JP5588808B2 - LIGHT EMITTING DEVICE, LIGHTING DEVICE, AND DISPLAY DEVICE - Google Patents

Description

  The present invention particularly relates to a light emitting device that emits light emitted from a light source while controlling the light distribution of the incident light, an illumination device used for various illuminations using the light emitting device, and the illumination device. The present invention relates to a display device used as a means in combination with an illuminated member.

  2. Description of the Related Art Conventionally, a light emitting diode having a light emitting chip and a lens member that receives light emitted from the light emitting chip and refracts and emits incident light is known (for example, Patent Document 1). In the light emitting diode of Patent Document 1, a light emitting chip is arranged in a hollow portion formed inside a lens member. The lens member has an inner surface facing the hollow portion and a light incident surface on which light emitted from the light emitting chip is incident.

  Moreover, in patent document 1, in order to improve a diffusibility, the cavity part of a lens member is made into a cannonball shape. Accordingly, in Patent Document 1, since light can be refracted in a direction far from the central axis of the lens member on the light incident surface facing the cavity portion, light diffusibility can be improved.

  In recent years, with the downsizing of devices to which light emitting devices such as light emitting diodes are attached, there is an increasing demand for downsizing of light emitting devices. In general, when the light emitting element is made smaller, the amount of light emitted from the light emitting element is insufficient, and the illuminance on the irradiated surface is reduced. Therefore, in the light emitting device, in order to satisfy the demand for downsizing while preventing a decrease in illuminance on the irradiated surface, the light flux controlling member must be downsized without changing the size of the light emitting element.

JP 2006-114863 A

  However, in the light emitting diode of Patent Document 1, if the lens member is downsized without changing the optical characteristics, the cavity portion in which the light emitting chip is disposed is also reduced. As a result, there is a problem that the light emitting chip and the lens member around the hollow portion interfere with each other, and the light emitting chip cannot be disposed in the hollow portion.

  The object of the present invention is to arrange the light-emitting element at a predetermined position without reducing the size by making the incident surface formed into a bell shape to improve the diffusibility and further having a shape with the hem widened toward the opening edge. It is possible to provide a light-emitting device, a lighting device, and a display device that can achieve both improvement in light diffusibility and downsizing.

  The light emitting device of the present invention is arranged such that a light source mounted on a substrate and a central axis are positioned concentrically with the optical axis of the light source, and the light emitted from the light source is incident and the distribution of the incident light is arranged. A light-emitting device having a light-beam control member that controls and emits light, wherein the light-beam control member is formed by recessing a bottom surface and a part of the bottom surface inside and opening the bottom surface And an inner surface of the recess, an incident surface on which light emitted from the light source is incident, and an emission surface that emits light to the outside by controlling the light distribution of the light incident from the incident surface. The incident surface is line-symmetric with respect to the central axis in a cross section parallel to the central axis including the central axis, and the intersection point between the central axis and the light emitting surface of the light source is a reference point , A straight line connecting any point on the incident surface and the reference point A first region that is a first curve in which a distance r between an arbitrary point on the incident surface and the reference point decreases as an angle θr formed with the central axis increases; And a second curve or straight line that connects the point on the opening edge of the recess and the end point of the first curve, and increases the distance r as the angle θr increases. A configuration having a shape composed of a certain second region is adopted.

  The illuminating device of this invention takes the structure which has said light-emitting device and the to-be-irradiated surface irradiated with the light radiate | emitted from the said output surface of the said light-emitting device.

  The display device of the present invention employs a configuration having the above-described illumination device and a member to be illuminated that is illuminated by light emitted from the illumination device.

  According to the present invention, the incident surface formed in a bell shape for improving the diffusibility is further shaped toward the opening edge so that the hem is widened, so that the light emitting element can be arranged at a predetermined position without downsizing. Therefore, it is possible to achieve both improvement in light diffusibility and downsizing.

The top view of the light beam control member in embodiment of this invention The front view of the light beam control member in embodiment of this invention The bottom view of the light beam control member in embodiment of this invention Sectional drawing of the light-emitting device which concerns on embodiment of this invention The top view of the illuminating device which concerns on embodiment of this invention Sectional drawing of the display apparatus which concerns on embodiment of this invention The expanded sectional view of the principal part of the light beam control member in embodiment of this invention The enlarged view of the entrance plane of the light beam control member in embodiment of this invention The figure which shows the relationship between r and (theta) r in the entrance plane of the light beam control member in embodiment of this invention The figure which shows the relationship between (DELTA) r / (DELTA) (theta) r and (theta) r in the entrance plane of the light beam control member in embodiment of this invention. The figure which shows the course of the light of the light beam control member in embodiment of this invention

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
(Configuration of light emitting device)
Below, the structure of the light-emitting device 100 is demonstrated in detail using FIG. 1A-FIG. 1C and FIG. FIG. 1A is a plan view of light flux controlling member 150 according to the present embodiment. FIG. 1B is a front view of light flux controlling member 150 according to the present embodiment. FIG. 1C is a bottom view of light flux controlling member 150 according to the present embodiment. FIG. 2 is a cross-sectional view of the light emitting device 100 according to the present embodiment. In FIG. 2, the light flux controlling member 150 is shown cut along the line AA in FIG. 1C.

  The light emitting device 100 mainly includes a light flux controlling member 150, a light emitting element 200, and a substrate 210. The light flux controlling member 150 is mainly composed of a bottom surface 101, a concave portion 102, an incident surface 103, an exit surface 104, a flange portion 105, and a leg portion 106.

  The bottom surface 101 has a circular shape, and has a concave portion 102 for forming an incident surface 103 through which a light beam emitted from the light emitting element 200 enters the center portion of the circular shape. The bottom surface 101 is provided with three rod-like legs 106 along the outer periphery. Further, the bottom surface 101 is disposed substantially parallel to the substrate when the light flux controlling member 150 is mounted on the substrate 210.

  The recess 102 is formed by recessing the bottom surface 101 facing the light emitting element 200 inside, and opens to the bottom surface 101. The recess 102 is formed in a rotationally symmetric shape with respect to the central axis P1 (see FIGS. 1B and 2) of the light flux controlling member 150 that coincides with the optical axis of the light emitting element 200. In addition, the concave portion 102 has a bell shape as a whole, and is further formed in a shape in which the hem is widened toward the opening edge (see FIG. 2). Here, the central axis P <b> 1 passes through the center of a circular circle in plan view, is orthogonal to the radial direction of the circle, and is concentric with the optical axis of the light emitting element 200.

  The incident surface 103 is formed on the inner surface of the recess 102 and is formed to be rotationally symmetric about the central axis P1. Accordingly, the entrance surface 103 has a bell-like shape as in the case of the recess 102, and the skirt that approaches the outer periphery 110 in the radial direction of the circular shape in plan view becomes wider on the opening end side as it approaches the opening end of the recess 102. (See FIG. 2). Further, the light emitted from the light emitting element 200 is incident on the incident surface 103. Details of the configuration of the incident surface 103 will be described later.

  The emission surface 104 has a circular planar shape. Further, the emission surface 104 protrudes upward from the flange portion 105. The exit surface 104 includes a first exit surface 104a, a second exit surface 104b formed continuously around the first exit surface 104a, a second exit surface 104b, and a flange 105. It consists of the 3rd output surface 104c to connect (refer FIG. 2).

  The first light exit surface 104a has a smooth curved surface shape that protrudes downward, and has a concave shape obtained by cutting a part of a sphere. The second exit surface 104b is a smooth curved surface that is formed on the first exit surface 104a and is convex and has a substantially hollow disk shape that surrounds the first exit surface 104a. Formed. The third emission surface 104c is formed continuously with the second emission surface 104b.

  Further, the emission surface 104 controls light distribution by refracting or diffusing the light emitted from the light emitting element 200 and incident from the incident surface 103, and emits the light with controlled light distribution to the outside.

  The flange portion 105 is formed to protrude radially outward from the outer periphery of the emission surface 104 and has a substantially annular shape.

  The leg portion 106 is a leg for fixing the light flux controlling member 150 to a predetermined position and height with respect to the substrate 210, and is formed to protrude outward from the bottom surface 101. In addition, the leg portion 106 is formed around the concave portion 102 on the bottom surface 101. Further, three leg portions 106 are formed at intervals, and are provided at the positions of the vertices of the equilateral triangle on the bottom surface 101. Further, the leg 106 is fixed to the substrate by means such as an adhesive or welding in a state where the light flux controlling member 150 is positioned on the surface of the substrate 210. In addition, the number and arrangement | positioning of the leg part 106 are not restricted above, It can be made into arbitrary numbers and arbitrary arrangement | positioning.

  The light emitting element 200 is a light source such as a white light emitting diode and emits light to the outside.

  On the substrate 210, the light flux controlling member 150 and the light emitting element 200 are mounted.

(Configuration of lighting device and display device)
Below, the structure of the illuminating device 300 is demonstrated in detail using FIG.3 and FIG.4. FIG. 3 is a plan view of lighting apparatus 300 according to the present embodiment. FIG. 4 is a cross-sectional view of display device 500 according to the present embodiment. In FIG. 4, the illuminating device 300 shows what was cut | disconnected by the BB line of FIG. In FIG. 3, for convenience of explanation, description of optical members such as a diffusion plate, a diffusion sheet, and a prism sheet is omitted. Of the omitted optical members, the back surface of the optical member arranged closest to the light flux controlling member 150 (the surface facing the light flux controlling member 150) is the irradiated surface. Further, in FIG. 4, an optical member 401 configured by one or a plurality of members and constituting a part of the illumination device 300, and a liquid crystal panel as an illuminated member illuminated by light emitted from the illumination device 300 402 shows the display device 500.

  The illumination device 300 is mainly composed of the light emitting device 100, the reflection sheet 301, and the optical member 401.

  In addition, the display device 500 includes a lighting device 300, a liquid crystal panel 402, and the like.

  A plurality of light emitting elements 200 are mounted on the substrate 210 at a predetermined interval, and are arranged in a staggered pattern on the substrate 210 when viewed in plan.

  A plurality of light flux controlling members 150 are mounted on the substrate 210 so as to cover the light emitting element 200, and are arranged in a staggered pattern on the substrate 210 when viewed in plan.

  The reflection sheet 301 is white, and as shown in FIG. 3, a plurality of through holes 302 having a size through which the light flux controlling member 150 can pass are formed. Further, as many through holes 302 as the number of light flux control members 150 in the reflection sheet 301 are formed at positions corresponding to the light flux control members 150. Further, even if the reflective sheet 301 is a color that easily absorbs light that is not white, such as green or ocher, the reflective sheet 301 can increase the reflectance of light by covering the reflective sheet 301. Note that when the surface of the substrate 210 and the bottom surface of the lighting device on which the substrate 210 is disposed are formed of a highly reflective material, the reflective sheet 301 may not be used.

  The optical member 401 is provided on the back side of the liquid crystal panel 402. Further, the irradiated surface 401 a is irradiated with light emitted from the emission surface 104 of the light flux controlling member 150. The irradiated surface 401a is, for example, the back surface of the diffusion plate. When the display device 500 is a liquid crystal display device, the back side of the liquid crystal panel 402 is irradiated with light emitted from the light emitting surface 401 b of the optical member 401 of the lighting device 300. The optical member 401 is not limited to a liquid crystal display device such as a diffusing plate or a prism sheet, and draws characters, pictures, or the like irradiated from the inside of the lighting device 300 by light emitted from the emission surface 104. Any signboard or other sign may be used.

  The optical member 401 emits illumination light suitable for illuminating the liquid crystal panel 402 as an illuminated member by diffusing or condensing the light emitted from the emission surface 104 incident on the illuminated surface 401a. To do.

  Since the light emitting device 100 has already been described above, the description thereof is omitted.

(Configuration of incident surface of light flux controlling member)
The shape of the incident surface 103 will be described in detail with reference to FIGS. FIG. 5 is an enlarged cross-sectional view of a main part of the light flux controlling member 150. FIG. 6 is an enlarged view of the incident surface 103 of the light flux controlling member 150. FIG. 7 is a diagram showing the relationship between r and θr on the incident surface 103 of the light flux controlling member 150. FIG. 8 is a diagram showing the relationship between Δr / Δθr and θr on the incident surface 103 of the light flux controlling member 150.

  In FIG. 5, the intersection point O is an intersection point between the light emitting surface of the light emitting element 200 that is a light source and the central axis P1. The straight line L is a straight line connecting the intersection point O and any point on the incident surface 103. Further, the angle θr is an angle with respect to the central axis P1 of the straight line L. The distance r is a distance between the intersection point O and an arbitrary point on the incident surface 103. However, the angle θr is an angle smaller than 90 °. In FIG. 5, the vertex T is an intersection of the central axis P <b> 1 and the incident surface 103. In FIG. 5, a point U is a point on the opening end of the incident surface 103.

  In FIG. 6, the origin indicates the intersection point O in FIG. 5, the horizontal axis indicates the distance from the intersection point O on the X axis in FIG. 5, and the vertical axis indicates the distance from the intersection point O on the Y axis in FIG. Indicates. In FIG. 6, the horizontal axis is the angle θr in FIG. 5, and the vertical axis is the distance from the intersection point O on the Y axis in FIG.

  As shown in FIG. 5, the incident surface 103 has a skirt that extends toward the opening edge of the recess 102 in a cross section parallel to the central axis P <b> 1 including the central axis P <b> 1 (hereinafter referred to as “reference cross section”). The curve shape connects two curves (curve 103a in the reference section) (second region) to one curve (curve 103b in the reference section) (first region). In addition, the incident surface 103 has two curved lines (curves 103a and 103a in the reference section) and one curve (reference section) in which the angle θr of the straight line L with respect to the central axis P1 has a predetermined value in the reference section. The curve 103b) in the cross section is a connected curve.

  That is, in the present embodiment, the incident surface 103 of the light flux controlling member 150 intersects the central axis P1 and is formed in a rotationally symmetrical manner with respect to the central axis P1 (curve 103b in the reference cross section), It has the 2nd field 103a (curve 103a in a standard section) connected to this. Specifically, the incident surface 103 has a shape having a first region 103b that is a curve in which the distance r decreases as the angle θr formed by the straight line L and the central axis P1 increases in the reference cross section. In addition, the incident surface 103 is line symmetric with respect to the central axis P1, and connects the point U on the opening edge of the recess 102 and the end point E of the curve 103b in the reference cross section, and the straight line L and the central axis P1 This is a shape having a second region 103a that is a curve in which the distance r increases as the formed angle θr increases. Here, the end point E is a point where the circle S centering on the intersection point O contacts the incident surface 103 in the reference cross section.

  The second region 103a connects the opening edge of the incident surface 103 and the outer edge of the first region 103b. Moreover, the 2nd area | region 103a approaches the outer periphery 110 of the circular shape at the time of planar view, so that it approaches the opening edge. In addition, the incident surface 103 formed by connecting the first region 103b and the second region 103a has an inflection point V at a predetermined position on the first region 103b in the reference cross section. In addition, the angle θr at the connecting portion between the first region 103b and the second region 103a is preferably 50 ° or more, and more preferably 70 ° or more.

  The larger the proportion of the first region 103b in the incident surface 103, the higher the effect of spreading the light. When the range where the angle θr is greater than or equal to 0 ° and less than 50 ° is the first region 103b, about 60% of the total luminous flux emitted from the light source (light emitting element 200) showing the light distribution characteristic of Lambert distribution. Can be incident on the first region 103b. In addition, when the range where the angle θr is 0 ° or more and less than 70 ° is the first region 103b, about 90% of the total luminous flux emitted from the light source (light emitting element 200) showing the light distribution characteristic of Lambert distribution. Can be incident on the first region 103b.

  FIG. 7 shows a case where the distance r decreases when the angle θr is 0 ° or more and less than 70 °, and increases when the angle θr is 70 ° or more and 90 ° or less.

  Further, as shown in FIG. 8, by making the incident surface 103 into the above-described shape, the value of Δr / Δθr is a negative value when the angle θr is from 0 ° to about 15 ° and increases with the increase of the angle θr. The value of Δr / Δθr gradually decreases. Further, the value of Δr / Δθr is a negative value when the angle θr is about 15 ° to about 70 °, and the value of Δr / Δθr gradually increases as the angle θr increases. Further, the value of Δr / Δθr is a positive value when the angle θr is about 70 ° or more, and the value of Δr / Δθr gradually increases as the angle θr increases.

  By making the incident surface 103 into the shape of the curve described above, the incident surface 103 has a bell shape as a whole, and has a shape in which the skirt expands toward the opening end on the opening end side.

(Optical characteristics of the light flux controlling member)
The path of light from after being emitted from the light emitting element 200 to after being incident on the incident surface 103 will be described with reference to FIG. FIG. 9 is a diagram illustrating a light path from after being emitted from the light emitting element 200 according to the present embodiment to being incident on the incident surface 103. 9, the same parts as those in FIG. 5 are denoted by the same reference numerals as those in FIG.

  As shown in FIG. 9, among the light emitted from the light emitting element 200, the light incident on the first region 103b of the incident surface 103 is refracted in a direction in which the angle formed with the central axis P1 on the incident surface 103 increases. Thus, the angle with the straight line parallel to the central axis P1 advances in the direction of θ1.

  Of the light emitted from the light emitting element 200, the light incident on the second region 103a of the incident surface 103 is refracted in a direction in which the angle formed with the central axis P1 on the incident surface 103 decreases, and the central axis P1 The angle with the straight line parallel to is advanced in the direction of θ2.

  Further, the incident surface 103 is formed with a region in which the traveling direction θ2 of the light emitted from the second region 103a gradually decreases as the angle θr increases by making the second region 103a a curved surface with an expanded skirt. The Therefore, in this embodiment, it is conceivable that the diffusibility is reduced as compared with the case where the incident surface 103 is formed only by the first region 103b. However, in this embodiment, the first region 103b and the second region 103a are connected at a predetermined angle at which the angle θr does not cause an extreme decrease in diffusivity, thereby suppressing the decrease in diffusivity. Can do. In other words, the improvement in diffusibility generally depends on light incident on a region where the angle θr of the incident surface 103 is between 0 ° and a predetermined angle. Therefore, even if the incident surface 103 is formed so that the skirts in FIG. 5 are widened (curves 103a and 103a in the reference cross section) in the range where the angle θr is equal to or larger than a predetermined angle, a decrease in diffusibility is suppressed. be able to. Here, the angle for minimizing the decrease in diffusibility is preferably 50 ° (θr = 50 °) or more, and more preferably 70 ° (θr = 70 °) or more. Thereby, at least 60% or more of the total luminous flux of the light emitted from the light emitting element 200 is incident on the first region 103b, and the diffusibility of the luminous flux control member 150 can be maintained.

(Effect of this embodiment)
Thus, in this Embodiment, the incident surface made into the bell shape in order to improve a diffusibility is made into the shape which the skirt spreads further toward the opening edge. Thus, according to the present embodiment, it is possible to arrange the light emitting element at a predetermined position without interfering with the light flux controlling member without downsizing the light emitting element, thereby achieving both improvement in light diffusibility and downsizing. Can be planned.

  Further, according to the present embodiment, since the light emitting element is not downsized, a predetermined amount of light can be secured in the light emitted from the light emitting element.

  In addition, according to the present embodiment, the shape of the hem is widened from the position on the incident surface where the angle with respect to the central axis of the straight line connecting the light source and the predetermined point on the incident surface is 50 ° or more toward the opening edge. Therefore, the light flux controlling member can be downsized while ensuring good light diffusibility.

  Further, according to the present embodiment, even when the light flux controlling member is downsized, a high-quality lighting device with a light emitting surface can be obtained without producing a specific bright portion directly above the light emitting element. .

(Modification of this embodiment)
In the present embodiment, the second region 103a of the incident surface 103 is formed in a curve that spreads in the reference section, but the present invention is not limited to this, and the second region 103a of the incident surface 103 is formed in the reference section. You may form in the straight line of an extension.

  The present invention particularly relates to a light emitting device that emits light emitted from a light source while controlling the light distribution of the incident light, an illuminating device that uses the illuminating device, and an illumination device that uses the illuminating device. It is suitable for a display device used in combination with an illuminated member.

P1 central axis 101 bottom surface 102 recess 103 incident surface 103a second region 103b first region 200 light emitting element L straight line O intersection r distance U point on opening edge V inflection point θr angle

Claims (5)

A light source mounted on a substrate and a central axis that is concentric with the optical axis of the light source are arranged so that the light emitted from the light source is incident and the light distribution of the incident light is controlled and emitted. A light-emitting device having a light flux controlling member,
The light flux controlling member is
The bottom,
A concave portion formed by recessing a part of the bottom surface and opening in the bottom surface;
An inner surface of the recess and an incident surface on which light emitted from the light source is incident;
An exit surface that is disposed on the opposite side of the bottom surface and controls the light distribution of light incident from the entrance surface to emit light to the outside;
Have
The incident surface is
In a cross-section parallel to the central axis including the central axis, the line is symmetrical with respect to the central axis, and an arbitrary point on the incident surface when the intersection of the central axis and the light emitting surface of the light source is used as a reference point The first curve is a first curve in which the distance r between an arbitrary point on the incident surface and the reference point decreases as the angle θr formed by a straight line connecting the point and the reference point and the central axis increases. One area ,
In the cross section, the line is symmetrical with respect to the central axis, connects the point on the opening edge of the recess and the end point of the first curve, and the distance r increases as the angle θr increases. A second region that is a second curve or straight line;
Shape der consisting is,
The end of the second region opposite to the first region is located at the opening edge of the recess formed in the bottom surface,
Both the light incident on the first region and the light incident on the second region are emitted from the emission surface.
Light emitting device. The incident surface includes the first region which is the first curve in which the distance r decreases as the angle θr increases when the angle θr is 0 ° or more and less than 50 °, and the angle θr is 50 ° or more and 90 °. with increasing in the following, the distance r is a shape that is composed of said second curve or the a straight line and the second region increases, the light-emitting device according to claim 1. The incident surface includes the first region which is the first curve in which the distance r decreases as the angle θr increases when the angle θr is 0 ° or more and less than 70 °, and the angle θr is 70 ° or more and 90 °. with increasing in the following, the distance r is a shape that is composed of said second curve or the a straight line and the second region increases, the light-emitting device according to claim 1. A light emitting device according to claim 1;
An illuminated surface illuminated by light emitted from the exit surface of the light emitting device ;
The a lighting device. A lighting device according to claim 4;
A member to be illuminated illuminated by light emitted from the illumination device ;
A has a display device.

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