JP7186359B2 - Light-emitting device and light-emitting circuit - Google Patents

Description

Embodiments relate to light-emitting devices and light-emitting circuits.

Conventionally, lighting devices capable of changing the color temperature of illumination light have been developed. In recent years, there has also been a demand for a lighting device capable of switching the light distribution angle. For example, one lighting device is required to illuminate an entire room with a large light distribution angle in some situations, and to illuminate a narrow area with a small light distribution angle in other situations. As means for realizing such a lighting device, it is conceivable to provide a plurality of types of light emitting elements in one lighting device and change the positional relationship between the light emitting elements and the optical system by mechanical means. However, a lighting device provided with such a mechanical means is large-sized, expensive, takes time to switch, and furthermore, has a problem of degrading interior design.

Japanese Patent Application Laid-Open No. 2007-335101

Embodiments have been made in view of the above problems, and provide a light emitting device and a light emitting circuit that are capable of changing the color temperature and switching the light distribution angle without using mechanical means. With the goal.

A light emitting device according to an embodiment includes one or more first light emitting elements arranged in a first region, one or more second light emitting elements arranged in a second region surrounding the first region, and an optical member. , provided. The optical member includes a first light collecting portion that collects light incident from the first region, and a first light collecting portion that is disposed around the first light collecting portion and guides light that has entered from the second region. and a light guide. A color temperature of light emitted from the second light emitting element is different from a color temperature of light emitted from the first light emitting element. A first circuit including the one or more first light emitting elements and a second circuit including the one or more second light emitting elements are connected in parallel to each other, and the first circuit connected in series in the first circuit The number of stages of light emitting elements is smaller than the number of stages of the second light emitting elements connected in series in the second circuit.

A light emitting circuit according to an embodiment includes one or more first light emitting elements arranged in a first region, and one or more second light emitting elements arranged in a second region surrounding the first region. A color temperature of light emitted from the second light emitting element is different from a color temperature of light emitted from the first light emitting element. A first circuit including the one or more first light emitting elements and a second circuit including the one or more second light emitting elements are connected in parallel to each other, and the first circuit connected in series in the first circuit The number of stages of light emitting elements is smaller than the number of stages of the second light emitting elements connected in series in the second circuit.

According to the embodiments, it is possible to realize a light-emitting device and a light-emitting circuit capable of changing the color temperature and switching the light distribution angle without using mechanical means.

1 is an exploded perspective end view showing a lighting device according to a first embodiment; FIG. It is an end elevation showing the lighting installation concerning a 1st embodiment. BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows the illuminating device which concerns on 1st Embodiment. It is a top view which shows the light source part of 1st Embodiment. 1 is a circuit diagram showing a light emitting circuit according to a first embodiment; FIG. 1 is a perspective end view showing an optical member according to a first embodiment; FIG. It is an end view showing the optical member according to the first embodiment. FIG. 2 is a plan view of the optical member according to the first embodiment, viewed from the direction of light incidence; FIG. 2 is a plan view of the optical member according to the first embodiment, viewed from the light emitting direction; 1 is a perspective view showing an optical member according to a first embodiment; FIG. 4 is a graph showing the behavior of the first light emitting element and the second light emitting element of the first embodiment, with the horizontal axis representing the input current and the vertical axis representing the luminous flux. 4 is a graph showing the behavior of the light emitting device according to the first embodiment, with the horizontal axis representing the input current and the vertical axis representing the color temperature. FIG. 10 is a diagram showing a simulation result of the trajectory of light emitted from the first light emitting element; FIG. 10 is a diagram showing a simulation result of the trajectory of light emitted from the second light emitting element; FIG. 5 is an end view showing the positional relationship between the trajectory of light emitted from the diffusion plate and the cover member; It is a top view which shows the light source part of 2nd Embodiment. FIG. 5 is a circuit diagram showing a light emitting circuit according to a second embodiment; It is a chromaticity coordinate diagram showing changes in color of light emitted from a light emitting device, with x on the horizontal axis and y on the vertical axis. It is a top view which shows the light source part of 3rd Embodiment. It is a top view which shows the light source part of 4th Embodiment. It is an end elevation which shows the optical member of 4th Embodiment. It is a figure which shows the dimension of the 1st light guide part and the 2nd light guide part in an Example. 5 is a graph showing a simulation result of the distribution of light emitted from the first light guide part of the example, with the horizontal axis representing the angle from the center and the vertical axis representing the luminous intensity. 7 is a graph showing a simulation result of the distribution of light emitted from the second light guide section of the example, with the horizontal axis representing the angle from the center and the vertical axis representing the luminous intensity.

<First embodiment>
First, the first embodiment will be described.
FIG. 1 is an exploded perspective end view showing a lighting device according to this embodiment.
FIG. 2A is an end view showing the lighting device according to this embodiment.
FIG. 2B is a perspective view showing the lighting device according to this embodiment.
FIG. 3 is a plan view showing the light source section of this embodiment.
FIG. 4 is a circuit diagram showing a light emitting circuit according to this embodiment.

First, the configuration of the illumination device 90 according to this embodiment will be schematically described. The illumination device 90 includes a light source section 10 , an optical member 20 , a diffusion plate 30 and a cover member 40 . A light emitting device 1 is configured by the light source section 10 and the optical member 20 . The light source section 10 has a light emitting circuit 81 .

The light emitting circuit 81 has one or more first light emitting elements 11 arranged in the first region 51 and one or more second light emitting elements 12 arranged in the second region 52 . The second area 52 is arranged around the first area 51 . The color temperature of light emitted from the second light emitting element 12 is different from the color temperature of light emitted from the first light emitting element 11 . In the light emitting circuit 81, a first circuit 61 including one or more first light emitting elements 11 and a second circuit 62 including one or more second light emitting elements 12 are connected in parallel. The number of stages of the first light emitting elements 11 connected in series in the first circuit 61 is smaller than the number of stages of the second light emitting elements 12 connected in series in the second circuit 62 .

The optical member 20 has a first condensing section 22 , a second condensing section 23 and a first light guiding section 24 . The first condensing part 22 condenses the light incident from the first region 51 . The second light collecting portion 23 is arranged around the first light collecting portion 22 and collects the light that is emitted from the first region 51 and does not enter the first light collecting portion 22 . The first light guide portion 24 is arranged around the second light collecting portion 23, and internally totally reflects the light incident from the second region 52 to guide the light. The half-value angle of the light emitted from the first light guide section 24 is larger than the half-value angle of the light emitted from the first light condensing section 22 .

The diffuser plate 30 is arranged at a position where the light emitted from the light source section 10 and passed through the optical member 20 is incident. The cover member 40 is arranged at a position to cover the side surfaces of the light emitting device 1 and the diffuser plate 30 . The shape of the cover member 40 is substantially cylindrical, and part of the light passing through the diffuser plate 30 is reflected on the inner surface thereof.

A detailed description will be given below.
A single wiring board 19 is provided in the light source unit 10 . The shape of the wiring board 19 is, for example, a substantially disc shape. However, it is not limited to this. The wiring board 19 has wiring provided in a base material made of, for example, a resin material. The first light emitting element 11 and the second light emitting element 12 are mounted on the mounting surface 19 a of the wiring board 19 .

Four first light emitting elements 11 are provided, for example, and are arranged in a first region 51 located near the center of the wiring board 19 . For example, the first region 51 includes the center of the wiring board 19 . For example, seven second light emitting elements 12 are provided and arranged in a circular shape in a second region 52 located around the first region 51 . The first light emitting element 11 and the second light emitting element 12 are, for example, LEDs (Light Emitting Diodes).

The first light emitting element 11 emits light with a color temperature of 2000 K (Kelvin), for example. For example, four first light emitting elements 11 are connected in series with, for example, five resistance elements 71 to 75 via wiring of the wiring board 19 to form the first circuit 61 . In the example shown in FIG. 4, in the first circuit 61, from the positive electrode side to the negative electrode side, the resistance element 71, the first light emitting element 11, the resistance element 72, the resistance element 73, the first light emitting element 11, the resistance element 74, The first light emitting element 11, the resistance element 75, and the first light emitting element 11 are connected in series in this order. That is, in the first circuit 61, the total number of the first light emitting elements 11 is four, and the number of stages of the first light emitting elements 11 connected in series is also four. Each first light emitting element 11 has an anode connected to the positive electrode side and a cathode connected to the negative electrode side.

The second light emitting element 12 emits light with a color temperature of 3000K, for example. The second light emitting elements 12 are connected in series via the wiring of the wiring board 19 to form a second circuit 62 . In the example shown in FIG. 4, in the second circuit 62, for example, seven second light emitting elements 12 are connected in series from the positive electrode side to the negative electrode side without intervening resistance elements. That is, in the second circuit 62, the total number of the second light emitting elements 12 is seven, and the number of stages of the second light emitting elements 12 connected in series is also seven. Each second light emitting element 12 has an anode connected to the positive electrode side and a cathode connected to the negative electrode side.

In the light emitting circuit 81, the positive terminal of the first circuit 61 and the positive terminal of the second circuit 62 are connected to each other, and the negative terminal of the first circuit 61 and the negative terminal of the second circuit 62 are connected to each other. It is connected to the. Thus, the first circuit 61 and the second circuit 62 are connected in parallel between the positive terminal and the negative terminal. In addition, although the example shown in FIGS. 3 and 4 shows an example in which the number of the first light emitting elements 11 is four and the number of the second light emitting elements 12 is seven, the present invention is not limited to this. The first light emitting element 11 is arranged in the first region 51, the second light emitting element 12 is arranged in the second region 52 surrounding the first region 51, and the first light emitting elements 11 connected in series in the first circuit 61 The number of stages should be less than the number of stages of the second light emitting elements 12 connected in series in the second circuit 62 .

FIG. 5A is a perspective end view showing the optical member according to this embodiment.
FIG. 5B is an end view showing the optical member according to this embodiment.
FIG. 6A is a plan view of the optical member according to this embodiment viewed from the direction of light incidence.
FIG. 6B is a plan view of the optical member according to this embodiment viewed from the light emitting direction.
FIG. 6C is a perspective view showing the optical member according to this embodiment.

The optical member 20 is a transparent member integrally formed of a transparent material. The shape of the optical member 20 is generally a body of rotation with the central axis C as the axis of rotation, and has a light entrance surface 21 and a light exit surface 29 . The light incident surface 21 faces the light source section 10 . As will be described later, unevenness is formed on the light incident surface 21 of the optical member 20, and the unevenness realizes an optical function. The light exit surface 29 is a plane orthogonal to the central axis C. As shown in FIG. Hereinafter, among the directions in which the central axis C of the optical member 20 extends, the direction from the light exit surface 29 to the light entrance surface 21 is called the "light entrance direction" , and the direction from the light entrance surface 21 to the light exit surface 29 is called the "light entrance direction". "light emission direction".

A central portion of the light incident surface 21 is provided with a first light condensing portion 22 projecting in the light incident direction. The first condensing section 22 is arranged at a position corresponding to the first region 51 of the light source section 10 , for example, arranged at a position facing the first region 51 . The shape of the first condensing part 22 is a convex lens shape, for example, a part of a spheroid. The outer surface 22a of the first condensing portion 22 is a convex curved surface. The minimum radius of curvature of the outer surface 22a is 0.3 mm or more and 13 mm or less. The minimum radius of curvature of the outer surface 22a can be measured in a cross section including the central axis C, for example.

A second light collecting section 23 is provided around the first light collecting section 22 . The shape of the second condensing part 23 is a substantially truncated cone shape with a recessed top part. The second condensing part 23 faces the area between the first area 51 and the second area 52 in the light source part 10 . The surface of the second condensing portion 23 includes an inner surface 23a, an upper surface 23b, and an outer surface 23c.

The inner surface 23a is in contact with the outer surface 22a of the first condensing portion 22, and is inclined away from the central axis C toward the direction of light incidence. The upper surface 23b is arranged around the inner surface 23a and is in contact with the inner surface 23a. The upper surface 23 b is an annular flat surface parallel to the light exit surface 29 . The outer surface 23c is arranged around the upper surface 23b and is in contact with the upper surface 23b. The outer surface 23c is inclined away from the central axis C toward the direction of light emission. Further, the outer surface 23c is curved outward with respect to the light exit surface 29, that is, convex toward the light incident direction. The minimum radius of curvature of the outer surface 23c is 0.6 mm or more and 28 mm or less. The minimum radius of curvature of the outer surface 23c can also be measured in a cross section containing the central axis C, for example.

A first light guiding portion 24 is provided around the second light condensing portion 23 . The shape of the first light guide portion 24 is a cylinder that surrounds the second light collecting portion 23 in an annular shape. The cross-sectional shape of a plane perpendicular to the light exit surface 29, for example, a plane including the central axis C, of the first light guide portion 24 is trapezoidal. The surface of the first light guide section 24 includes an inner surface 24a, an upper surface 24b, and an outer surface 24c.

The inner surface 24a is in contact with the outer surface 23c of the second condensing portion 23, and is inclined away from the central axis C toward the direction of light incidence. The boundary line 28a between the outer surface 23c of the second light collecting section 23 and the inner surface 24a of the first light guide section 24 is the boundary line 28b between the outer surface 22a of the first light collecting section 22 and the inner surface 23a of the second light collecting section 23. is positioned on the light emitting direction side. That is, the distance between boundary line 28 a and light exit surface 29 is shorter than the distance between boundary line 28 b and light exit surface 29 .

The upper surface 24b is arranged around the inner surface 24a and contacts the inner surface 24a. The upper surface 24 b is a ring-shaped plane parallel to the light exit surface 29 . The upper surface 24 b is arranged at a position corresponding to the second region 52 of the light source unit 10 , for example, arranged at a position facing the second region 52 . The upper surface 23b of the second light collecting section 23 and the upper surface 24b of the first light guide section 24 are positioned on the same plane. The outer surface 24c may be perpendicular to the light exit surface 29, or may be inclined away from the central axis C toward the light exit direction.

A flat plate portion 25 is provided around the first light guide portion 24 . The flat plate portion 25 may have any shape as long as it surrounds the periphery of the first light guide portion 24, and is preferably an annular plate shape. The upper surface 25a of the flat plate portion 25 is a plane parallel to the light exit surface 29 of the optical member 20 and perpendicular to the central axis C. As shown in FIG.

The light incident surface 21 is arranged at a position and angle where the whole can be seen directly from the light emitting direction. That is, the outer surface 22a of the first light collecting portion 22, the inner surface 23a, the upper surface 23b, the outer surface 23c of the second light collecting portion 23, the inner surface 24a, the upper surface 24b, the outer surface 24c of the first light guide portion 24, the upper surface 25a of the flat plate portion 25 are all facing the light exit surface 29 . Therefore, the optical member 20 can be produced by injection molding or the like. For example, the optical member 20 can be molded by pouring a transparent resin into a mold that is open on the light emitting surface 29 side, solidifying it, and pulling it out in the light emitting direction.

The diffusion plate 30 is made of a transparent material such as glass or a resin material, and diffuses and transmits incident light. For example, one or both surfaces of the diffuser plate 30 may have fine unevenness. Alternatively, in the diffusion plate 30, a material having a different refractive index from that of the base material may be dispersed in the base material. The diffusion plate 30 may have any shape as long as it covers the light exit surface 29, and is preferably disk-shaped. The diffusion plate 30 is arranged on the light exit surface 29 side of the optical member 20 and is in contact with the light exit surface 29, for example.

The cover member 40 has a collar portion 41 , a storage portion 42 and a cone portion 43 . The cover member 40 is made of an opaque material such as a white resin material, a dark resin material, or a metal material. The shape of the cover member 40 is generally a rotating body, and the central axis of the cover member 40 substantially coincides with the central axis C of the optical member 20 .

The shape of the collar portion 41 is, for example, an annular plate shape. The collar part 41 is a part for fixing the lighting device 90 to a member to be attached, for example, the ceiling 100 of a room. The storage portion 42 has a cylindrical shape with the entire top surface and the central portion of the bottom surface opened, and stores the light source unit 10 , the optical member 20 , and the diffuser plate 30 inside. The outer peripheral portion of the diffuser plate 30 is sandwiched and fixed between the flat plate portion 25 of the optical member 20 and the bottom surface of the storage portion 42 of the cover member 40 . The shape of the cone portion 43 is a truncated cone shape whose diameter increases with increasing distance from the storage portion 42 . The top and bottom surfaces of the cone portion 43 are open, and the inside of the cone portion 43 communicates with the inside of the storage portion 42 . The inner surface of the cone portion 43 diffusely reflects light when the cover member 40 is made of a white material, and absorbs light when the cover member 40 is made of a dark material.

Next, the operation of the illumination device 90 according to this embodiment will be described.
First, the operation of the light emitting circuit 81 will be described.
FIG. 7A is a graph showing the behavior of the first light emitting element and the second light emitting element of the present embodiment, with the horizontal axis representing the input current and the vertical axis representing the luminous flux.
FIG. 7B is a graph showing the behavior of the light emitting device according to this embodiment, with the horizontal axis representing the input current and the vertical axis representing the color temperature.

As described above, in the light emitting circuit 81 , the number of stages of the first light emitting elements 11 connected in series in the first circuit 61 is smaller than the number of stages of the second light emitting elements 12 connected in series in the second circuit 62 . Therefore, when the DC current applied to the light emitting circuit 81 is continuously increased from zero, the voltage applied between the anode and the cathode of each first light emitting element 11 initially increases to Since the voltage is higher than the voltage applied between the anode and the cathode of the first light emitting element 11, the first light emitting element 11 becomes conductive first. Therefore, a current flows only through the first circuit 61 and hardly any current flows through the second circuit 62 . Therefore, only the first light emitting element 11 emits light, and light with a color temperature of 2000K is emitted. As the input current increases, the luminous flux of the first light emitting element 11 increases until the input current reaches a value _I1 at which the current flowing through the first light emitting element 11 is substantially saturated.

As the DC current applied to the light emitting circuit 81 is increased, the current also begins to flow through the second light emitting element 12 . Thereby, the second light emitting element 12 also emits light. A current value at which the second light emitting element 12 starts to emit light is assumed to be _I2 . In the range of the current value from 0 to _I22 , only the luminous flux changes according to the input current while the color temperature of the light remains constant at 2000K. The current value _I2 is preferably less than or equal to the current value _I1 . When the current value becomes _I2 or higher, the light emitted from the light source unit 10 becomes light in which the light emitted from the first light emitting element 11 and the light emitted from the second light emitting element 12 are mixed, and the color temperature is 2000K and 3000K. A value between Then, as the input current value increases until the input current value reaches the value _I3 at which the current flowing through the second light emitting element 12 saturates, the luminous flux of the first light emitting element 11 remains substantially constant and the second light emitting element 11 12 luminous flux increases. Moreover, since the ratio of the luminous flux of the first light emitting element 11 and the luminous flux of the second light emitting element 12 changes, the color temperature of the light emitted from the light source section 10 also changes. Therefore, in the range of the current value from _I2 to _I3 , as the input current increases, the luminous flux increases and the color temperature of the light increases from 2000K to a predetermined value between 2000K and 3000K. converge. The resistance values of the resistance elements 71 to 75 are set so that the anode-cathode voltage of each first light-emitting element 11 and the anode-cathode voltage of each second light-emitting element 12 become equal when the current value reaches _I3 . is adjusted to

Next, behavior of light emitted from the light source unit 10 will be described.
FIG. 8 is a diagram showing a simulation result of the trajectory of light emitted from the first light emitting element.
FIG. 9 is a diagram showing a simulation result of the trajectory of light emitted from the second light emitting element.
FIG. 10 is an end view showing the positional relationship between the trajectory of light emitted from the diffusion plate and the cover member.

When the first light emitting element 11 is lit in the first region 51 , part of the light emitted from the first light emitting element 11 enters the outer surface 22 a of the first condensing portion 22 of the optical member 20 . The outer surface 22 a is a first light incident area where light enters the first light condensing section 22 . Hereinafter, the light incident on the first light condensing section 22 is referred to as "light L1". The light L<b>1 is condensed by the convex lens-shaped first condensing part 22 and emitted from the light exit surface 29 . The half-value angle _θHW1 of the light L1 emitted from the first light condensing section 22 is, for example, 24°.

The rest of the light emitted from the first light emitting element 11 , that is, the light emitted from the first region 51 and not incident on the first condensing portion 22 enters the inner surface 23 a of the second condensing portion 23 . Hereinafter, the light incident on the second light condensing section 23 will be referred to as "light L2". The light L2 passes through the inside of the second light condensing section 23, is totally reflected at least in part by the outer surface 23c, and is emitted from the light exit surface 29. As shown in FIG. Since the outer surface 23c is curved outward with respect to the light exit surface 29, the light L2 is condensed by being totally reflected by the outer surface 23c.

When the second light emitting element 12 is lit in the second region 52 , most of the light emitted from the second light emitting element 12 enters the upper surface 24 b of the first light guide section 24 of the optical member 20 . The upper surface 24 b is a second light incident area where light enters the first light guide section 24 . Hereinafter, the light incident on the first light guide section 24 is referred to as "light L3". At least part of the light L3 repeats total reflection between the inner surface 24a and the outer surface 24c of the first light guide portion 24, is guided inside the first light guide portion 24, is diffused, and reaches the light exit surface. 29. The half-value angle _θHW2 of the light L3 emitted from the first light guide section 24 is, for example, 68°. The half-value angle θ _HW2 of the light L3 emitted from the first light guide portion 24 of the optical member 20 is larger than the half-value angle θ _HW1 of the light L1 emitted from the first light collecting portion 22 . That is, θ _HW2 > θ _HW1 .

As described above, in the light emitting device 1, when the first light emitting element 11 is turned on, light is emitted from the first region 51, and the light L1 collected by the first light collecting unit 22 and the second light collecting unit Light L<b>2 condensed by the portion 23 is emitted from the light emitting device 1 . Thereby, light with a small half-value angle can be obtained. On the other hand, when the second light emitting element 12 is turned on, light is emitted from the second region 52 and the light L3 diffused by the first light guide section 24 is emitted from the light emitting device 1 . Thereby, light with a large half-value angle can be obtained. In this manner, the light emitting device 1 can change the luminous flux of each light emitting element by adjusting the input current value, thereby controlling the color temperature and the light distribution angle of the emitted light.

Light emitted from the light emitting surface 29 of the optical member 20 is scattered when passing through the diffuser plate 30 . As a result, the user can see the first light-emitting element 11 or the second light-emitting element 12 directly, thereby reducing the "graininess" and reducing the "color unevenness" and "glare" caused by the light emission angle. can do. The light emitted from the diffusion plate 30 enters the cone portion 43 of the cover member 40 . Part of the light emitted from the diffuser plate 30 reaches the inner surface of the cone portion 43 . In particular, light traveling in a direction with an angle of 30° or less with respect to the mounting surface 19 a of the wiring board 19 always reaches the inner surface of the cone portion 43 . The light L4 is emitted from the end of the portion of the diffusion plate 30 exposed in the cone portion 43 at an angle of 30° with respect to the mounting surface 19a, and shows the trajectory of light passing through the central axis of the cone portion 43. ing.

The cone portion 43 is designed such that the light L4 is incident on the inner surface of the cone portion 43 . When the inner surface of cone portion 43 is made of a white material, the light reaching the inner surface of cone portion 43 is irregularly reflected by the inner surface of cone portion 43 and emitted to the outside of illumination device 90 . When the inner surface of cone portion 43 is made of a dark material, the light reaching the inner surface of cone portion 43 is absorbed by the inner surface of cone portion 43 . Another part of the light emitted from the diffusion plate 30 does not reach the inner surface of the cone portion 43 and is directly emitted to the outside of the illumination device 90 .

Next, the effects of this embodiment will be described.
In the light emitting device 1, the color temperature, luminous flux and light distribution angle of emitted light can be controlled by adjusting the input current value. Thereby, the color temperature, the luminous flux and the light distribution angle can be switched only by electrical means without providing mechanical means. Therefore, it is possible to reduce the size and cost of the light emitting device 1 . In addition, since there is no mechanical operation, switching does not take time, no noise is generated, and reliability is high. Furthermore, since the appearance of the lighting device 90 can be made such that it is difficult to know that the light distribution angle can be switched, it can be installed on the ceiling 100 of a room and used as a downlight. can be improved.

In addition, since the illumination range can be continuously changed from narrow-angle illumination to wide-angle illumination using one optical member 20, the cost of the illumination device 90 can be further reduced. As described above, the cost can be further reduced by forming the optical member 20 by injection molding or the like. Further, from the user's point of view, since the position and area of the light emitting region are almost the same between narrow-angle illumination and wide-angle illumination, there is little discontinuity when switching between narrow-angle illumination and wide-angle illumination.

Furthermore, in the illumination device 90, of the light emitted from the diffuser plate 30, the light traveling in a direction with an angle of 30° or less with respect to the mounting surface 19a of the wiring board 19 is emitted from the cone portion when the cover member 40 is made of a white material. When the cover member 40 is made of a dark-colored material, the light is diffusely reflected by the inner surface of the diffusing plate 43 and absorbed by the inner surface of the cone portion 43 , so that the light is not directly emitted from the diffuser plate 30 to the outside of the lighting device 90 . As a result, light emitted from the first light emitting element 11 and the second light emitting element 12 at a shallow angle can be prevented from directly entering the user's eyes, and glare can be suppressed. Further, in the illumination device 90, the light L1 and L2 for narrow-angle illumination and the light L3 for wide-angle illumination can be emitted from one optical member 20, so the light emitting area can be reduced. As a result, the height of the cone portion 43 can be reduced while blocking light of 30° or less, and the lighting device 90 as a whole can be made compact.

Note that the color temperature, the luminous flux, and the light distribution angle may be switched by sensing a person using a sensor. For example, when the room is unoccupied, both the first light emitting element 11 and the second light emitting element 12 are turned off, and when a person appears at the entrance of the room, only the first light emitting element 11 is turned on. Only the vicinity of the entrance is locally illuminated with weak light, and when a person enters the room, both the first light emitting element 11 and the second light emitting element 12 are turned on to brightly illuminate the entire room. may

<Second embodiment>
Next, a second embodiment will be described.
FIG. 11 is a plan view showing the light source section of this embodiment.
FIG. 12 is a circuit diagram showing a light emitting circuit according to this embodiment.
In addition, in the following description, in principle, only differences from the first embodiment will be described. Except for the matters described below, this embodiment is the same as the first embodiment. The same applies to other embodiments described later.

In the light emitting device 2 according to the present embodiment, one or more first light emitting elements 11 are provided in the first area 51 in the light source section 10a, and the first light emitting element 11 and the second light emitting element are provided in the second area 52. One or more elements 12, third light emitting elements 13, and fourth light emitting elements 14 are provided. That is, the first light-emitting element 11 is provided in both the first region 51 and the second region 52, and the second light-emitting device 12, the third light-emitting device 13, and the fourth light-emitting device 14 are provided in the second region 52. provided only for In addition, in FIG. 11, the number of light emitting elements is drawn less than the actual number for the sake of simplification of the drawing. In the example shown in FIG. 12, the total number of first light emitting elements 11, the total number of second light emitting elements 12, the total number of third light emitting elements 13, and the total number of fourth light emitting elements 14 are twelve.

In this embodiment, for example, the color temperature of the light emitted from the first light emitting element 11 is 2700 K, the color temperature of the light emitted from the second light emitting element 12 is 2000 K, and the color temperature of the light emitted from the third light emitting element 13 is 2700 K. The color temperature of the emitted light is 3500K, and the color temperature of the light emitted from the fourth light emitting element 14 is 6500K. The color temperature of the light emitted from each light emitting element is not limited to the above example, and the color temperature of the light emitted from the first light emitting element 11, the color temperature of the light emitted from the second light emitting element 12, the color temperature of the light emitted from the second light emitting element 12, The color temperature of the light emitted from the third light emitting element 13 and the color temperature of the light emitted from the fourth light emitting element 14 should be different from each other.

A light emitting circuit 82 is provided in the light source section 10a. The light emitting circuit 82 includes the first to fourth light emitting elements described above, a plurality of first resistive elements 76 and a plurality of second resistive elements 77 . A first circuit 61 , a second circuit 62 , a third circuit 63 and a fourth circuit 64 are provided in the light emitting circuit 82 . In the light emitting circuit 82, the first circuit 61 and the second circuit 62 are connected in parallel, and the third circuit 63 and the fourth circuit 64 are connected in parallel.

In the first circuit 61, for example, four unit circuits each composed of three first light emitting elements 11 connected in parallel are provided. It is connected to the. Therefore, in the first circuit 61, the total number of the first light emitting elements 11 is 12, and the number of stages of the first light emitting elements 11 connected in series is four. The resistance values of the plurality of first resistance elements 76 may be the same or different.

In the second circuit 62, for example, 12 second light emitting elements 12 are connected in series without intervening resistance elements. Therefore, in the second circuit 62, the total number of the second light emitting elements 12 is twelve, and the number of stages of the second light emitting elements 12 connected in series is also twelve.

In the third circuit 63, for example, four unit circuits each composed of three third light emitting elements 13 connected in parallel are provided. It is connected to the. Therefore, in the third circuit 63, the total number of third light emitting elements 13 is twelve, and the number of stages of the third light emitting elements 13 connected in series is four. The resistance values of the plurality of second resistance elements 77 may be the same or different.

In the fourth circuit 64, for example, 12 fourth light emitting elements 14 are connected in series without intervening resistance elements. Therefore, in the fourth circuit 64, the total number of fourth light emitting elements 14 is twelve, and the number of stages of the fourth light emitting elements 14 connected in series is twelve.

Next, the operation of this embodiment will be described.
Since the first light emitting element 11 is arranged in both the first area 51 and the second area 52, the light emitted from the first light emitting element 11 is directed to the first light collecting portion 22 and the second light collecting portion 22 of the optical member 20. The light is emitted from the light section 23 and the first light guide section 24 . Since the second light emitting element 12, the third light emitting element 13, and the fourth light emitting element 14 are arranged only in the second region 52, light emitted from the second light emitting element 12, the third light emitting element 13, and the fourth light emitting element 14 Light is emitted from the first light guide section 24 .

The first circuit 61 and the second circuit 62 are connected to the same power supply and are applied with the same voltage. As a result, as described in the first embodiment, when the input current value is gradually increased from zero, the first light emitting element 11 begins to emit light first, and the current flowing through the first light emitting element 11 becomes saturated. The second light emitting element 12 begins to emit light from the vicinity of the point where the light is emitted. As a result, when the input current value is changed, the overall color temperature, luminous flux and light distribution angle change according to a predetermined relationship.

The third circuit 63 and the fourth circuit 64 are connected to the same power supply and are applied with the same voltage. As a result, when the input current value is gradually increased from zero, the third light emitting element 13 begins to emit light first, and the fourth light emitting element 14 emits light when the current flowing through the third light emitting element 13 is saturated. Begin to. As a result, changing the input current value causes the overall color temperature and luminous flux to change according to a predetermined relationship.

By controlling the ratio between the value of the current flowing through the first circuit 61 and the second circuit 62 and the value of the current flowing through the third circuit 63 and the fourth circuit 64, the first light emitting element 11 and the second light emitting element 12 , the ratio of the light emitted from the third light emitting element 13 and the fourth light emitting element 14 can be controlled. By optimizing this control, the color of the light emitted from the light emitting device 2 can be varied along with blackbody radiation.

FIG. 13 is a chromaticity coordinate diagram showing changes in the color of light emitted from the light emitting device, with x on the horizontal axis and y on the vertical axis.
The dashed curve in FIG. 13 represents the theoretical curve of the color change of black body radiation, the solid curve represents the simulation result of the color change of the light emitted from the light emitting device according to this embodiment, and the dashed line represents the straight line. represents the color change of light emitted from a light-emitting device using only two types of light-emitting elements.
As shown in FIG. 13, according to this embodiment, the light emitted from the light emitting device 2 can be changed along the black body radiation.

Next, the effects of this embodiment will be described.
According to the present embodiment, since four types of light-emitting elements having mutually different color temperatures are provided, the adjustment range of the color temperature is wider than that of the first embodiment. In addition, the first circuit 61 including the first light emitting element 11 and the second circuit 62 including the second light emitting element 12 are connected in parallel, and the number of stages of the first light emitting elements 11 connected in series in the first circuit 61 is is smaller than the number of stages of the second light emitting elements 12 connected in series in the second circuit 62, the first light emitting element 11 and the second light emitting element 11 and the second light emitting element It is possible to smoothly and continuously transition to a state in which both of the elements 12 emit light. Similarly, a third circuit 63 including the third light emitting element 13 and a fourth circuit 64 including the fourth light emitting element 14 are connected in parallel, and the third circuit 63 connects the third light emitting elements 13 in series. Since the number of stages is made smaller than the number of stages of the fourth light emitting elements 14 connected in series in the fourth circuit 64, the third light emitting element 13 and the fourth It is possible to smoothly and continuously transition to a state in which both of the light emitting elements 14 emit light.

Then, the value of current flowing through the circuit in which the first circuit 61 and the second circuit 62 are connected in parallel and the value of current flowing in the circuit in which the third circuit 63 and the fourth circuit 64 are connected in parallel are controlled appropriately. Thus, it is possible to smoothly and continuously transition from the state in which the first light emitting element 11 alone emits light to the state in which all the light emitting elements emit light. As a result, the color temperature, the luminous flux, and the light distribution angle can be changed continuously, and it is possible to prevent the user from feeling discomfort during dimming. Also, it becomes possible to change the color of the light along the black body radiation. As a result, more natural dimming becomes possible, and the user can feel secure.

<Third Embodiment>
Next, a third embodiment will be described.
FIG. 14 is a plan view showing the light source section of this embodiment.
The light emitting circuit according to this embodiment is similar to the light emitting circuit 82 shown in FIG.

In the light emitting device 3 according to this embodiment, both the first light emitting element 11 and the second light emitting element 12 are provided in the first region 51 in the light source section 10b. A first light emitting element 11 , a second light emitting element 12 , a third light emitting element 13 and a fourth light emitting element 14 are provided in the second region 52 . In addition, in FIG. 14, the number of light emitting elements is drawn less than the actual number for the sake of simplification of the drawing. The same applies to FIGS. 15 and 16 to be described later.

According to the present embodiment, compared with the second embodiment, the light that is emitted from the first light collecting section 22 and the second light collecting section 23 and illuminates the narrow-angle region also passes through the first light emitting element 11 alone. It is possible to continuously change from the light emitting state to the light emitting state of both the first light emitting element 11 and the second light emitting element 12 . The configuration, operation, and effects of this embodiment other than those described above are the same as those of the second embodiment.

<Fourth Embodiment>
Next, a fourth embodiment will be described.
FIG. 15 is a plan view showing the light source section of this embodiment.
FIG. 16 is an end view showing the optical member of this embodiment.

A light source section 10c is provided in the light emitting device 4 according to the present embodiment. One or more first light emitting elements 11 are provided in the first region 51 in the light source section 10c. In the second region 52, one or more first light emitting elements 11, one or more second light emitting elements 12, one or more third light emitting elements 13, and one or more fourth light emitting elements 14 are provided. Also in the third region 53, one or more first light emitting elements 11, one or more second light emitting elements 12, one or more third light emitting elements 13, and one or more fourth light emitting elements 14 are provided. Therefore, three or more of the first light emitting elements 11, and two or more of each of the second light emitting elements 12, the third light emitting elements 13, and the fourth light emitting elements 14 are provided in the entire light source section 10c. The first area 51 is a circular area including the center of the wiring board 19, the second area is an annular area arranged around the first area 51, and the third area 53 is the second area 52. It is an annular area arranged around the perimeter.

In this embodiment, for example, similarly to the second embodiment, the color temperature of the light emitted from the first light emitting element 11 is 2700K, and the color temperature of the light emitted from the second light emitting element 12 is 2000K. , the color temperature of the light emitted from the third light emitting element 13 is 3500K, and the color temperature of the light emitted from the fourth light emitting element 14 is 6500K. However, it is not limited to this, as long as the color temperatures are different from each other.

Further, in the light emitting device 4 , the optical member 20 a further includes a second light guide portion 26 and a flat plate portion 27 that guide light incident from the third region 53 around the second region 52 . The half-value angle of light emitted from the second light guide section 26 is larger than the half-value angle of light emitted from the first light guide section 24 .

The second light guide portion 26 is provided outside the flat plate portion 25 . The second light guide section 26 is a transparent cylindrical member that surrounds the first light guide section 24 in an annular shape. The second light guide section 26 is arranged at a position corresponding to the third region 53 of the light source section 10 c , for example, arranged at a position facing the third region 53 .

The surface of the second light guide section 26 includes an inner surface 26a, an upper surface 26b, and an outer surface 26c. The inner surface 26a is in contact with the upper surface 25a of the flat plate portion 25 and is parallel to the central axis C, for example. The upper surface 26b is arranged around the inner surface 26a and contacts the inner surface 26a. The upper surface 26 b is an annular plane parallel to the light exit surface 29 and faces the third region 53 . The upper surface 26b is positioned on the same plane as the upper surface 23b of the second light condensing section 23 and the upper surface 24b of the first light guide section 24 . The outer surface 26c contacts the upper surface 26b and is parallel to the central axis C, for example. The second light guide portion 26 has a rectangular cross-sectional shape on a plane perpendicular to the light exit surface 29, for example, a plane including the central axis C. As shown in FIG. Note that the cross-sectional shape of the second light guide portion 26 may be a trapezoid other than a rectangle.

The taper angles of the inner surface 26 a and the outer surface 26 c of the second light guide section 26 , that is, the angle with the central axis C, are smaller than the taper angles of the inner surface 24 a and the outer surface 24 c of the first light guide section 24 . Therefore, the taper ratio of the second light guide section 26 is smaller than the taper ratio of the first light guide section 24 . The “taper ratio” of the light guide portion is defined by the width of the end surface of the light guide portion on the light incident surface 21 side as Win, the width of the end surface on the light exit surface 29 side as Wout, and the taper ratio along the central axis C of the light guide portion. It is a value defined by (Wout-Win)/H, where H is the length of the data. The end surface of the first light guide portion 24 on the light incident surface 21 side is the upper surface 24b, and the end surface on the light exit surface 29 side is a plane connecting the boundary line 28a and the upper surface 25a of the flat plate portion 25. The end face of 26 on the light incident surface 21 side is a top surface 26 b , and the end face on the light exit surface 29 side is a plane connecting the top surface 25 a of the flat plate portion 25 and the top surface 27 a of the flat plate portion 27 . For example, the taper ratio of the first light guide section 24 is greater than 0 and less than or equal to 0.54, and the taper ratio of the second light guide section 26 is greater than or equal to 0 and less than or equal to 0.1. Thereby, the half-value angle of the light emitted from the second light guide section 26 is larger than the half-value angle of the light emitted from the first light guide section 24 .

The flat plate portion 27 is provided outside the second light guide portion 26 . An upper surface 27 a of the flat plate portion 27 is a ring-shaped plane parallel to the light exit surface 29 . The thickness of the flat plate portion 27 is substantially the same as the thickness of the flat plate portion 25, for example. The optical member 20a including the second light guide portion 26 and the flat plate portion 27 is integrally formed of a transparent material.

Next, the operation of the light emitting device according to this embodiment will be described.
When the first light emitting element 11, the second light emitting element 12, the third light emitting element 13, and the fourth light emitting element 14 arranged in the third region 53 are turned on, most of the light emitted from these light emitting elements is emitted from the second light emitting element. The light enters the upper surface 26 b of the light guide section 26 . The upper surface 26 b is a third light incident area where light enters the second light guide section 26 . At least part of the light that has entered the second light guide section 26 from the upper surface 26 b repeats total reflection between the inner surface 26 a and the outer surface 26 c , propagates through the second light guide section 26 , and exits from the light exit surface 29 . The half-value angle θ _HW3 of the light emitted from the second light guide section 26 is larger than the half-value angle θ _HW2 of the light emitted from the first light guide section 24 . That is, θ _HW3 > θ _HW2 > θ _HW1 .

Effects of the present embodiment will be described.
According to this embodiment, as in the second embodiment, four types of light-emitting elements having mutually different color temperatures are provided, so that the color temperature can be controlled in a wide range. In addition, the state in which the first light emitting element 11 alone emits light can be smoothly and continuously changed to the state in which all the light emitting elements emit light. Thereby, the color temperature, the luminous flux and the light distribution angle can be changed continuously. Furthermore, it is also possible to vary the color of the light along the black body radiation.

In addition, since the light emitting element is arranged in the third area 53 of the light source section 10c, and the optical member 20a has the second light guide section 26 for guiding the light incident from the third area 53, the light can be distributed in a wider range. Light angle can be changed. The configuration, operation, and effects of this embodiment other than those described above are the same as those of the second embodiment.

Next, a light emitting device according to an example will be described.
FIG. 17A is a diagram showing the dimensions of the first light guide section 24 and the second light guide section 26 in this embodiment.
FIG. 17B is a graph showing a simulation result of the distribution of light emitted from the first light guide section 24 of the present embodiment, with the horizontal axis representing the angle from the center and the vertical axis representing the luminous intensity.
FIG. 17C is a graph showing a simulation result of the distribution of light emitted from the second light guide section 26 of this embodiment, with the horizontal axis representing the angle from the center and the vertical axis representing the luminous intensity.

For example, the width Win of the end portion of the first light guide portion 24 on the light incident direction side is 3 mm, the width Wout of the end portion on the light output direction side is 6 mm, and the length of the first light guide portion 24 in the light output direction is When H is 10.9 mm, the half-value angle _θHW2 is 68°. On the other hand, the width Win of the end portion of the second light guide portion 26 on the light incident direction side is set to 3 mm, the width Wout of the end portion on the light output direction side is set to 3 mm, and the length of the second light guide portion 26 in the light output direction is When H is 10.9 mm, the half-value angle _θHW3 is 112°. As described above, the half-value angle _θHW1 of the light L1 emitted from the first light condensing section 22 is, for example, 24°. These values are summarized in Table 1 below.

INDUSTRIAL APPLICABILITY The present invention can be used, for example, in indoor lighting devices and the like.

1, 2, 3, 4: Light emitting device 10, 10a, 10b, 10c: Light source part 11: First light emitting element 12: Second light emitting element 13: Third light emitting element 14: Fourth light emitting element 19: Wiring board 19a: Mounting surface 20, 20a: Optical member 21: Light incident surface 22: First light condensing part 22a: Outer surface 23: Second light condensing part 23a: Inner surface 23b: Upper surface 23c: Outer surface 24: First light guide part 24a: Inner surface 24b : upper surface 24c: outer surface 25: flat plate portion 25a: upper surface 26: second light guide portion 26a: inner surface 26b: upper surface 26c: outer surface 27: flat plate portion 27a: upper surface 28a, 28b: boundary line 29: light exit surface 30: diffusion plate 40: cover member 41: collar portion 42: storage portion 43: cone portion 51: first region 52: second region 53: third region 61: first circuit 62: second circuit 63: third circuit 64: fourth Circuits 71, 72, 73, 74, 75: Resistive Element 76: First Resistive Element 77: Second Resistive Element 81, 82: Light Emitting Circuit 90: Lighting Device 100: Ceiling C: Central Axis H: Length I ₁ , I _{2, I3} : current value L1, L2, L3, L4: light Win, Wout: width _θHW1 , _θHW2 , _θHW3 : half-value angle

Claims (14)

one or more first light emitting elements arranged in the first region;
one or more second light emitting elements arranged in a second region around the first region;
one or more third light emitting elements arranged in the second region;
one or more fourth light emitting elements arranged in the second region;
an optical member;
with
The optical member is
a first light condensing part for condensing the light incident from the first region;
a first light guiding section arranged around the first light collecting section and guiding the light incident from the second region;
has
color temperature of light emitted from the first light emitting element, color temperature of light emitted from the second light emitting element, color temperature of light emitted from the third light emitting element, and light emitted from the fourth light emitting element are different from each other,
A first circuit including the one or more first light emitting elements and a second circuit including the one or more second light emitting elements are connected in parallel to each other, and the first circuit connected in series in the first circuit The light-emitting device, wherein the number of stages of light-emitting elements is smaller than the number of stages of the second light-emitting elements connected in series in the second circuit. one or more first light emitting elements arranged in the first region;
one or more second light emitting elements arranged in a second region around the first region;
an optical member;
with
The optical member is
a first light condensing part for condensing the light incident from the first region;
a second light collecting portion disposed around the first light collecting portion for collecting light emitted from the first region and not incident on the first light collecting portion;
a first light guiding section disposed around the second light collecting section and guiding the incident light from the second region by total internal reflection;
has
a half-value angle of light emitted from the first light guide section is larger than a half-value angle of light emitted from the first light collecting section;
The color temperature of the light emitted from the second light emitting element is different from the color temperature of the light emitted from the first light emitting element,
A first circuit including the one or more first light emitting elements and a second circuit including the one or more second light emitting elements are connected in parallel to each other, and the first circuit connected in series in the first circuit The light-emitting device, wherein the number of stages of light-emitting elements is smaller than the number of stages of the second light-emitting elements connected in series in the second circuit. The second condensing part is arranged around the first condensing part, the second condensing part has an inner surface and an outer surface, the outer surface being curved outward with respect to the light emitting surface. 3. The light emitting device according to claim 2. The light emitting device according to claim 2 or 3 , wherein the first light guide section is a cylindrical member that annularly surrounds the first light collecting section. Two or more of the first light emitting elements are provided,
The light-emitting device according to any one of claims 1 to 4, wherein the first light-emitting element is also arranged in the second region. 6. The light emitting device according to claim 1, further comprising a first resistance element connected in series with said first light emitting element in said first circuit. one or more third light emitting elements arranged in the second region;
one or more fourth light emitting elements arranged in the second region;
further comprising
color temperature of light emitted from the first light emitting element, color temperature of light emitted from the second light emitting element, color temperature of light emitted from the third light emitting element, and light emitted from the fourth light emitting element The light emitting device according to any one of claims 2 to 4 , wherein the color temperatures of are different from each other. A third circuit including the one or more third light emitting elements and a fourth circuit including the one or more fourth light emitting elements are connected in parallel to each other, and the third circuit connected in series in the third circuit 8. The light emitting device according to claim 7, wherein the number of stages of light emitting elements is smaller than the number of stages of said fourth light emitting elements connected in series in said fourth circuit. 9. The light emitting device according to claim 8, further comprising a second resistance element connected in series with said third light emitting element in said third circuit. The optical member further has a second light guide section that guides light incident from a third region around the second region,
The half-value angle of the light emitted from the second light guide section is larger than the half-value angle of the light emitted from the first light guide section,
Two or more of the third light emitting element and the fourth light emitting element are provided,
10. The light-emitting device according to claim 7, wherein said third light-emitting element and said fourth light-emitting element are also arranged in said third region. 11. The light emitting device according to any one of claims 7 to 10, wherein the color of light emitted from said optical member can be changed according to blackbody radiation. The light emitting device according to any one of claims 1 to 11, wherein the optical member is integrally formed of a transparent material. one or more first light emitting elements arranged in the first region;
one or more second light emitting elements arranged in a second region around the first region;
one or more third light emitting elements;
one or more fourth light emitting elements;
with
color temperature of light emitted from the first light emitting element, color temperature of light emitted from the second light emitting element, color temperature of light emitted from the third light emitting element, and light emitted from the fourth light emitting element are different from each other,
A first circuit including the one or more first light emitting elements and a second circuit including the one or more second light emitting elements are connected in parallel to each other, and the first circuit connected in series in the first circuit the number of stages of the light emitting elements is less than the number of stages of the second light emitting elements connected in series in the second circuit;
A third circuit including the one or more third light emitting elements and a fourth circuit including the one or more fourth light emitting elements are connected in parallel to each other, and the third circuit connected in series in the third circuit A light emitting circuit in which the number of stages of light emitting elements is smaller than the number of stages of the fourth light emitting elements connected in series in the fourth circuit . 14. The light emitting circuit according to claim 13, further comprising a first resistive element connected in series with said first light emitting element in said first circuit.

Images