JP2011171086A5

JP2011171086A5 -

Info

Publication number: JP2011171086A5
Application number: JP2010033032A
Authority: JP
Filing date: 2010-02-18
Publication date: 2013-01-31
Anticipated expiration: 2030-02-18

Description

かかる発明によれば、白色光源の前方に配置されるレンズシートは、隣接するプリズムとは焦点距離が互いに異なる焦点距離のプリズムを含んでいる。ところで、複数のプリズムの各々に入射した光は、各プリズムの焦点距離に応じた角度で光軸に対して傾いて前方に導かれる。したがって、焦点距離が互い異なるプリズムに入射した光の各々は、互いに交差（混合）するように前方に進行する。このため、発光素子と蛍光体とからなる擬似白色光源から出射された色むらを有する光を同レンズシートに入射させた場合には、各プリズムの焦点距離の大きさに応じて混色（平均化）され、この結果、色むらが低減された照明光を得ることができる。 According to the invention, a lens sheet disposed in front of the white light source, an adjacent prism includes a prism focal different focal lengths from each other distances. By the way, the light incident on each of the plurality of prisms is guided forward at an angle with respect to the optical axis at an angle corresponding to the focal length of each prism. Therefore, each of the lights incident on the prisms having different focal lengths travels forward so as to cross (mix) each other. Therefore, when light with uneven color emitted from a pseudo-white light source composed of a light emitting element and a phosphor is incident on the lens sheet, color mixing (averaging) is performed according to the focal length of each prism. As a result, illumination light with reduced color unevenness can be obtained.

この場合、前記レンズシートは、前記複数のプリズムの少なくとも一部のプリズムが、前記光軸からの距離に応じて焦点距離が変化する領域を含むように形成されていてもよい。 In this case, the lens sheet, at least a portion of the prism of the plurality of prisms may be formed to include a region in which the focal length varies depending on the distance from the optical axis.

このように、所定の領域に存在する複数のプリズムの焦点距離を、光軸からの距離に応じて変化させることにより、色むらの低減効果が有効に発揮されるとともに、レンズシートの設計および作製が容易になる。 As described above, by changing the focal lengths of a plurality of prisms existing in a predetermined region according to the distance from the optical axis, the effect of reducing color unevenness is effectively exhibited, and the design and production of the lens sheet Becomes easier.

また、この場合、光軸寄りの領域に、屈折作用を有する複数の屈折プリズムが、前記光軸から離れるほど焦点距離が大きくなるように形成されているのが好ましい。
かかる発明によれば、光軸寄りの領域である中心部に形成された屈折作用を有する複数の屈折プリズムに入射した光は、入射した位置に応じて光軸に対して様々な角度で外周側に傾く（複数の屈折プリズムの各々が中心部において外周側に位置するほど光軸に対する傾き角が大きくなる）ようにして進行する。これにより、中心部から出射した光と中心部の外周側（中心部よりも外周側）の領域である外周部から出射した光とが互いに混合され、色むらの低減効果がより一層有効に発揮される。また、後述する理由により（段落００４７）、より一層高効率な照明光を得ることができる。 In this case, in a region of an optical axis toward a plurality of refraction prism having a refraction effect, preferably the nearly as focal length away from the optical axis is formed to be larger.
According to this invention, light incident on a plurality of refractive prisms having a refracting action formed in the central portion that is a region near the optical axis is incident on the outer peripheral side at various angles with respect to the optical axis according to the incident position. (Inclination angle with respect to the optical axis increases as each of the plurality of refractive prisms is located on the outer peripheral side in the center). As a result, the light emitted from the central portion and the light emitted from the outer peripheral portion, which is a region on the outer peripheral side (outside of the central portion) of the central portion, are mixed with each other, and the effect of reducing color unevenness is more effectively exhibited. Is done. Further, for the reason described later (paragraph 0047), it is possible to obtain much more efficient illumination light.

また、前記複数の屈折プリズムが形成される領域の外周側の領域に、反射作用を有する複数の反射プリズムが形成されていてもよい。
この場合、前記複数の反射プリズムは、前記光軸に近づくほど焦点距離が大きくなるように形成されていてもよいし、前記光軸からの距離に関係なく焦点距離がランダムに変化するように形成されていてもよい。
かかる発明によれば、レンズシートは、中心部（光軸寄りの領域）に屈折プリズムが形成され、外周部（中心部の外周側）に反射作用を有する複数の反射プリズムが形成されている。このため、従来技術で説明したように、高効率で強度の均一性に優れた出射光を得ることができるとともに、色むらの低減効果がより一層有効に発揮される。
また、前記レンズシートは、前記複数のプリズムの少なくとも一部のプリズムが、前記光軸からの距離に関係なく焦点距離がランダムに変化するように形成された領域を含んでいてもよい。
また、前記レンズシートは、前記複数のプリズムの全てが、光軸からの距離に応じた領域ごとの態様で焦点距離が変化するように形成されていてもよい。

A plurality of reflecting prisms having a reflecting action may be formed in a region on the outer peripheral side of the region where the plurality of refractive prisms are formed.
In this case, the plurality of reflecting prisms may be formed such that the focal length increases as the distance from the optical axis becomes closer, or the focal length changes randomly regardless of the distance from the optical axis. May be .
According to this invention, the lens sheet has a refractive prism formed in the center (region near the optical axis) and a plurality of reflecting prisms having a reflecting action on the outer periphery (outside of the center). For this reason, as described in the prior art, it is possible to obtain outgoing light with high efficiency and excellent intensity uniformity, and the effect of reducing color unevenness is more effectively exhibited.
In addition, the lens sheet may include a region in which at least some of the plurality of prisms are formed such that the focal length changes randomly regardless of the distance from the optical axis.
Further, the lens sheet may be formed such that the focal length of all the plurality of prisms changes in a mode for each region corresponding to the distance from the optical axis.

Claims

A light source that emits white light radially toward the front;
A lens sheet that is arranged in front of the light source and has a plurality of concentric prisms centered on the optical axis and controls the orientation of the white light emitted from the light source.
The light source includes a light emitting element that emits light of a predetermined wavelength, a sealing body that covers the light emitting element in which a phosphor that emits fluorescence in response to the light of the predetermined wavelength emitted from the light emitting element is dispersed, Have
The illumination device according to claim 1, wherein the lens sheet includes the prism having a focal length different from that of the adjacent prism.

2. The illumination device according to claim 1, wherein the lens sheet includes a region in which at least some of the plurality of prisms are formed such that a focal length changes according to a distance from the optical axis.

In a region of an optical axis toward a plurality of refraction prism having a refraction effect, the lighting device according to claim 2, nearly as focal distance away from the optical axis is formed to be larger.

The lighting device according to claim 3 , wherein a plurality of reflecting prisms having a reflecting action are formed in a region on an outer peripheral side of a region where the plurality of refractive prisms are formed .

The illuminating device according to claim 4 , wherein the plurality of reflecting prisms are formed such that a focal distance increases as the optical axis approaches the optical axis .

5. The illumination device according to claim 4 , wherein the plurality of reflecting prisms are formed such that a focal length randomly changes regardless of a distance from the optical axis .

2. The illumination device according to claim 1 , wherein the lens sheet includes a region in which at least some of the plurality of prisms are formed such that a focal length changes randomly regardless of a distance from the optical axis .

2. The illumination device according to claim 1 , wherein the lens sheet is formed such that a focal length of each of the plurality of prisms is changed in a mode for each region according to a distance from the optical axis .

The illumination device according to any one of claims 1 to 8 , wherein the lens sheet includes a prism in which a flat surface is formed between adjacent prisms among the plurality of prisms.

The light source includes a blue light emitting diode that emits blue light, according to any one of claims 1, which is constituted by a phosphor that converts by receiving blue light to yellow light 9 Lighting equipment.