JP5608538B2 - Lighting device - Google Patents

Description

  The present invention relates to an illuminating device that performs irradiation by guiding light from a light source to be branched and extended in a longitudinal direction.

  In general, when an illumination device is provided indoors, for example, in an automobile interior, an illumination device for occupant irradiation provided on the ceiling between the driver's seat and the passenger seat, an illumination device provided along the edge of the ceiling over the front and rear direction of the vehicle, and A lighting device or the like provided inside the door of an automobile is known.

  The purpose of the lighting device provided in the door trim of the automobile is to improve the visibility of the switch provided in the door trim, and to irradiate the inside of the pocket (storage part) provided in the door trim, thereby improving the workability of the passenger in the dark room Can be mentioned. As a form of installation of these lighting devices, there is one in which a light source and a light guide are provided on the surface of a door trim or inside a pocket and are turned on in response to a passenger's switch operation or door opening / closing.

  In recent years, as an object other than the workability of an occupant in the dark room, there is a form in which an ornament portion provided in a door trim functions as a lighting device in order to improve design. In this case, since the purpose is different from that of the lighting device described above, it is required that light is uniformly irradiated from the entire ornament member rather than irradiating an arbitrary position brightly. As an example for realizing this, a long-shaped light guide extending in the longitudinal direction (front-rear direction of the vehicle) is provided on the back side of the ornament member (between the ornament member and the door panel), and the ornament member that transmits light or the light-impermeable Illumination effect is obtained by leaking light from between the ornament member and door trim.

  In a normal longitudinal light guide, light sources are arranged at both ends, and light is irradiated from both ends. However, in the door trim of an automobile, the space for arranging the light source is limited, and the arrangement of the light source at both ends in the longitudinal direction of the light guide reduces the space for the irradiation part in the longitudinal direction. It is not preferable. Therefore, it is conventionally known to use a bifurcated light guide with a single light source.

  As an example of an illuminating device using this bifurcated light guide, there is a structure that is provided on a door grip and splits light incident from a light source and irradiates it in the front-rear direction of the door grip (for example, Patent Document 1). ). Moreover, an example of an illuminating device having a configuration in which a region in which a light beam incident on a side surface of a long light transmitting member is reflected and diffused in a longitudinal direction of the light transmitting member is provided (for example, Patent Document 2).

JP 2010-000841 A JP 2004-112830 A

  However, when light is diffused by a conventional bifurcated light guide, unevenness may occur in illumination light due to the appearance of a portion with high illuminance and a portion with low illuminance. The reason for this is that the amount of light emitted from the branching portion becomes non-uniform due to light reflection at the branching point (branch boundary) at the bifurcating branching portion. In addition, when the bifurcated side surfaces of the branched portion of the light guide have an acute angle with each other, the light irradiated from the branched portion is eliminated by light totally reflected by the inner surface of the bifurcated side surface, and the branched portion becomes a dark portion. Sometimes. In order to solve these problems, there is a method of attaching a light-shielding sheet, a light diffusion seal, or the like to the branch part, but this is not preferable from the viewpoint of increasing the number of work steps for the operator and increasing the cost.

  That is, in an illumination device that performs irradiation using a light guide that extends in the longitudinal direction within a limited space such as a conventional door trim, the light guide is used as an irradiator without arranging light sources at both ends of the light guide. It has been difficult to achieve maximum utilization and reduce unevenness of illumination light.

  In the present invention, when illumination is performed using a light guide extending in the longitudinal direction, it is possible to save space by arranging no light source at both ends in the longitudinal direction of the light guide, and illumination with less unevenness of illumination light is possible. An object of the present invention is to provide a simple lighting device.

  In order to achieve the above object, an illumination device according to the present invention includes a single light source, a light guide that guides light from the light source, and a light diffusion member that diffuses light, A light incident part on which light from the single light source is incident, a branch part for branching the incident light flux in at least two directions, and an irradiation part for extending light in the longitudinal direction from the branch part. And the light diffusing member is provided separately from the light guide and at a position adjacent to the branch side of the branch portion.

  According to this configuration, the light that is guided from the single light source and irradiated from the branch portion is diffused by the light diffusion member provided at a position adjacent to the branch side (inner side) of the branch portion, Unevenness of illumination light in the longitudinal direction of the light guide can be reduced. Thereby, even in the longitudinal light guide, space saving can be achieved without arranging light sources on both sides thereof, and illumination can be performed with substantially uniform illuminance with less unevenness of illumination light.

  In this illuminating device, it is preferable that the light guide has a notch portion formed so that a part of the branch portion including at least a branch portion has a small thickness. In this case, the light emitted from the branching portion is diffused and the amount of light emitted from the branching portion is adjusted uniformly, so that illumination with less unevenness of illumination light and illumination with a substantially uniform illuminance is achieved. It can be performed.

  The light diffusing member has a light diffusing shape (groove) formed in at least one of a light incident portion where light emitted from the branch portion is incident or a light exit portion where light is emitted from the light diffusing member. It may be. In this case, the light irradiated from the branch part can be effectively diffused.

  In the present invention, light that is guided from a single light source and irradiated from the branching portion is diffused by the light diffusion member, and the amount of light emitted from the branching portion is uniformly adjusted by the notch, thereby guiding the light. It can be set as the state with little unevenness of the illumination light in the longitudinal direction of the body. Thereby, even in the longitudinal light guide, it is possible to achieve space saving without arranging light sources on both sides of the light guide and to perform illumination with less unevenness of illumination light.

It is a top view which shows the structure of the illuminating device which concerns on this invention. It is the perspective view seen from the front direction which shows the door trim of the vehicle provided with the ornament which accommodated the illuminating device of FIG. It is a top view which shows the ornament back side of the vehicle which accommodated the illuminating device of FIG. (A) is AA sectional drawing of FIG. 3, (B) is BB sectional drawing. It is an enlarged view which shows the branch part of the light guide of FIG. It is a perspective view which shows the illuminating device which concerns on this invention. (A) is the top view of a branch part, (B) is the BB sectional drawing, (C) is the perspective view. It is a top view which shows a light-diffusion member. It is explanatory drawing which shows a test evaluation method.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing a configuration of a lighting device 1 according to the present invention. FIG. 2 is a perspective view of a door trim 31 of a vehicle provided with an ornament (interior member) 32 that houses the lighting device 1 as seen from the front. FIG. 3 is a plan view showing the back side of the ornament 32 of the vehicle housing the lighting device 1. As shown in FIG. 2, the ornament 32 is a member that extends in the longitudinal direction (longitudinal direction) X of the vehicle and has a substantially U-shaped cross section (FIG. 4), and is separate from the door trim 31 and the handle 34. Is disposed inside the door trim 31 and attached to the door trim 31 to be fixed.

  Since the ornament 32 has a substantially U-shaped cross section, the storage portion 51 of FIG. 3 is formed, and the light guide 3 of the lighting device 1 described later is stored in the storage portion 51. Is done. The ornament 32 is formed with a plurality of engaging claws 52 that protrude so as to close the storage portion 51 in the vertical direction Z of the vehicle orthogonal to the longitudinal direction X of the vehicle. When the light guide 3 is stored in the ornament 32, the light guide 3 is pushed into the storage portion 51 and stored while the engaging claw 52 is elastically deformed.

  4A is a cross-sectional view taken along the line AA in FIG. 3, and FIG. 4B is a cross-sectional view taken along the line BB. As shown in FIG. 4A, after the light guide 3 is stored in the ornament 32, the light guide 3 is dropped from the storage portion 51 by restoring the engaging claw 52 that has been elastically deformed. Is prevented. Further, the ornament 32 shown in FIG. 3 is formed with an attachment portion 53 that extends in the vertical direction Z of the vehicle. As shown in FIG. 4B, a screw or the like is provided in the attachment hole 54 of the attachment portion 53. The ornament 32 is fixed to the door trim 31 by inserting the fixture 55 and attaching the fixture 55 to the door trim 31.

  The ornament 32 shown in FIG. 2 is preferably made of a transparent material such as polycarbonate because it transmits light. When the ornament 32 is attached to the door trim 31, it is preferable in terms of the design that the design surface that is exposed to the inside of the vehicle is coated with an arbitrary color such as silver. According to this, the back surface of the ornament 32 is applied. The light emitted from the lighting device 1 on the side leaks from the gap between the ornament 32 and the door trim 31 to function as illumination. In addition, the form which does not provide the ornament 32 on the ornament 32, or the form which partially paints may be used.

  The illuminating device 1 of FIG. 1 includes a single light source 2, a bifurcated light guide 3 that guides light from the light source 2, and a light diffusion member 5 that diffuses light. The light source 2 and the light guide 3 are stored in the light source storage member 21 (FIG. 6). The light guide 3 includes a light incident part 11 on which light from a single light source 2 is incident, a branch part 13 that branches an incident light beam in at least two directions, and a light extending from the branch part 13 in the longitudinal direction X. And a cutout portion 16 formed so that a part of the branch portion 13 including at least a branch portion (branch boundary) is thinned. The light guide 3 is made of a transparent member such as an acrylic resin conventionally used, has a two-pronged shape that extends from the base end of the light incident portion 11, branches at the branch portion 13, and is divided into two directions. A single light source 2 is disposed adjacent to the base end of the eleventh. As the light source 2, an LED (light emitting diode) is preferable because it saves power and requires less installation space.

  In the light guide 3, a light introducing portion 12 is formed by linearly extending in the vertical direction Z perpendicular to the longitudinal direction X from the base end of the light incident portion 11 where light from the light source 2 enters. At the tip of the light introduction part 12 extending from the light incident part 11, there is a branch part 13 where the light guide 3 branches into two, and the light introduction part 12 extending in the vertical direction Z from a branch point (branch boundary) 13a. The irradiation portion 15 is formed so as to extend in a direction (longitudinal direction) X substantially orthogonal to the X direction. As shown in FIG. 5, the irradiation unit 15 has a shape that is long in the lateral direction (longitudinal direction X) with respect to the light introduction unit 12, whereby the light guide 3 as a whole is a longitudinal member that extends in the longitudinal direction X. It becomes. Moreover, the cross-sectional shape of the light guide 3 may be a conventionally used light guide shape such as a polygon such as a rectangle or an ellipse. In this example, the light introduction part 12 extends in the vertical direction Z, but this means that the thickness dimension is restricted by the thickness (door thickness) in the inside / outside direction Y of the vehicle (left and right side parts). For example, when there is no such restriction, the light introduction part 12 may be extended in the inner / outer direction Y as necessary.

  As shown in FIG. 5, a cutout portion 16, which is a groove cut out so that the thickness direction of the light guide 3 is thin, is formed in at least a part of the branching portion 13 including the branching portion (branch boundary) 13 a. Has been. By forming the notch 16, light can be emitted from the notch 16, and the amount of light emitted from the branch 13 can be adjusted uniformly. As a form of this notch part 13, what is necessary is just the form where the thickness of the light guide 3 becomes thin gradually toward the branch location 13a from the light incident part 11. FIG.

  As shown in FIG. 6, a light diffusion member 5 separate from the light guide 3 is disposed at a position adjacent to the branch side (inner surface side) of the branch portion 13. An example of the material is polycarbonate. The light diffusing member 5 may be a member integrated with the ornament 32. In this case, in the ornament 32 of FIG. 3, instead of the separate light diffusing member 5, a member in which a shape that becomes a light diffusing member protrudes in the rear surface direction Y of the ornament 32 is formed at that position. Since the light diffusing member 5 aims at diffusing the light emitted from the branch portion 13 by forming the notch portion 16, the light diffusing member 5 preferably has a form along the branch of the branch portion 13. As shown in FIG. 8, the light diffusing member 5 has a trapezoidal shape in a plan view, for example, and has a lower surface (light exit surface) than a side of the upper surface of the light diffusing member 5 (light incident surface where light enters from the branching portion). A trapezoidal solid with a long side is mentioned. Further, a light diffusing shape such as a groove may be formed on the light incident surface and the light exit surface, respectively, or one of them, and in this figure, triangular concave and convex grooves are formed on the light output surface in plan view. Together with these notches 16 and the light diffusing member 5, unevenness of illumination light in the longitudinal direction of the light guide 3 can be reduced.

  As shown in FIG. 6, the power supply to the light source 2 attached to the light source storage member 21 of the lighting device 1 is connected to the power source of a power window switch of a door (not shown) via the harness 22.

  Embodiments of the lighting device according to the present invention will be described below. Items common to the embodiments are as follows. The light guide 3 is made of, for example, PMMA, a square having a cross section of 5 mm × 5 mm, and the base end portion of the light incident portion 11 on which the light source 2 enters and the irradiation portion 15 have a cylindrical shape with a radius of 18 mm. The light source 2 is, for example, an LED light source (Nichia's NESW064), and the luminous flux is 1 (lumen). The light diffusing member 5 is made of polycarbonate, for example.

  7A is a plan view of the light guide 3, FIG. 7B is a sectional view taken along the line BB, and FIG. 7C is a perspective view thereof. As shown in FIG. 7C, the notch 16 is formed in the Z direction from the uppermost point (light guide surface) P1 (FIG. 7B) of the branch portion (branch boundary) 13a of the branch portion 13 toward the light source 2. Point P3 that is a predetermined distance away (for example, 2.89 mm), two points P4 that are a predetermined distance apart from each other in the X direction from the branch point 13a toward the irradiation unit 15, and the lowest point of the branch point 13a (back surface of the light guide) It consists of a groove having four points P2 on the same plane. The notch (groove) 16 has a substantially isosceles triangular shape with the point P2 as a vertex and an extended line from the point P2 to the points P4 and P4 as both sides.

  The light diffusing member 5 in FIG. 8 is a member having a trapezoidal surface with an upper side of 5 mm and a lower side of 9 mm, a height of 3 mm, and a thickness of 5 mm, for example. In this figure, a triangular concave / convex groove is formed on the light exit surface, but in some embodiments, a triangular concave / convex groove is formed on both sides. The following 10 patterns were evaluated by combining the patterns of the notches 16 and the light diffusing member 5. As a comparative example, an illuminating device in which the branch part 13 does not form the notch part 16 and does not have the light diffusion member 5 is used.

Example 1
A notch portion is formed in the branch portion, the light incident surface of the light diffusing member is a flat surface (no groove), and the light exit surface has a triangular concave and convex groove with an apex angle of 90 degrees and a height of 0.5 mm.
(Example 2)
A notch portion is formed in the branch portion, and no light diffusing member is set.
(Example 3)
A notch portion is formed in the branch portion, and the light incident surface of the light diffusing member is a flat surface (no groove), and the light exit surface is a flat surface (no groove).
Example 4
A notch portion is formed in the branch portion, and a triangular concave and convex groove having an apex angle of 90 degrees and a height of 0.5 mm is provided on the light incident surface and the light outgoing surface of the light diffusion member.
(Example 5)
A notch portion is formed in the branch portion, the light incident surface of the light diffusing member has a triangular concave / convex groove having an apex angle of 90 degrees and a height of 0.5 mm, and the light output surface is a flat surface (no groove).
(Example 6)
A notch portion is formed in the branch portion, the light incident surface of the light diffusing member is a flat surface (no groove), and the light exit surface has a triangular concave and convex groove with a vertex angle of 60 degrees and a height of 0.5 mm.
(Example 7)
A notch portion is formed in the branch portion, the light incident surface of the light diffusing member is a flat surface (no groove), and the light exit surface has triangular concave and convex grooves with an apex angle of 120 degrees and a height of 0.5 mm.
(Example 8)
A notch portion is formed in the branch portion, the light incident surface of the light diffusing member is a flat surface (no groove), and the light exit surface has a triangular concave and convex groove with an apex angle of 90 degrees and a height of 1.0 mm.
Example 9
A notch portion is formed in the branch portion, the light incident surface of the light diffusing member is a flat surface (no groove), and the light exit surface has an arc-shaped uneven groove having a radius of 0.45 mm.
(Example 10)
Without forming a notch in the branch part, the light incident surface of the light diffusing member is a flat surface (no groove), and the light exit surface has a triangular concave and convex groove with an apex angle of 90 degrees and a height of 0.5 mm. .
(Comparative example)
A light diffusing member is not set without forming a notch in the branch portion.

About Examples 1-10 mentioned above and a comparative example, it evaluated on the following conditions. As shown in FIG. 9, an evaluation surface serving as a plane covering the branch portion 13 was provided. The evaluation surface is a rectangular surface in which the thickness direction (height) of the light guide 3 is, for example, 10 mm and the longitudinal direction (width) is 22 mm. This evaluation surface was divided into strips with a pitch of 2 mm in the width 22 mm direction, and illuminance data was taken on each divided surface (unit: lm / m ² ). In one embodiment, the value of the surface with the lowest illuminance (minimum value) and the value of the surface with the highest illuminance (maximum value) are extracted, and the value obtained by dividing the minimum value by the maximum value is defined as the degree of uniformity. The closer the value is to 1, the better the illumination light is uneven. The results are as shown in Table 1. In the comparative example, the illuminance at the branch portion was 0 (dark portion), and the presence of unevenness in the illumination light became clear. On the other hand, although the effect was different for each example, good results were obtained for the comparative example.

  As described above, in the present invention, light that is guided from the single light source 2 and irradiated from the branch portion 13 is diffused by the light diffusion member 5, and the amount of light emitted from the branch portion 13 is uniform by the notch portion 16. By adjusting to, unevenness of illumination light in the longitudinal direction of the light guide 3 can be reduced. Thereby, even in the elongated light guide 3, space saving can be achieved without arranging light sources on both sides thereof, and illumination can be performed with substantially uniform illuminance with less unevenness of illumination light.

  In this embodiment, the present illumination device that performs illumination using a light guide that extends in the longitudinal direction is used for illumination in the ornament of a vehicle door trim. You may use for the illumination in the aspect installed in this limited space.

  As described above, the preferred embodiment of the present invention has been described with reference to the drawings, but various additions, modifications, or deletions can be made without departing from the spirit of the present invention. Included within the scope of the invention.

1: Illumination device 2: Light source (LED)
3: Light guide 5: Light diffusion member 11: Light incident part 13: Branch part 13a: Branch part 15: Irradiation part 16: Notch part

Claims (2)

A single light source, a light guide that guides light from the light source, and a light diffusion member that diffuses light,
The light guide includes a light incident portion on which light from the single light source is incident, a branch portion that branches the incident light flux in at least two directions, and a light that extends in the longitudinal direction from the branch portion. An irradiation unit, and
The light diffusing member is provided separately from the light guide, at a position adjacent to the branch side of the branch portion,
The said light guide is an illuminating device which has a notch part formed so that the thickness might become thin in a part including the branch location at least of the said branch part . The lighting device according to claim 1, wherein the notch is formed such that the thickness of the light guide gradually decreases from the light incident portion toward the branching portion .

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