B (side surface direction). Therefore, the light beam collimates as it propagates.

  FIG. 17D shows an example in which the cross-sectional shape of the emission surface is a polygonal line. This configuration also has an effect of suppressing light and dark unevenness.

  FIG. 17E is an example in which the exit surface has a plurality of optical shapes, and the exit surface 6B is configured by the shape of three cylindrical lenses 6B3. For example, the exit surface 6B is a fly-eye lens or the like. By using a plurality of optical shapes, it is possible to control the detailed emission angle distribution according to each position on the emission surface. This configuration also has an effect of suppressing light and dark unevenness.

FIG. 12 is a diagram for explaining a configuration of an illumination apparatus according to the third embodiment of the present invention.
Description of the same parts as those in the first embodiment is omitted. The difference from the first embodiment is that the light extraction means 4E is provided in the optical member connecting portion 4 connecting the first optical member 5 and the second optical member 6, and the second The light extraction means 6LE is provided on the lower surface 6LB of the light guide portion 6L of the optical member, light is emitted from the upper surface 6LA of the light guide portion 6L, and the upper surface 6LA of the light guide portion 6L functions as a second emission surface. It is a point.

  This is a configuration for improving the illuminance uniformity of the diffusion cover 8 by extracting a part of the light guide light also in the front direction Z so that sufficient light can reach the cover member far from the LED light source. It is.

  The light extraction means 4E and the light extraction means 6LE may be on the front surface of each member, and can extract light in the front direction Z even if it is on a surface opposite to the surface.

  When the second optical member 6 has a light guide and no light extraction means 6LE, when the light emitted from the LED light source 3B is incident on the second optical member 6, the light other than the return light is emitted from the emission surface 6B. Therefore, no light is emitted in the front direction of the light guide 6L. Therefore, the front part 8A of the diffusion cover in the front direction of the light guide part 6L may become dark. On the other hand, the side surface portion 8B of the diffusion cover is brightened by the light from the exit surface 6B. In order to reduce this uneven brightness, the light extraction means 6LE is arranged outside the LED light source 3B of the second optical member 6, and the exit surfaces are two surfaces 6LA and 6B. For example, the unevenness is reduced by light from the exit surface 6LA as shown by the ray RAY12. As the shape of the light guide portion of the second optical member 6, in addition to the case where the exit surface is two surfaces 6LA and 6B as shown in FIG. 12, it may be a wedge shape with two or more exit surfaces. Not exclusively.

  If the light extraction means 4E of the optical member connecting portion 4 is present between the LED light sources 3, the effect of equalization is achieved. For example, as shown in the ray RAY13, a great effect can be obtained particularly when it is in the vicinity of the side-emitting LED light source or between the side-emitting LED light source and the front-emitting LED light source.

  This is because the side-emitting LED light source does not emit light in the normal direction of the mounting surface, and the diffusion cover located in the normal direction may become dark. If there is the light extraction means 4E in the vicinity of the side-emitting LED light source, light in the direction of the diffusion cover is generated, so that unevenness can be effectively suppressed.

  Various methods are conceivable for the light extraction means 4E and the light extraction means 6LE of the optical member connecting portion 4. For example, it is possible to give irregularities having a prism-shaped cross section as shown in the figure, to give irregularities of spherical or aspherical microlenses, and to print white scattering dots.

FIG. 13 is a diagram for explaining a configuration of an illumination apparatus according to the fourth embodiment of the present invention.
The description of the same portions as the first embodiment or the portions having the same functions is omitted. The difference from the first embodiment is that the normal line of the substrate 2 and the front direction Z are not parallel, and the substrate 2 is inclined outward in the lateral direction. In this example, a front light emitting LED light source is used instead of a side light emitting LED light source as the LED light source located on the outermost side in the side surface direction. Moreover, in order to irradiate efficiently the side part 8B of the diffusion cover 8, the 2nd optical member 6 is installed corresponding to the said LED light source 3B. The second optical member 6 does not have a light guide and is an optical member having a shape different from that of the first optical member 5.

  By tilting the substrate 2, the projection in the side surface direction of the light emitting surface of the front light emitting LED light source is increased. Therefore, all the LED light sources on the substrate 2 contribute to the irradiation of the side surface portion 8B. A ray RAY14 indicates light traveling from the first optical member 5 toward the side surface portion 8B.

  Here, the LED light source 3A corresponding to the first optical member 5 and the LED light source 3B corresponding to the second optical member 6 may be the same LED light source or different LED light sources.

  Furthermore, the second optical member 6 is a member designed so that the light distribution (or light flux) to the side surface portion 8B is larger than that of the first optical member 5, and the diffusion cover is more efficiently provided by this member. The light is emitted to the side surface portion 8B of 8 (see the ray RAY15).

  In this example, the second optical member 6 has an asymmetric shape in the in-plane direction perpendicular to the normal direction of the substrate 2. The cross-sectional shape of the cross section including the normal line of the substrate 2 is different between the surface that emits light outward in the lateral direction and the surface that emits light inward in the lateral direction. This is because the surface emitting light outward in the lateral direction emits a lot of light to the side surface portion 8B, but the surface emitting light inward in the lateral direction makes the front portion 8A uniform with the first optical member 5. It is.

  The role of the optical member connecting portion 4 is the same as that described in the first embodiment. Since the first optical member 5 and the second optical member 6 are connected by the optical member connecting portion 4, part of the emitted light of the LED light source 3 </ b> A corresponding to the first optical member 5 is converted to the second optical member. Propagation to the exit surface 6B of the member 6 makes it possible to directly irradiate the side surface portion 8B, and the indirect light of the lighting device 1 is increased. At this time, the position closest to the side surface portion 8B at the end portion of the composite optical member 7 is not always the exit surface 6B of the second optical member 6, but the end portion on the outer side in the side surface direction of the optical member connecting portion 4. It may become. Therefore, the fact that the first optical member 5 and the second optical member 6 are connected by the optical member connecting portion 4 is not only from the emission surface 6B, but also from the end of the optical member connecting portion 4 on the outer side in the side surface direction. The light is emitted and the indirect light of the lighting device 1 is increased.

  FIG. 14 is a front view for explaining the configuration of the illumination device according to the fifth embodiment of the present invention, as viewed from the normal direction of the substrate 2 on which the LED light sources 3A and 3B are mounted. The description of the same portions as the first embodiment or the portions having the same functions is omitted. The definitions of the front direction Z and the side direction are as described in the first embodiment.

  FIG. 15A is a cross-sectional view taken along the line AA ′ of FIG. The cross section is a plane parallel to the normal line of the substrate on which the LED light sources 3A and 3B are mounted. FIG. 15B is a cross-sectional view taken along the line BB ′ shown in FIG.

  The difference from the first embodiment is the outer shape. The outer shape of the first embodiment viewed from the front is a circle, and is optically isotropic in the side surface direction. On the other hand, the external shape seen from the front of this example is a rectangle. The concept of the present invention described in the first to fourth embodiments can be appropriately designed and optimized for this embodiment. The present invention can increase the indirect light without prescribing the outer shape, and can obtain the effect of making the illuminance of the diffusion cover 8 uniform and uniform. As an example, a case will be described in the present embodiment where the outer shape viewed from the front is a rectangle.

  Most of the LED light sources 3A are arranged on the inner side (side closer to the center C) than the LED light sources 3B. A part exists near the LED light source 3 </ b> B and near the end 2 </ b> E of the substrate 2. The substrate 2 is scattered throughout the substrate 2 and is disposed so as to surround the center C. The LED light source 3A is a front-emitting LED light source. The first optical member 5 corresponding to the light source is a wide-angle lens and improves the uniformity of the diffusion cover 8.

Most of the LED light sources 3B exist near the end 2E of the substrate 2 and are arranged outside along the end 2E. The LED light source 3B is a side-emitting LED light source. The second optical member 6 corresponding to the light source has a light guide. The light emitting surface 3BE is arranged to emit light toward the outside in the side surface direction. The incident surface 6A of the second optical member 6 is disposed to face the light emitting surface 3BE.
The light beam incident from the incident surface 6A propagates through the light guide 6L and exits from the exit surface 6B, as indicated by the light beam RAY2 ′, the light beam RAY3 ′, and the light beam RAY4 ′ in FIG. Since the LED light source 3B exists in the vicinity of the end 2E of the substrate 2, there is no obstacle such as another LED light source between the incident surface 6A and the exit surface 6B, and the incident light is not reflected during the light guide. Can be emitted. The second optical member 6 described in this example basically has all the features described in the first embodiment and the effects thereof, and has the effect of increasing indirect light.

  In the second optical member 6 in this example, the portion 6BR corresponding to the corner of the rectangle is not a corner but a rounded curve in front view. If the exit surface 6B has a corner, a bright line may be generated in the diffusion cover 8 correspondingly. Therefore, when the approximate shape of the outer shape is a polygon or the like, unevenness due to the corners can be suppressed by rounding the shape of the emission surface B corresponding to the corners.

  Next, the composite optical member 7 configured by connecting the first optical member 5 and the second optical member 6 by the optical member connecting portion 4 will be described. By connecting the first optical member 5 and the second optical member 6 with the optical member connecting portion 4, the plurality of effects described in the first embodiment can be obtained as in the first embodiment.

  In FIG. 15B, the front-emitting LED light source 3A, the wide-angle lens that is the first optical member 5, the optical member connecting portion 4, and the second optical member 6 are mainly represented. However, since the LED light source 3B corresponding to the second optical member 6 is not provided, the second optical member 6 does not have the incident surface 6A and the incident surface 6A ′, but has the exit surface 6B. In addition, as an example of ray tracing, a ray RAY5 ′ and a ray RAY6 ″ are shown.

  As indicated by the light beam, the first optical member 5 and the second optical member 6 are connected by the optical member connecting portion 4 so that the light emitted from the LED light source 3A corresponding to the first optical member 5 is obtained. Is partially propagated to the exit surface 6B of the second optical member 6 so that the side surface portion 8B can be directly irradiated, and the indirect light of the illumination device 1 is increased.

  Further, since the composite optical member 7 covers the electrode 40, the effect of a protective cover that prevents a person from touching the electrode 40 and receiving an electric shock when the diffusion cover 8 is removed is also obtained.

  Next, the arrangement of the LED light sources in the optical system including the front light emitting LED light source 3A and the side light emitting LED light source 3B will be described. As described above, the side-emitting LED light source 3B is preferably disposed on the outermost side in order to directly irradiate the side surface portion 8B. As described in the first embodiment, the front-side direction Z of the side-emitting LED light source 3B has a small amount of luminous flux, so that the illuminance of the diffusion cover front part 8B in the front direction of the side-emitting LED light source 3B is reduced and darkened. Challenges may occur. Therefore, in order to improve the illuminance uniformity, the front light emitting LED light source 3A is disposed near the side light emitting LED light source 3B.

  Therefore, the distance between the side-emitting LED light source 3B and the front-emitting LED light source 3A is preferably shorter than the distance between the front-emitting LED light sources 3A. Such an example will be described with reference to FIG. The distances Dt1, Dt2, Dt3, and Dt4 represent the distances between the front light emitting LED light sources 3A. On the other hand, distances Ds1 and Ds2 represent distances between the side-emitting LED light source 3B and the front-emitting LED light source 3A. Basically, it is preferable that the distances Dt1, Dt2, Dt3, Dt4> distances Ds1, Ds2. However, the inequality sign may not hold for all distances. For example, when distance Dt4> distance Ds2, there may be a case where distance Ds2> distance Dt3.

  In addition, for example, the number density of the LED light sources in the vicinity of the side light emitting LED light source 3B may be higher than the number density of the LED light sources in other parts of the same substrate 2, and the side light emitting LED light source is provided on the substrate 2. It may be said that there is a portion where the number density of the LED light sources is lower than that in the vicinity of 3B.

  FIG. 18A is a front view for explaining the configuration of the illumination device according to the sixth embodiment of the present invention, as viewed from the normal direction of the substrate 2 on which the LED light source 3A and the LED light source 3B are mounted. It is a figure. The description of the same portions as the first embodiment or the portions having the same functions is omitted. The definitions of the front direction Z and the side direction are as described in the first embodiment. FIG. 18B is a cross-sectional view taken along the line AA ′ of FIG. FIG. 18B shows a detailed shape not shown in FIG. 18A.

  In this example, the LED light source 3B disposed on the outermost side of the substrate 2 is a front-emitting LED light source, and the second optical member 6 is disposed corresponding to the LED light source 3B. The second optical member 6 is configured to guide most of the light incident from the incident surfaces 6A and 6A ′ in the side surface outward direction X.

  As indicated by the light ray RAY23, the light incident from the incident surface 6A propagates in the side surface outward direction X because the incident surface 6A is disposed outside the LED light source 3B and is directed outward from the LED light source 3B. Then, the light exits from the exit surface 6B outside the entrance surface 6A and irradiates the side surface portion 8B of the diffusion cover.

  The feature of the second optical member 6 is that the incident surface 6A is disposed outside the LED light source 3B. Further, the emission surface 6B is arranged on the outer side in the side surface direction of the incident surface 6A corresponding to the incident surface 6A. In this case, the light emitted from the first optical member 5 has more light flux in the front direction than the light emitted from the second optical member 6.

  Further, the light guide 6L is provided to propagate the light, and the emission surface 6B is arranged outside the end 2E of the substrate.

  The light ray RAY 24 will be described. The light ray RAY24 heading in the front direction Z from the LED light source 3B is incident on the second optical member 6 from the incident surface 6A ′ and guided outward by the reflecting surface 6C that reflects the light in the lateral direction outer side X. The ray RAY24 is totally reflected by the reflecting surface 6C. When the incident angle of light on the reflecting surface 6C is less than the critical angle, the reflection is not total reflection but Fresnel reflection. The shape of the reflecting surface 6C will be described in detail below. The light beam is guided through the light guide portion 6L and emitted from the emission surface 6B, and irradiates the side surface portion 8B of the diffusion cover. In this example, it is used as a method of reflecting total reflection and Fresnel reflection at the interface between air and a member, but it may be reflected by another method such as application of an aluminum thin film or a reflection sheet. Further, the reflecting surface 6C is preferably a specular reflecting surface in order to guide reflected light.

  The reflection surface 6 </ b> C that reflects light in the lateral side direction X of the present embodiment is inclined by about 45 degrees with respect to the front direction Z. From the viewpoint of reflecting the light in the lateral direction X, the reflecting surface 6C reflects the light propagating in the front direction Z. Therefore, it is preferable that the reflecting surface 6C is inclined at least 20 degrees with respect to the front direction Z, and 45 degrees is the most. good. Also, it may be 45 degrees or more, but if the angle is increased, the size of the front direction Z of the second optical member becomes larger, so that not only the optical viewpoint but also the productivity and weight in injection molding are increased. From the viewpoint, it is most desirable to set the angle to about 45 degrees. A desirable range is about 30 to 60 degrees.

  The normal 6CN of the reflection surface is configured to be inclined in the direction opposite to the lateral direction outer side X with respect to the front direction Z. The reflecting surface 6C is disposed to face the light emitting surface 3BE of the LED light source 3B in order to reflect most of the light from the LED light source 3B to the outer side X. The reflective surface 6C is arranged in the normal direction of the light emitting surface 3BE.

  Moreover, although the cross-sectional shape of the reflective surface 6C of this Embodiment is a linear shape, it is not limited to this, A broken line or a curve may be sufficient. What is necessary is just to have a function which reflects the light which goes to the front direction Z from LED light source 3B to the side direction outer side X. FIG. The surface having such a function is a surface having a portion in which the normal of the surface is inclined in a direction opposite to the lateral direction outer side X with respect to the front direction Z.

When a front-emitting LED light source is used as an LED light source that mainly irradiates the side surface portion 8B of the diffusion cover, light is emitted not only in the lateral direction outer side X but also toward the inner side. Therefore, as compared with the case where the side-emitting LED light source is used, the ratio of the luminous flux toward the outer side X in the side direction per LED light source is reduced. On the other hand, the ratio of the light emitted in the lateral direction inner side and the front direction Z increases.
Therefore, there is an effect on the problem that the front portion 8A of the diffusion cover in the front direction of the LED light source 3B becomes dark.

  Further, since an LED light source equal to the LED light source corresponding to the first optical member 5 can be used, the mounting process of the LED light source on the substrate 2 is simplified, the wiring of the LED light source is shared, and the drive circuit There are effects such as simplification. In particular, when the same LED light source is used, since the relationship between the current and the brightness is equal during dimming to change the brightness, it is possible to change the brightness at the exact same ratio in the side surface portion 8B and the front surface portion 8A. It becomes possible.

  Further, two or more types of LED light sources having different color temperatures are appropriately arranged, and the color of the emitted light of the lighting device may be adjusted by adjusting the input current between each type. When performing the toning, the ratio of the color type of the LED light source corresponding to the first optical member 5 and the ratio of the color type of the LED light source corresponding to the second optical member 6 are made equal. By controlling the current supplied to each type of LED light source equally between the LED light source 3A and the LED light source 3B, it is possible to perform color matching while making the colors of the emitted light from the front surface portion 8A and the side surface portion 8B equal. Become. For example, when two types of LED light sources having a color temperature of 3000K and 6000K are used, half of the LED light source 3A is a 3000K LED light source and the other half is a 6000K LED light source. Similarly, half of the LED light source 3B is an LED light source of 3000K, and the other half is an LED light source of 6000K, and the LED light source 3A and the LED light source 3B have the same color type ratio. The same current may be supplied to the LED light sources of the same color in the first optical member 5 and the second optical member 6.

  The light ray 25 will be described. The ray RAY25 is a ray emitted from the LED light source 3B in an oblique direction inclined with respect to the front direction Z. This light beam is an example of a light beam that enters from the incident surface 6A ′, is refracted by the reflecting surface 6C, and travels in the front direction Z. In this example, the reflective surface 6C is inclined about 45 degrees with respect to the front direction Z. When the inclination angle of the reflecting surface 6C is about 45 degrees, the light beam coming from the LED light source toward the front direction is efficiently reflected to the outer side X in the side surface direction. On the other hand, for the light emitted from the LED light source toward the inner side in the lateral direction than the front direction Z, there is also an effect that the light is refracted and the light is efficiently emitted in the front direction Z. By emitting light in the front direction Z, there is an effect of brightening the front portion 8A of the diffusion cover in the front direction Z of the LED light source.

  By controlling the shape of the reflecting surface 6C, it is possible to control the light fluxes in the lateral side direction X and the front direction Z. For example, the control can be performed by setting the cross-sectional shape of the reflective surface 6C to a polygonal or curved lens shape instead of a straight line.

  The cross-sectional shape of the emission surface 6B is a straight line, but is not limited to this, and various shapes described in the first and second embodiments can be used, and the effects described in the drawings are similarly obtained. Play.

  In this configuration, an optical member that guides light emitted in the front direction Z from the LED light source disposed on the outermost side to the outer side in the side surface direction is arranged correspondingly at a portion on the outer periphery of the substrate, and the optical member is arranged on the side surface. This is a member configuration that emits more light to the outside than the inside in the direction. Here, the inner side and the outer side in the side surface direction are defined with reference to the front direction Z of the position where the corresponding LED light source is arranged. When the propagation direction of the light beam is directed toward the outside X with respect to the front direction Z, the light is directed toward the outside. On the other hand, when the propagation direction of the light beam is directed inward (−X direction) with respect to the front direction Z, the light is directed inward. Here, the LED light source arranged on the outermost side can be said to be the LED light source closest to the edge of the substrate at a location on the outer periphery of the substrate.

  The first optical member 5 has a symmetrical shape on the outer side and the inner side in the lateral direction with respect to the position where the LED light source is disposed. On the other hand, the second optical member 6 has an asymmetric shape on the outer side and the inner side in the lateral direction with respect to the position where the LED light source is disposed. The second optical member 6 has a configuration in which the center of gravity is outside the LED light source. These features are features for emitting more light to the outside.

  As described in the present embodiment, the front-emitting LED light source can be used as a light source corresponding to a member that mainly irradiates the side surface portion 8B of the diffusion cover 8 with light. That is, even when a front-emitting LED light source is used as the LED light source corresponding to the second optical member that is a member that efficiently irradiates the side surface portion 8B described in the first to fifth embodiments, the present embodiment If it is an illuminating device provided with the feature of a form, it is possible to irradiate the side part 8B efficiently similarly.

  Next, the role of the protective cover of the composite optical member 7 will be described with reference to FIG. Basically, also in this embodiment, as described in the first embodiment, since the composite optical member 7 covers the electrode 40, it also functions as a protective cover. FIG. 19 is a supplementary explanation, especially when the electrodes are not completely covered.

FIG. 19 shows a configuration in which a gap 7 </ b> G exists between the second optical member 6 and the optical member connecting portion 4. The width 7W of the gap 7G is about several mm, and is such a width that a hand does not touch the electrode.
Therefore, it has a function of a protective cover that prevents a person from touching the electrode 40 and receiving an electric shock.

  The gap 7G has one effect of improving efficiency by providing the gap 7G and allowing light to pass through because the light absorption is not completely zero no matter what material the composite optical member 7 is made of. .

  In this example, it is provided due to a manufacturing problem. The composite optical member 7 of the illumination device of this example is manufactured by injection molding at a time. If there is a thin part in the shape, the resin will not flow in and it will not be possible to mold cleanly. In addition, such a portion is weak in strength, and cracks are also generated. Therefore, it is molded so as not to be less than 1 mm as much as possible. We want to secure at least 0.5mm.

  The space between the second optical member 6 and the optical member connecting portion 4 is thin. This is because the normal 6CN of the reflecting surface is inclined in the direction opposite to the lateral direction outer side X (even in a portion where the optical member connecting portion 4 and the second optical member 6 having different thicknesses in the front direction are connected). This is because there is a space for disposing the LED light source 3B. Therefore, in order to prevent the portion of the composite optical member 7 from becoming too thin, it is deleted before the portion becomes less than a predetermined thickness to form the gap 7G. Between the 2nd optical member 6 and the optical member connection part 4, it connects so that the composite optical member 7 may not become thin in another site | part in a board | substrate surface. Therefore, by providing the gap 7G, the effect of facilitating manufacturing is produced.

  FIG. 20 is a cross-sectional view for explaining the configuration of a lighting apparatus according to the seventh embodiment of the present invention. The description of the same portions as the first embodiment or the portions having the same functions is omitted. The difference from the first embodiment is that a front-emitting LED light source is used instead of a side-emitting LED light source as the LED light source located on the outermost side in the side-surface direction. Moreover, in order to irradiate efficiently the side part 8B of the diffusion cover 8, the 2nd optical member 6 is installed corresponding to the said LED light source 3B.

  The second optical member 6 does not have a light guide part, and is an optical member having a different shape from the first optical member 5 and a different luminous intensity distribution of the emitted light. The LED light source 3A and LED light source 3B of the illumination device 1 of this example are front-emitting LED light sources. Especially in this example, all the LED light sources arrange | positioned at the illuminating device 1 are set as the front light emission LED light source. The LED light source 3A corresponding to the first optical member 5 may be the same as or different from the LED light source 3B corresponding to the second optical member 6. In this example, it is assumed that the LED light source 3A and the LED light source 3B are equal. In this example, the second optical member 6 is installed corresponding to the two outer LED light sources 3B.

  As in the first embodiment, the main purposes are to increase indirect light and to make the illuminance of the diffusion cover 8 uniform. The point where the diffusion cover 8 near the center C of the lighting device becomes dark, and the diffusion cover 8 between the end 2E of the substrate 2 and the side surface part 8B of the diffusion cover (referred to as a diffusion cover peripheral part) becomes dark. By improving the points, there is provided an illuminating device that uniformly illuminates the entire diffusing cover 8 and that increases the light distribution of the illuminating device 1 and increases indirect light by brightening the periphery of the diffusing cover.

  As described in the first embodiment, since the fixture 51 is provided, the LED light source 3 cannot be placed at the center of the lighting device 1. Therefore, the diffusion cover 8 near the center C of the lighting device becomes dark. In addition, a fixed space is required between the end 2E of the substrate 2 and the side surface 8B of the diffusion cover in order to install a fixture (not shown) for fixing the diffusion cover 8 to the frame 11. (See FIG. 20). Therefore, there is a limit in bringing the LED light source closer, and the periphery of the diffusion cover becomes dark.

  In general, the diffusion cover 8 has a height Hc near the center C higher than a height He near the end 2E of the substrate. Therefore, when the optical members near the center C and the end 2E of the substrate are equal, the light emitted from the optical member near the center C is diffused more than the light emitted from the optical member near the end 2E of the substrate. It spreads until it reaches the cover 8. That is, light diffuses. Therefore, in the vicinity of the center C, it is not necessary to extremely spread the light with the optical member. For example, it is often unnecessary to use a lens whose luminous intensity peak exceeds 80 degrees. Further, if the light is spread too much, the light does not efficiently reach the diffusion cover 8 near the center C, and the dark part of the portion of the diffusion cover 8 cannot be improved. For example, if the distance between the LED light source 3A closest to the center C and the center C is Dp1, light may be emitted at a wider angle than the angle obtained by ATRAN (Dp1 / Hc). It is preferable that there is a light intensity peak at an angle of Atan (Dp1 / HC) +5 degrees to 20 degrees.

  On the other hand, since the optical member in the vicinity of the end 2E has a low height He, it is better to emit light in as wide a range as possible.

  Therefore, the luminous intensity of the emitted light of the second optical member 6 corresponding to the LED light source 3B located on the outermost side from the luminous intensity distribution of the emitted light of the first optical member 5 corresponding to the LED light source 3A near the center C. A wider distribution is effective for making the illuminance of the diffusion cover 8 uniform. This effect is particularly effective when the height Hc near the center C is higher than the height He near the edge 2E of the substrate.

  In this example, the second optical member 6 is disposed for the two LED light sources 3B on the outer side in the side surface direction. This is because LED light sources other than the LED light source 3A in the vicinity of the center C do not need to emit light toward a specific portion of the diffusion cover 8, so that the light is emitted in as wide a range as possible. This is because it is better to make the illuminance uniform.

  That is, the first optical member 5 is disposed so as to surround the center C, and is the optical member near the center of the lighting device 1, particularly the optical member closest to the center of the lighting device 1. The point that becomes darker has been improved. Furthermore, by arranging the second optical member 6 along the edge 2E of the substrate, the periphery of the diffusion cover is brightened, the light distribution of the lighting device 1 is expanded, and indirect light is also increased. Further, by making all the optical members outside the first optical member 5 into the second optical member 6 in the side surface direction, it contributes to uniformization of the entire diffusion cover 8.

  Here, the role of the optical member connecting portion 4 plays a plurality of roles described in the first embodiment.

  When the number of LED light sources included in the illuminating device 1 exceeds several tens, it is time consuming to attach and align the optical members individually, which is not desirable from the viewpoint of power saving and work cost. Incidentally, in the case of a room application wider than a living room with a lighting device attached to the ceiling, usually several tens or more LED light sources are required.

  However, in the case of a composite optical member in which a plurality of optical members are combined as in this example, there is an effect that the number of mounting operations is reduced. Furthermore, when all the optical members are made by batch molding as in this example, the time required for attachment is remarkably improved. Further, when there are a plurality of types of optical members, when a batch-molded composite optical member is attached, there is an effect that there is no mistake in attaching the optical member to the corresponding LED light source. Further, as in this example, when the LED light sources are all front-emitting LED light sources and the LED light source 3A and the LED light source 3B are equal, the shapes of the first optical member 5 and the second optical member 6 are different, Since there are similarities, mistakes are likely to occur during installation. Therefore, the batch-molded composite optical member is more effective in this example.

  Next, the arrangement of the LED light source of this example will be described with reference to FIG. FIG. 20 shows the minimum necessary for the explanation, and the LED arrangement is omitted from the case of FIG. For example, as will be described later, the LED light source of FIG. 21A is arranged as seven concentric circles, but in FIG. 20, it is drawn as a sectional view of three concentric circles. Further, FIG. 21A describes the color described later, but FIG. 20 does not describe the color information of the LED light source. This is to avoid the complexity of FIG. 20 and the description. FIG. 21A is described in order to explain the arrangement and color of the LED light source in more detail.

  FIG. 21A is a front view seen from the normal direction of the substrate 2 on which the LED light sources 3A and 3B are mounted. The substrate 2 has a shape in which a circle is divided into four, and four identical substrates are arranged. In the figure, the optical member is written on only one substrate. An optical member is disposed corresponding to each LED light source. The optical members 501 and 502 are the first optical members 5 having the same shape, and the colors of the corresponding LED light sources are different. The optical members 601 and 602 are the second optical members 6 having the same shape, and the colors of the corresponding LED light sources are different.

  FIG. 21B shows an enlarged view of the first optical member. As shown in FIG. 21B, the first optical member 5 is isotropic when viewed from the normal direction of the substrate 2 and is circular when viewed from the front.

  An enlarged view of the second optical member 6 is shown in FIG. The second optical member 6 has an anisotropic shape when viewed from the normal direction of the substrate 2, and has a shape composed of a circle and a straight line when viewed from the front. Here, the shape of the second optical member 6 in a front view is not limited to a circle and a straight line. It may be a curved line or a broken line. For convenience, when a polar coordinate system with the center C as the origin is considered, the second optical member 6 is different in cross-sectional shape between the radial direction Rdir and the azimuthal direction Cdir perpendicular to the radial direction. The width 6W2 in the azimuth direction (circumferential direction) is larger than the width 6W1 in the direction. In other words, it can be said that the width in the direction in which the LED light sources are closely arranged (directions in each direction) is larger than the width in the direction perpendicular to the direction.

  Each LED light source surrounds the center C. The same optical member is arranged in a circle having substantially the same distance from the center C. In this example, LED light sources are arranged in seven concentric circles having the same center. Let the radius of each concentric circle be Dp1 to Dp7. Each circle is marked with a dotted line in the figure.

  In the circle closest to the center C, the first optical members 501 and 502 are arranged. Second optical members 601 and 602 are arranged on the outer circle. Further, the luminous intensity distribution of the emitted light of the second optical members 601 and 602 located on the outermost side is wider than the luminous intensity distribution of the emitted light of the first optical members 501 and 502 near the center C. Thus, the configuration is effective for making the illuminance of the diffusion cover 8 uniform. The reason is the same as described with reference to FIG.

  The second optical member 6 corresponds to a circle other than the circle closest to the center C. In other words, the first optical member 5 is disposed at an end portion on the side close to the center C of the substrate so as to surround the center C, and is farther from the center C than the position surrounded by the first optical member 5. The optical member arranged in the second optical member 6 is configured as the second optical member 6.

  This is because there is no need to emit light toward a specific part of the diffusion cover 8 for optical members other than the optical member near the center C. This is because it is better to equalize.

  The relationship between the color and arrangement of the LED light source will be described. In this example, the LED light sources corresponding to the optical members 501 and 601 are the same. Further, the LED light sources corresponding to the optical members 502 and 602 are assumed to be equal. At least, the emitted light from the first optical members 501 and 502 must be mixed. Moreover, the emitted light from the second optical members 601 and 602 must be mixed. If the colors are not mixed, the color of the diffusion cover 8 is not uniform and color unevenness occurs. Therefore, it is preferable to arrange LED light sources having different colors adjacent to each other so as to facilitate color mixing.

  In addition, when n-color LED light sources are used, it is preferable to use different LED light sources for one type of optical member. This is because the same optical member has the same light distribution, so that it is easier to make the color uniform. In this example, a two-color LED light source is used for the first optical member 5, and a two-color LED light source is also used for the second optical member 6.

  The arrangement of the LED light sources along the end portions 2ER1 and 2ER2 that are the boundaries between the substrates of the substrate 2 will be described. The end has two sides, and on either side, the corresponding LED light source from the innermost first optical member 5 to the outermost second optical member 6 along the ends 2ER1 and 2ER2. The colors are alternately different. For example, the one end 2ER1 is arranged such that the second optical members 601 and 602 are 602, 601, 602, 601, 602, and 601 in the radial direction from the center C after the first optical member 501. The colors of the corresponding LED light sources are different. Further, the end 2ER2 on the opposite side has a color different from that of the LED light source of the first optical member 502 and the end 2ER1, and then the second optical members 601 and 602 are 601 602 601, The colors of the LED light sources corresponding to 602, 601 and 602 and alternately corresponding to the radial direction from the center C are different.

  In other words, the illuminating device is configured by a plurality of substrates, and in the end two sides 2ER1 and 2ER2 which are boundaries between the substrates, the second optical device that is farthest from the center C from the first optical member closest to the center C The colors of the corresponding LED light sources are alternately arranged up to the optical member.

  Further, at the two edges that are the boundary, the order of colors in the direction away from the center C of the LED light source arranged along one side and the center C of the LED light source arranged along the other side. The order of the colors in the direction away from is different.

  By adopting such a configuration, even when the lighting device is configured using the same substrate 2, the color of adjacent LED light sources is different at the boundary between different substrates even when the boundary is sandwiched. Therefore, color unevenness can be suppressed even when the lighting device is configured using substrates of the same design.

Next, the optical member will be described in detail. First, the cross section of the first optical member 5 and the cross sectional shape of the second optical member 6 in the radial direction Rdir will be described with reference to FIGS.
22A is a cross-sectional view of the first optical member 5, and FIG. 22B is a cross-sectional view of the second optical member 6 in the radial direction Rdir. The first and second optical members are lenses, and the lens includes an inner surface Lu facing the LED light source and a lens surface Lo that emits light to the outside of the lens. The inner surface Lu has an inclined portion Tp. In the figure, ray RAYS is shown for reference. The second optical member 6 refracts the emitted light from the LED light source to a larger angle and widens the light distribution angle.

  FIG. 22C is a diagram for explaining the optical system of the second optical member 6, and only the inner surface Lu facing the LED light source is different from the second optical member 6 and includes an inclined portion Tp. There is no cross-sectional shape of the lens. The effect of the inclined portion Tp will be described. As indicated by the ray RayL in FIG. 22 (c), when there is no inclined portion Tp, the emitted light having a large polar angle out of the light emitted from the LED light source enters the optical member connecting portion 4 and is guided. Shine.

  In some cases, light is actively incident on the optical member connecting portion 4 to guide the light, but in this example, the first optical member 5, the second optical member 6, and the optical member connecting portion 4 are not guided. One of the purposes is to emit light from the composite optical member 7 made of the above. The reason for this is that when light is guided through the composite optical member 7, an optical system that appropriately takes out light from the composite optical member 7 and suppresses the loss of light is necessary. Since it is assumed that the system is not mounted, if light is guided through the composite optical member 7, stray light may be partly lost.

  Since the second optical member 6 shown in FIG. 22B has the inclined portion Tp, the ray RayL from the LED light source 3B toward the optical member connecting portion 4 is refracted toward the lens surface Lo by the inclined portion Tp. The Therefore, the amount of light that enters and guides the optical member connecting portion 4 is less than that when there is no inclined portion Tp. Therefore, the inclined portion Tp has an effect of suppressing light that enters and guides the optical member connection portion 4 and reduces optical loss.

  The angle of the inclined portion Tp from the substrate normal is about 50 to 75 degrees. The inner surface Lu is preferably a spherical surface from the viewpoint of design. By using a spherical surface, the lens surface Lo can be designed for the light emitted from the point light source located at a specific position. However, the spherical surface is not a shape that suppresses the light emitted from the LED light source toward the optical member connecting portion 4, and is a surface that refracts the emitted light of a certain angle or more from the LED light source toward the lens surface Lo. The inner surface Lu is configured by continuously connecting the inclined portion Tp with the spherical surface portion. That is, the cross-sectional shape of the inner surface Lu is composed of a curve and a straight line.

The position where the surface that refracts the emitted light from the LED light source at a certain angle or more toward the lens surface Lo starts is at the center of the lens at the height of the light emitting surface of the LED, and light is emitted from the origin. Assuming that, the angle from the lens central axis is approximately 70 to 80 degrees, and the spherical surface of the lens inner surface extends to the surface facing the side surface of the LED light source as shown in FIG. Sometimes (when the inner surface is not spherical, when the end of the inner surface is extended as it is), the point where the spherical surface intersects is the starting point. The inner surface of the lens closer to the substrate 2 than the starting point may be a surface that is refracted toward the lens surface Lo. Considering another point, the spherical surface of the lens inner surface is an LED light source as shown in FIG. (When the inner surface is not spherical, when the end of the inner surface is extended as it is), the light from the above-mentioned origin does not exit from the lens surface Lo. It is only necessary to obtain a polar angle incident on the optical member connecting portion 4 and provide a surface that refracts the emitted light with the polar angle or more toward the lens surface Lo.

  In this example, the inclined portion Tp is a straight line because it can be designed easily. However, the present invention is not limited to this, and the light emitted from the LED light source with a certain angle or more is smoothly directed to the lens surface Lo from a spherical portion. It is also possible to design the surface to be refracted. In that case, the curvature of the curve changes from the vicinity of the start point described above.

  Next, the shape of the second optical member 6 in the azimuth direction Cdir will be described with reference to FIGS. FIG. 23A is a diagram of the azimuth angle direction Cdir of the second optical member 6. As shown in FIG. 23A, the cross section in the azimuth direction Cdir has a straight line portion having a length Lg at the center, and other portions are the same as the cross section in the radial direction Rdir. That is, in FIGS. 22B and 23A, the shapes Loa-Lob and Lua-Lub are the same shape. The cross section in the azimuth direction Cdir is longer than the cross section in the radial direction Rdir by the straight line portion Lg. 6W2 = 6W1 + Lg.

  The three-dimensional shape of the lens surface Lo is shown in FIG. The Loa, which is the start point of the curve, and the Lob, which is the end point, are shown in the figure. A flat portion indicated by Ltp exists at the center. The curved shape Loa-Lob, which is a part of the cross-sectional shape of the second optical member, is the same shape over the entire periphery of the lens.

  The reason why the second optical member 6 has this lens shape is that the cross-sectional shape in the radial direction Rdir is a shape that spreads light in a wide angle, and the azimuth direction Cdir is a cross-sectional shape that does not spread light in a wide angle. It became this shape. First, the cross-sectional shape of the radial direction Rdir is determined, and then the azimuth angle direction Cdir increases the luminous intensity in the normal direction of the substrate by introducing a straight portion having a length Lg at the center portion, thereby widening the angle. The amount of emitted light was reduced. If the cross-sectional shapes of the radial direction Rdir and the azimuth direction Cdir are not continuously connected, the light distribution becomes discontinuous and causes unevenness. Therefore, the cross-sectional shapes of the radial direction Rdir and the azimuth direction Cdir are continuous. Therefore, the cross-sectional shape in the azimuth direction Cdir is equal to the cross-sectional shape in the radial direction Rdir except for the straight portion.

  By providing this feature, the cross-sectional shape of the radial direction Rdir and the azimuth direction Cdir are continuously connected and the unevenness is suppressed while the light distribution characteristic has anisotropy within a desired mounting surface. Have

  Here, the reason why the cross-sectional shape in the radial direction Rdir is a shape that spreads light at a wide angle and the azimuth angle direction Cdir is a cross-sectional shape that does not spread light at a wide angle will be described. Regarding the radial direction Rdir, it is necessary to spread light and irradiate a large amount of light around the diffusion cover to improve unevenness and increase indirect light. On the other hand, since the LED light source is disposed adjacent to the azimuth direction Cdir, it is not necessary to emit light at a wide angle. In general, a lens that emits light at a wide angle tends to be sensitive to a positional shift between the lens and the LED light source, and a luminous intensity peak may interfere between adjacent optical members and become uneven. Therefore, the azimuth angle direction Cdir in which the LED light sources are arranged adjacent to each other has a lens configuration that does not emit light at a wide angle. The unevenness which occurs is suppressed.

Therefore, as shown in FIG. 21, in the shape of the second optical member 6, the width in the direction in which the LED light sources are densely arranged is larger than the width in the direction perpendicular to the direction.
The second LED light sources are arranged in a substantially circular shape, and when the second optical member 6 is viewed from the normal direction of the substrate 2, the shape of the second optical member 6 is the azimuth angle direction. Different in Cdir and radial direction Rdir, the width in the azimuth direction Cdir is larger. As described above, the second optical member 6 closest to the end portion 2E of the substrate 2 is formed in an anisotropic shape when the member is viewed from the normal direction of the substrate 2 as described above. While suppressing various unevenness and emitting light at a wide angle, the periphery of the diffusion cover is brightened to broaden the light distribution of the lighting device, and indirect light is also increased.

  Here, the light distribution angles of the first optical member 5 and the second optical member 6 will be described in detail with reference to FIG. The horizontal axis of the graph of FIG. 24 represents the polar angle which is an angle from the normal line of the board | substrate 2 which mounts an optical member. The vertical axis represents the normalized luminous intensity obtained by normalizing the luminous intensity with the total luminous flux of the light emitted from the optical member.

  The luminous intensity distribution I1a of the first optical member 5 has a luminous intensity peak between approximately 60 degrees and 65 degrees, and the luminous intensity sharply decreases when the angle is larger than the luminous intensity peak. The luminous intensity distribution I1a of the first optical member 5 is a luminous intensity distribution in which the luminous intensity distribution of Lambertian emitted from the LED light source 3A has a luminous intensity peak in the direction of approximately 60 degrees as compared with the case where the first optical member 5 is not provided. So that the light is spread over a wide angle.

  Similarly, the luminous intensity distribution I2r in the radial direction Rdir of the second optical member 6 has a luminous intensity peak at approximately 75 degrees, and the luminous intensity sharply decreases at an angle larger than the luminous intensity peak. The light intensity distribution I2r spreads the light over a wide angle so that the light intensity distribution of Lambertian emitted from the LED light source 3B becomes a light intensity distribution with a light intensity peak in the 75 degree direction. Compared to the Lambertian luminous intensity distribution (not shown), the luminous intensity at 0 degree is low and the luminous intensity in the 75 degree direction is large. The light intensity distribution I2r is characterized by a low angle of 0 to 45 degrees, a small intensity, and a peak at a wide angle that is approximately equal to or greater than the intensity near 0 degrees. It can be seen from this distribution that light rays are emitted at a wide angle up to the luminous intensity peak.

  On the other hand, the luminous intensity distribution I2c of the second optical member 6 in the azimuth angle direction Cdir decreases as the 0 degree direction increases and the polar angle increases. However, there is a small peak around 80 degrees. Since this peak has a sufficiently small value compared to the front direction (0 degree), there is almost no influence. Furthermore, the light intensity in the region of 50 to 75 degrees is low, and there is only a small peak around 80 degrees. The small peak of 80 degrees is the outgoing light in the azimuth direction Cdir, and is diffused and influenced by the propagation of a longer distance than the outgoing light in the radial direction Rdir before reaching the diffusion cover 8. Disappears. Therefore, it can be seen that the light intensity distribution I2c emits light in a narrower range than the light intensity distribution I2r.

  When the luminous intensity distribution I2r in the radial direction Rdir of the second optical member 6 is compared with the luminous intensity distribution I1a of the first optical member 5, the luminous intensity peak of the luminous intensity distribution I2r is at a wider angle, and the luminous intensity distribution I1a has the luminous intensity distribution I1a. Since the luminous intensity distribution I2r has a high value in a region that is sharply reduced at a wide angle, the luminous intensity distribution of the emitted light from the second optical member 6 in the cross section in the radial direction Rdir is It can be said that the light intensity distribution of the light emitted from the optical member 5 is wider.

  The first optical member 5 was an isotropic optical member. Since the first optical member 5 has a narrower light distribution angle than the second optical member 6, unevenness due to positional deviation between the lens and the LED light source is less likely to occur. Therefore, it is not necessary for the first optical member 5 to have an anisotropic lens shape. In addition, in order to emit as much light as possible to the dark part near the center C, it is desirable to arrange many LED light sources along the edge of the substrate 2 near the center C. Therefore, the LED light sources were arranged as densely as possible in the isotropic lens shape, not the anisotropic lens shape long in the azimuth direction Cdir. When the optical member closest to the center is seen from the normal direction of the substrate 2 to have an isotropic shape, the optical member has a higher density than the LED light source disposed outside the LED light source. It is possible to improve the dark part by arranging an LED light source and emitting a lot of light to the dark part near the center C.

  Therefore, the second optical member 6 having a light distribution angle exceeding 70 degrees has an anisotropic lens shape, and the first optical member 5 having a narrower light distribution angle than the second optical member 6 is isotropic. By adopting a typical lens shape, the diffusion cover 8 near the center C of the lighting device becomes dark while suppressing unevenness due to the positional deviation between the lens and the LED light source, and the end 2E of the substrate 2 and the diffusion cover The diffusion cover 8 (referred to as the diffusion cover peripheral portion) between the side surface portions 8B of the first and second side portions 8B has been improved. Accordingly, the illumination device is provided that uniformly illuminates the entire diffusion cover, and that the periphery of the diffusion cover becomes bright, thereby widening the light distribution of the illumination device and increasing indirect light.

  Next, the relationship between the LED arrangement in the LED light source and the anisotropic lens arrangement will be described with reference to FIGS. First, a preferable LED arrangement in the LED light source and an anisotropic lens arrangement relationship will be described with reference to FIG. In this example, the LED light source 3 </ b> B has three LEDs 30 mounted on the mounting surface 37 a of the frame body 37. The radial direction Rdir of the second optical member 6 is substantially equal to the direction in which the LEDs 30 are arranged. In other words, in the LED light source 3B, the direction in which the position distribution range in which the LEDs 30 are arranged is long and the radial direction Rdir are substantially in the same direction.

  In the LED light source 3B, the emitted light ELD from the light emitting surface directly above the LED 30 and the emitted light ELI from directly above the portion where the LED 30 is not provided are different in color. When the illuminance of one of the emitted light ELD or ELI becomes strong at a specific part of the diffusion cover 8, color unevenness occurs. In order to improve this color unevenness, the configuration of FIG. 25A is effective.

  This is because, in the case of an optical member that emits light with a wide light distribution, the light emission direction from the surface of the optical member strongly depends on the light emission position in the light emitting surface of the LED light source 3B at a wide angle. In the case of the second optical member 6, the radial direction Rdir emits light at a wide angle, but the azimuth direction Cdir does not emit light at a wide angle. Therefore, the LEDs 30 are arranged so that the emission color does not change as much as possible even if the emission position changes with respect to the radial direction Rdir direction.

  The effect of the positional relationship between the LED arrangement in the LED light source and the second optical member on the color unevenness will be described with reference to FIGS. FIG. 25B and FIG. 25C are cross-sectional views in the radial direction of the configuration of FIG. 25 (d) and 25 (e) are cross-sectional views in the radial direction when the LED light source 3B is rotated 90 degrees in FIG. 25 (a).

  First, FIG. 25B and FIG. 25D are compared. FIG. 25B shows a schematic diagram of the central LED and light rays emitted from directly above the LEDs 30 arranged on the right and left sides of the central LED in the figure. In FIG. 25 (d), an example of ray tracing is shown with the emission point of the ray equal to that in FIG. 25 (b). The light propagation direction is the same for both. In the case of FIG. 25B, all three light beams are the same color as the light beam ELD. On the other hand, in the case of FIG. 25 (d), since the LED is arranged only in the center, the emitted light from both sides of the LED is the emitted light ELI.

  Therefore, in the case of FIG. 25D, the colors are separated after exiting from the second optical member 6. Since the distance from the second optical member 6 near the end 2E of the substrate 2 that irradiates the periphery of the diffusion cover to the diffusion cover 8 is larger than the distance between the adjacent LED light sources, the color is diffused. Separation becomes large and color unevenness occurs. In addition, since the light emitted at a wide angle is incident on the lens surface Lo of the second optical member 6 at an angle close to the total reflection angle, the refraction angle is sensitive to the incident angle, and the colors are easily separated. Unevenness is likely to occur. Therefore, as shown in FIG. 25 (b), it is important to arrange the LEDs 30 so that the emission color does not change as much as possible even if the emission position changes in the radial direction Rdir direction.

  Furthermore, FIG. 25C and FIG. 25E will be compared to describe color unevenness due to another mode. The light emission positions in FIGS. 25C and 25E are equal to those in FIG. The difference is that light is emitted from the LED light source at a wider angle.

  In FIG. 25 (c), the light emitted from right above the central LED and the right LED in the figure is refracted by the inclined portion Tp and emitted from the lens surface Lo. The light emitted from the left LED in the figure is refracted at the curved portion of the lens inner surface Lu and is emitted from the lens surface Lo. The light propagating through these two paths has a significantly different angle of emission. In FIG. 25 (e), the propagation path of the light beam is equal to that in FIG. 25 (c). The light is emitted from the lens surface Lo at an angle different from that of the ELI. Therefore, the light ELI emitted from directly above the left side of the LED irradiates a specific position of the diffusion cover 8 alone, and causes color unevenness.

  This phenomenon also occurs in the azimuth angle direction Cdir of the second optical member 6, but the color unevenness is small as long as light is not emitted at a wide angle. Further, the LED light source is arranged close to the azimuth angle direction Cdir. Therefore, the emitted light is mixed between adjacent LED light sources, and color unevenness does not occur.

  Therefore, the direction perpendicular to the direction in which the LED light source 3B is arranged close to the lens is a wide-angle light distribution, and the position distribution range in which the LEDs 30 are arranged in the LED light source 3B is longer than the vertical direction. By setting the directions to be approximately equal, color unevenness is suppressed. In other words, when the second optical member 6 is viewed from the normal direction of the substrate 2 when the direction in which the position distribution range in which the LEDs are arranged is long is the LED arrangement direction, the second optical member 6 is seen. Regarding the shape of the member 6, it can be said that the width in the direction parallel to the LED arrangement direction is smaller than the width in the direction perpendicular to the direction. In addition, it can be said that the direction in which the position distribution range in which the LEDs are arranged is long is arranged in parallel to the direction from the center of the illumination device to the outside.

  The direction AL in which the position distribution range in which the LEDs 30 are arranged is long will be described with reference to FIGS. 25 (f) and 25 (g). The LEDs 30 are not necessarily arranged in a line as shown in FIG. As shown in FIG. 25 (f), there is a case where they are arranged slightly out of line. The direction AL can be defined using the side wall direction of the side wall 37b of the frame of the LED light source. Since the frame of the LED light source 3B is usually rectangular, the side wall directions of the side walls 37b are two orthogonal directions. In the case of FIG. 25 (f), the position distribution range in which the LEDs 30 are arranged is longer in the direction parallel to one of the side walls 37b indicated by the arrow than in the direction orthogonal to the direction indicated by the arrow. The arrow direction can be defined as the direction AL.

  In the case of FIG. 25G, the positions of the LEDs 30 are distributed in an oblique direction with respect to the side wall 37 as indicated by the dotted arrows. The dotted arrow may be the direction AL, but more simply, it may be determined in two directions of the side wall 37b as in the case of FIG. 25 (f), and is parallel to one of the side walls 37b indicated by the arrow in the figure. The direction can be defined as the direction AL.

  Further, as a method for eliminating further color unevenness, in the second optical member 6 described in this example, such as the configuration shown in FIG. 25A, the incident surface of the second optical member such as the inner surface Lu, or There is a method of imparting a diffusive shape to the exit surface of the second optical member such as the lens surface Lo. For example, it has a fine shape with smooth irregularities or a wrinkle shape. Color unevenness is reduced by imparting a diffusive shape.

  In each of the embodiments described above, a shape in which the front portion 8A and the side portion 8B can be clearly seen is used as the shape of the diffusion cover in order to explain the present invention. However, the present invention is not limited to the shape of the diffusion cover. If the light beam emitted from the second optical member in the side surface direction increases, the light beam in the side surface direction also increases as the lighting device, and the indirect light increases.

  In each of the embodiments described above, the features described in each embodiment can be applied independently, but can be used in appropriate combination.

  Each embodiment described above is a specific example shown for explanation of the present invention, and the present invention is not limited to each of these embodiments. For example, the shape and configuration of each member illustrated in the above embodiments should be appropriately designed or optimized as necessary as long as the function that the member should have is satisfied.

DESCRIPTION OF SYMBOLS 1 Illuminating device 2 Board | substrate 3 LED light source 4 Optical member connection part 5 1st optical member 6 2nd optical member 7 Composite optical member 8 Diffusion cover 9 Lighting circuit 10 Center cover 11 Frame 30 Light emitting diode (LED)
31 Negative electrode 32 Positive electrode 33 Phosphor 34 Sealing resin 35 Wire 36 (36 ') Mounting terminal 37 Frame 40 (40') Electrode 50 Ceiling 51 Fixing tool

Claims (5)

A substrate,
A first LED light source and a second LED light source mounted on the electrode on the substrate so as to surround the center of the lighting device ;
A first optical member corresponding to the first LED light source; a second optical member corresponding to the second LED light source; and an optical member connection connecting the first optical member and the second optical member. A lighting device having a composite optical member ,
The luminous intensity distribution of the outgoing light from the first optical member is different from the luminous intensity distribution of the outgoing light from the second optical member,
When the direction in which the lighting device mainly emits light is the front direction, and the direction substantially perpendicular to the front direction is the side direction,
The first LED light source and the second LED light source are front-emitting LED light sources that mainly emit light in the normal direction of the substrate,
The second LED light source is disposed at a position farther from the center of the lighting device than the first LED light source,
The luminous intensity distribution of the emitted light of the second optical member in the cross section including the center of the second optical member is the luminous intensity distribution of the emitted light of the first optical member in the cross section including the center of the first optical member. wider than said second optical member Ri lens der,
The illumination device has a light intensity distribution of outgoing light of the outermost optical member in the composite optical member wider than that of outgoing light of the innermost optical member .
The lighting device according to claim 1, wherein the first optical member is disposed near a center of the lighting device so as to surround a center of the lighting device.
The lighting device according to claim 1, further comprising a fixture for fixing the lighting device at a center of the lighting device.
The said 1st optical member when it sees from the normal line direction of the said board | substrate is an isotropic shape, The said 2nd optical member is a lens, The any one of Claims 1 thru | or 3 Lighting device.
The lighting device according to any one of claims 1 to 4, wherein the second optical member when viewed from the normal direction of the substrate has an anisotropic shape .

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