JP2013061399A - Optical element, and illumination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical element capable of emitting light in a linear fashion extending in a longitudinal direction like a filament of an incandescent lamp when observed from a side direction, and taking a slim shape extending in an optical axis direction not a lateral direction; and an illumination device thereof.SOLUTION: The optical element 2 includes: an incident surface 3 on which light is incident; a first region 4 which is projected in a conical shape and refracts light into a downward direction to emit it; a second region 5 which is arranged more outside than the incident surface 3, and reflects light into an upward direction in almost parallel to the optical axis; a third region 6 formed by repeatedly and step-wisely connecting, in a plane 12 almost parallel to the optical axis, a plurality of total reflection surfaces 11 which totally reflect light which is upwardly reflected by the second region 5; and a fourth region 7 and fifth region 8 which have surfaces almost parallel to the optical axis.

Description

  The present invention relates to an optical element and a lighting device.

  FIG. 1 is a diagram illustrating a configuration of a lighting device described in Patent Document 1. As illustrated in FIG. Referring to FIG. 1, the illumination device includes a surface light source 101 and an optical element 103, and the optical element 103 passes through the center of a circle of the circular surface light source 101 and is perpendicular to the surface of the surface light source 101. It has a shape that is infinitely rotationally symmetric with respect to the axis (optical axis).

  More specifically, the optical element 103 includes an incident surface 203 that faces the light emitting surface of the surface light source 101, a first exit surface 205 that faces the entrance surface 203, the entrance surface 203, and the first exit surface 205. The first emission surface 205 is recessed near the optical axis as compared to the peripheral edge (it is depressed at the depth E1 of the depression).

  In such a configuration, as shown in FIG. 2, the light emitted from the surface light source 101 is refracted by the incident surface 203, totally reflected by the first exit surface 205, and refracted by the second exit surface 207. Light in a straight direction can be diffused laterally.

Japanese Patent No. 4660645

  As described above, in the illumination device using the surface light source of Patent Document 1, light in the straight traveling direction can be diffused in the lateral direction, but as shown in FIG. 2, the light is scattered in an arbitrary direction. The direction of light irradiation is not uniform (Problem 1), and the depth E1 of the depression near the optical axis is shallow, so the length of light irradiated in the horizontal direction (the length of the line) ) L1 is very narrow (Problem 2).

  For the reasons described above, the illumination device of Patent Document 1 has a drawback in that it does not emit light linearly in the vertical direction like a filament of an incandescent bulb when observed from the horizontal direction. In addition, in order to diffuse light in the straight traveling direction in the lateral direction, it is necessary to increase the outer diameter of the first exit surface 205, and the longitudinal length of light irradiated in the lateral direction (linear length) ) In order to make L1 longer, the outer diameter of the lens has to be increased, and the illumination device incorporating the lens has a drawback that it has a structure that spreads widely in the lateral direction.

  The present invention, when observed from the lateral direction, can emit light linearly in the vertical direction like a filament of an incandescent bulb, and can take a slim shape extending in the optical axis direction instead of the lateral direction. It is an object to provide possible optical elements and illumination devices.

  In order to achieve the above-mentioned object, the invention according to claim 1 is provided with an incident surface on which light is incident and an opposite surface to the incident surface, and totally reflects at least a part of the light incident on a certain surface. And a first region projecting in a conical shape that is refracted and emitted downward from the opposite side surface, and is positioned outside the incident surface, and light incident from the incident surface is substantially parallel to the optical axis. A second region that reflects upward and a plurality of total reflection surfaces that totally reflect light reflected upward by the second region substantially parallel to the optical axis in a direction substantially perpendicular to the optical axis. A third region that is repeatedly joined in a step-like manner on a surface substantially parallel to the optical axis, and a surface that is substantially parallel to the optical axis that refracts light emitted from the first region in a downward direction. , A fourth region that connects the first region and the third region, and light emitted from the first region. And has a surface substantially parallel to the optical axis so that the light emitted from the third region is emitted in a direction substantially perpendicular to the optical axis, and is emitted from the third region. An optical element comprising a fifth region connecting the three regions.

The invention according to claim 2 is an illumination device including a light source and an optical element,
The optical element is provided on an incident surface facing the light emitting surface of the light source, and on the side opposed to the incident surface by totally reflecting at least a part of light incident on a certain surface. A first region projecting in a cone shape that is refracted and emitted from the surface in a downward direction, and is positioned outward from the incident surface, and light incident from the incident surface is directed upward substantially parallel to the optical axis. And a plurality of total reflection surfaces that totally reflect light reflected upward by the second region in a direction substantially parallel to the optical axis in a direction substantially perpendicular to the optical axis. A third region repeatedly connected in a staircase pattern on substantially parallel surfaces, and a surface substantially parallel to an optical axis that refracts light emitted from the first region in a downward direction; A fourth region connecting the third region and the third region, and the outgoing light from the first region is directed downward A surface that is substantially parallel to the optical axis so that the light emitted from the third region is emitted in a direction substantially perpendicular to the optical axis, and the second region and the third region are emitted. And a fifth region connecting the regions.

  According to the first and second aspects of the present invention, the incident surface on which light is incident and the light incident surface are provided so as to face each other, and at least a part of the light incident on a certain surface is totally reflected to face each other. A first region projecting in a conical shape that is refracted and emitted from the surface on the light-receiving side, and the light incident from the incident surface is positioned substantially parallel to the optical axis and positioned outside the incident surface. A second region that reflects toward the light source, and a plurality of total reflection surfaces that totally reflect light reflected upward by the second region substantially parallel to the optical axis in a direction substantially perpendicular to the optical axis, A third region repeatedly connected in a staircase pattern on a surface substantially parallel to the axis, and a surface substantially parallel to the optical axis that refracts light emitted from the first region in a downward direction, A fourth region connecting the first region and the third region, and the outgoing light from the first region is directed further downward A surface that is substantially parallel to the optical axis so that the light emitted from the third region is emitted in a direction substantially perpendicular to the optical axis, and the second region and the third region are emitted. Since the fifth region is connected to the region, when observed from the lateral direction, it is possible to emit light linearly in the vertical direction like a filament of an incandescent bulb, and light is not the lateral direction. A slim shape extending in the axial direction can be taken. In addition, when observing from below, it is possible to produce a light with a whirling feeling.

It is a figure which shows the structure of the illuminating device described in patent document 1. FIG. It is a figure which shows the light beam path | route of the illuminating device of patent document 1. FIG. It is a figure which shows one structural example of the illuminating device of this invention. It is sectional drawing in the AA of FIG. It is the elements on larger scale which show an example of the 3rd field. It is a figure which shows the light beam path | route of the illuminating device of FIG. 3, FIG. It is the elements on larger scale which show the other example of the 3rd field.

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

  3 and 4 are diagrams showing a configuration example of the illumination device of the present invention. 3 is a perspective view, and FIG. 4 is a cross-sectional view taken along line AA in FIG.

  Referring to FIGS. 3 and 4, the illumination device includes a surface light source 1 and an optical element 2, and the optical element 2 passes through the center of a circle of the circular surface light source 1, for example, and the surface of the surface light source 1. And an infinite rotational symmetry with respect to an axis perpendicular to the optical axis (optical axis).

  That is, the optical element 2 is provided with an incident surface (incident surface on which light is incident) 3 facing the light emitting surface of the surface light source 1 and at least the light incident on a certain surface. A first region 4 projecting in a conical shape that reflects part of the light totally reflected and refracts it from the opposite side and emits it, and is positioned outward of the incident surface 3. The second region (parabolic surface region) 5 that reflects the light incident from the upper side substantially parallel to the optical axis is reflected upward by the second region 5 substantially parallel to the optical axis. A third region 6 in which a plurality of total reflection surfaces 11 that totally reflect light in a substantially horizontal direction (substantially perpendicular to the optical axis) are repeatedly connected in a stepwise manner by a surface 12 substantially parallel to the optical axis; A surface substantially parallel to the optical axis that refracts light emitted from the first region 4 in a downward direction; The fourth region 7 that connects the region 4 and the third region 6, and the emitted light from the first region 4 is refracted in the downward direction and emitted, and the emitted light from the third region 6 A fifth region that has a plane substantially parallel to the optical axis that emits light in a substantially horizontal direction (substantially perpendicular to the optical axis) and connects the second region 5 and the third region 6 8 and.

  Here, a light emitting diode (LED) or the like can be used for the surface light source 1. Moreover, the optical element 2 can be comprised with the light-diffusion lens etc. which consist of a transparent member.

  In FIG. 4, the diameter D0 of the surface light source 1 is, for example, about 4 mm, the outer diameter D2 of the optical element 2 is, for example, about 15 mm, and the height (length in the optical axis direction) H2 of the optical element 2 is, for example, The depression E2 in the optical axis direction of the optical element 2 is, for example, about 10 mm. Further, the total reflection surface 11 of the third region 6 forms an angle of approximately 45 ° with the direction perpendicular to the optical axis.

  FIG. 5 shows an example of the third region 6 as a partially enlarged view. In the example of FIG. 5, the third region 6 has a plurality of total reflection surfaces 11 substantially parallel to the optical axis. The flat surface 12 is connected directly.

  In the illuminating device of FIG. 3 and FIG. 4, the path | route of a light ray can be made as shown in FIG. 6 by the above structures.

  That is, when the light from the surface light source 1 is incident on a surface having the first region 4 projecting conically from the incident surface 3, the light incident on this surface is, as indicated by a broken line in FIG. Totally reflected by this surface of the region 4, refracted in a downward direction from the surface of the first region 4 facing this surface, and then emitted, and then the lens surface of the fourth region 7, the fifth region 8 is sequentially refracted and emitted in the downward direction, so that it is diffused downward (see the ray path Fa in FIGS. 4 and 6). That is, the light from the surface light source 1 can be diffused downward.

  When the light from the surface light source 1 enters the second region (parabolic surface region) 5 from the incident surface 3, the light incident on the second region (parabolic surface region) 5 is changed to the second region (parabolic surface region). The light reflected upward in the paraboloid region (5) substantially parallel to the optical axis and reflected upward in the second region (paraboloid region) 5 substantially parallel to the optical axis is third. Are totally reflected in the substantially horizontal direction (substantially perpendicular to the optical axis) by the plurality of total reflection surfaces 11 in the region 6 and unified in the substantially horizontal direction (substantially perpendicular to the optical axis) from the fifth region 8. It is emitted while maintaining the characteristics. Here, the plurality of total reflection surfaces 11 in the third region 6 are repeatedly joined in a stepped manner by a surface 12 substantially parallel to the optical axis, and the depression E2 in the optical axis direction of the optical element 2 is formed. Since it is deeper, the light emitted from the fifth region 8 in a substantially horizontal direction (substantially perpendicular to the optical axis) while maintaining uniformity is like a filament of an incandescent bulb when observed from the lateral direction. (See the ray path Fb in FIGS. 4 and 6). That is, in the present invention, the length (linear length) L2 in the vertical direction of the light irradiated (emitted) in the horizontal direction (horizontal direction) can be significantly increased as compared with the conventional case. In the present invention, the plurality of total reflection surfaces 11 in the third region 6 are repeatedly connected in a stepped manner by the surface 12 substantially parallel to the optical axis in this case as well. The recess E2 in the optical axis direction 2 becomes deep, and a slim lens shape (optical element shape) extending in the optical axis direction (vertical direction) rather than in the lateral direction is possible.

  As described above, according to the present invention, the light from the surface light source 1 can be diffused downward as in the light beam path Fa of FIGS. 4 and 6, so that the lens (optical element) is observed from below. When it is done, it becomes possible to produce a light with a whispering feeling. Further, according to the present invention, the light emitted from the fifth region 8 in a substantially horizontal direction (in a direction substantially perpendicular to the optical axis) is converted into a lens (like a ray path Fb in FIGS. 4 and 6). When the optical element) is observed from the horizontal direction, it becomes linear in the vertical direction, so that pseudo-linear light emission such as a filament of an incandescent bulb is possible. Also in this case, a slim lens shape (optical element shape) extending in the optical axis direction (vertical direction) instead of the horizontal direction is possible.

  In addition, although such an illuminating device of the present invention can be installed in an arbitrary direction, it is generally installed so that the surface light source 1 and the incident surface 3 side face downward as shown in FIGS. The

  In the above example, as shown in FIG. 5, the third region 6 is formed by directly connecting a plurality of total reflection surfaces 11 with a surface 12 substantially parallel to the optical axis. For convenience in the manufacturing process, a surface 13 that is not substantially parallel to the optical axis is provided between the total reflection surface 11 and the surface 12 that is substantially parallel to the optical axis, as shown in the example of FIG. The reflecting surface 11 may be connected to the surface 12 substantially parallel to the optical axis via a surface 13 that is not substantially parallel to the optical axis, and these cases are also included in the scope of the present invention.

  In the above example, the surface light source 1 has a circular shape and the optical element 2 has an infinitely rotationally symmetric shape (for example, the first region 4 has a conical shape). 1 and the optical element 2 may be polygonal (for example, octagonal) (in this case, the first region 4 is pyramidal), and this case is also included in the scope of the present invention. It is.

  In the above example, the light source 1 is a surface light source. However, in the present invention, the light source 1 is not limited to a surface light source, and an arbitrary light source such as a point light source (see FIG. 6) can also be used.

  The present invention can be used for transparent light bulbs, chandeliers, general illumination lamps, and the like.

DESCRIPTION OF SYMBOLS 1 Surface light source 2 Optical element 3 Incident surface 4 1st area | region 5 2nd area | region (parabolic surface area | region)
6 Third region 7 Fourth region 8 Fifth region 11 Total reflection surface 12 Surface substantially parallel to optical axis 13 Surface not substantially parallel to optical axis

Claims (2)

An incident surface on which light is incident and an opposite surface to the incident surface. At least part of the light incident on a certain surface is totally reflected and refracted downward from the opposite surface to be emitted. A first region projecting in a conical shape, a second region located outside the incident surface, and reflecting light incident from the incident surface upwards substantially parallel to the optical axis, and the second region A plurality of total reflection surfaces that totally reflect light reflected upward in the region substantially parallel to the optical axis in a direction substantially perpendicular to the optical axis are repeatedly connected in a stepwise manner on a surface substantially parallel to the optical axis. The third region has a surface substantially parallel to the optical axis that refracts light emitted from the first region in a downward direction, and connects the first region and the third region. 4 and the light emitted from the first region is refracted in a downward direction and emitted. A fifth region having a surface substantially parallel to the optical axis that emits light emitted from the third region in a direction substantially perpendicular to the optical axis, and connecting the second region and the third region; An optical element comprising the optical element. An illumination device including a light source and an optical element,
The optical element is provided on an incident surface facing the light emitting surface of the light source, and on the side opposed to the incident surface by totally reflecting at least a part of light incident on a certain surface. A first region projecting in a cone shape that is refracted and emitted from the surface in a downward direction, and is positioned outward from the incident surface, and light incident from the incident surface is directed upward substantially parallel to the optical axis. And a plurality of total reflection surfaces that totally reflect light reflected upward by the second region in a direction substantially parallel to the optical axis in a direction substantially perpendicular to the optical axis. A third region repeatedly connected in a staircase pattern on substantially parallel surfaces, and a surface substantially parallel to an optical axis that refracts light emitted from the first region in a downward direction; A fourth region connecting the third region and the third region, and the outgoing light from the first region is directed downward A surface that is substantially parallel to the optical axis so that the light emitted from the third region is emitted in a direction substantially perpendicular to the optical axis, and the second region and the third region are emitted. A lighting device comprising: a fifth region connecting the regions.

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