JP2024054689A - Lighting equipment - Google Patents

Abstract

[Problem] To provide a lighting device that suppresses light leakage from the end of a light guide and enables illumination of a desired area. [Solution] The lighting device 1 includes a light source unit 10, a light guide 20 that is an elongated light guide and guides light incident on one end 21 from the light source unit 10 in the longitudinal direction of the elongated shape toward the other end 22 and emits light from a surface 23 of the light guide in an emission direction substantially perpendicular to the longitudinal direction, and a housing 30 that supports the light guide 20 and has an opening 35 that passes the light emitted from the light guide 20 and irradiates an external interior panel, and the other end 22 side of the light guide 20 is bent so as to be hidden on the back side of an interior panel 104 (first interior panel 102) in a direction away from the opening 35 to form the lighting device 1. This suppresses light leakage from the end of the light guide and enables illumination of a desired area. [Selected Figure] Figure 3

Description

The present invention relates to a lighting device.

A long lighting device that is mounted on, for example, an instrument panel in the interior of a vehicle has been disclosed (see, for example, Patent Document 1). This lighting device includes a panel body with a cover panel fixed to the instrument panel in the interior of the vehicle, and a lighting unit provided inside the panel body. The panel body is attached and fixed to the instrument panel. The panel body has an opening that forms a gap between the panel body and the instrument panel, and a columnar light guide is housed inside. Light is incident on the light guide from a light source unit at one end in the longitudinal direction, and the light is guided toward the other end. This guided light is configured to be irradiated from the surface of the columnar light guide through the opening into the interior of the vehicle.

Also disclosed is a long lighting device that is mounted on, for example, an instrument panel in the passenger compartment of a vehicle (see, for example, Patent Document 2). This lighting device is a lighting device for the passenger compartment in which a light-guiding lighting member is arranged on the instrument panel at the front of the passenger compartment, and a clear cover body that is substantially see-through is arranged in the vicinity of the lighting member on the instrument panel. In the lighting device, the lighting member is accommodated in a groove formed to extend in the vehicle width direction, and the groove that accommodates the lighting member is open so as to face the lower surface. This opening is closed by a cover body (clear cover body) that is a substantially see-through clear member. Light from the light source unit is incident on the lighting member from an end face, and the illumination light from the lighting member is irradiated from the surface of the lighting member.

JP 2009-184421 A JP 2006-103373 A

However, according to the configuration of Patent Document 1, the light guide is configured such that light is incident from a light source unit at one end of the light guide, the light is guided toward the other end, and the light is irradiated from the surface of the light guide through an opening and into the vehicle interior. Similarly, according to the configuration of Patent Document 2, the lighting member is configured such that light is incident from a light source unit at an end face of the lighting member, the light is guided toward the other end, and the light is irradiated from the surface of the lighting member through the opening and the cover body and into the vehicle interior.

This caused a problem in that light would leak from one end of the light guide where the light source enters, through the other end of the light guide located on the opposite side, causing the light to be reflected in unintended locations.

Therefore, the object of the present invention is to provide a lighting device that suppresses light leakage from the ends of the light guide and enables illumination of the desired area.

[1] The present invention provides an illumination device comprising: a light source unit; a light guide which is an elongated light guide and guides light incident on one end from the light source unit in a longitudinal direction of the elongated shape toward the other end and emits the light from a surface of the light guide in an emission direction approximately perpendicular to the longitudinal direction; and a housing which supports the light guide and has an opening through which light emitted from the light guide passes and is irradiated onto an external interior panel, wherein the other end side of the light guide is bent so as to be hidden on the back side of the interior panel in a direction away from the opening.
[2] The opening may be disposed in a gap between a first interior panel oriented in a horizontal direction and a second interior panel oriented in a vertical direction.
[3] The light guide may have a circular cross section, and the bent region may be gradually thinner from the circular cross section toward the other end portion on the opening side.
[4] The bent region may be formed so that the circular shape gradually becomes thinner in a stepped shape.
[5] The light guide may be disposed in a width direction of the vehicle, and the light emitted from the opening may indirectly illuminate an interior panel.

The lighting device of the present invention can prevent light from escaping from the ends of the light guide, making it possible to illuminate the desired area.

FIG. 1 is a front view showing the interior of a vehicle as an example in which a lighting device according to an embodiment of the present invention is mounted, looking toward the front of the vehicle from within the vehicle interior. FIG. 2(a) is a three-dimensional perspective view showing an interior panel and an opening illuminated by a lighting device according to an embodiment of the present invention, and FIG. 2(b) is a three-dimensional perspective view showing, by hatching, the area of the interior panel illuminated by light irradiated from the opening by the lighting device. 3(a) is an overall view including the light guide, housing, and light source unit as viewed from direction A in FIG. 1 (upward from the vehicle), FIG. 3(b) is an overall view including the light guide, housing, and light source unit as viewed from direction B in FIG. 3(a) (from the rear to the front of the vehicle), and FIG. 3(c) is an enlarged cross-sectional view showing the CC section of FIG. 3(a). 4(a) is a partial plan view of the first interior panel and the opening seen from direction A in FIG. 1 (from the top of the vehicle), FIG. 4(b) is a partial plan view showing the light guide and housing in FIG. 4(a), and FIG. 4(c) is a partial front view of the light guide and housing seen from direction B in FIG. 4(b) (from the rear to the front of the vehicle). Figure 5(a) shows the positional relationship between the second interior panel in area D shown in Figure 1 and the light guide shown in Figure 3(b), and is a front view of the second interior panel as an interior panel from the rear to the front of the vehicle, Figure 5(b) is a diagram showing the lighting state when the interior panel is illuminated by a lighting device related to an embodiment of the present invention, and Figure 5(c) is a diagram showing the lighting state when the interior panel is illuminated by a lighting device related to a comparative example.

[Embodiments of the present invention]
The lighting device 1 according to an embodiment of the present invention comprises a light source unit 10, a light guide 20 which is an elongated light guide that guides light incident on one end 21 from the light source unit 10 in the longitudinal direction of the elongated shape toward the other end 22 and emits light from a surface 23 of the light guide in an emission direction approximately perpendicular to the longitudinal direction, and a housing 30 which supports the light guide 20 and has an opening 35 through which the light emitted from the light guide 20 passes and is irradiated onto an external interior panel, and the other end 22 side of the light guide 20 is bent so as to be hidden on the back side of the interior panel 104 (first interior panel 102) in a direction away from the opening 35.

The lighting device 1 according to the embodiment of the present invention irradiates light to the outside from the elongated opening 35, so the object onto which the light is irradiated can be a variety of objects or decorative surfaces.

Figure 1 is a front view of a vehicle interior as an example in which a lighting device according to an embodiment of the present invention is installed, looking forward from within the vehicle interior. Also, Figure 2(a) is a three-dimensional perspective view showing an interior panel and an opening illuminated by a lighting device according to an embodiment of the present invention, and Figure 2(b) is a three-dimensional perspective view showing, by hatching, an area of the interior panel illuminated by light irradiated from the opening by the lighting device. The instrument panel 101 is configured to have an interior panel 104 that includes a first interior panel 102 facing in the horizontal direction of the vehicle 100 and a second interior panel 103 facing in the vertical direction.

In an embodiment of the present invention, as an example, the lighting device 1 is disposed in the gap between the first interior panel 102 and the second interior panel 103. That is, as shown in FIG. 2(a), the housing 30 that houses the light guide 20 therein is disposed in the gap between the first interior panel 102 and the second interior panel 103, and the opening 35 is disposed in the gap between the first interior panel 102 that faces horizontally and the second interior panel 103 that faces vertically.

In addition, in the embodiment of the present invention, a case will be described in which the lighting device 1 illuminates (indirect illumination) the second interior panel 103 as an interior panel. That is, the light guide 20 is arranged in the vehicle width direction of the vehicle 100, and as shown in FIG. 2(b), the light emitted from the opening 35 illuminates (indirect illumination) the second interior panel 103. Note that in FIG. 2(b), the illuminated area 200 of the second interior panel 103 is illustrated by hatching. In this way, the lighting device 1 can function as indirect illumination in the vehicle cabin, for example, in the instrument panel 101.

(Light source unit 10)
Fig. 3(a) is an overall view including the light guide, the housing, and the light source unit as viewed from the direction A (upward direction of the vehicle) in Fig. 1, Fig. 3(b) is an overall view including the light guide, the housing, and the light source unit as viewed from the direction B (from the rear to the front direction of the vehicle) shown in Fig. 3(a), and Fig. 3(c) is an enlarged cross-sectional view showing the CC cross section of Fig. 3(a). The light source unit 10 generates light for entering the inside of the light guide 20 from one end 21 of the light guide 20.

As an example, the light source unit 10 uses an LED (Light Emitting Diode) element, but various light sources such as an EL (Electro Luminescence) element or a light bulb can be used. The light source unit 10, which is an LED element, mainly emits visible light and can emit white light, light of each color of R, G, and B, or light of any color that is a mixture of these. As a result, the illumination light that is guided from the light source unit 10 by the light guide 20 and irradiated onto the illumination object, for example, the second interior panel 103, can be set to various colors and any illuminance.

(Light guide 20)
As shown in Figs. 3(a), (b), (c) and 4(a), (b), (c), the light guide 20 is a light guide formed in a long columnar shape using a light-transmitting material for guiding light from the light source unit 10 and emitting it to the outside. For the light guide 20, for example, a resin with high transparency such as PC (PolyCarbonate) or PMMA (PolyMethylMethacrylate) can be used. The light guide 20 is a long columnar shape, and the cross-sectional shape thereof can be various shapes such as a circle, a rectangle, a trapezoid, etc., but in this embodiment, the light guide 20 is a circle.

As shown in FIG. 3(a), the light emitted from the light source unit 10 is incident on one end 21 of the light guide 20. The light incident on the light guide 20 is guided in the longitudinal direction of the light guide 20 to the other end 22. As shown in FIG. 3(c), the surface 23 of the light guide 20 emits light L in an emission direction that is approximately perpendicular to the longitudinal direction. In this embodiment, the light guide 20 emits light L toward the upper direction of the vehicle so that it can be irradiated onto the second interior panel 103.

As described above, it is preferable that a plurality of light scattering sections are formed along the longitudinal direction on the underside 24 of the light guide 20 so that the light L is emitted from the surface 23 of the light guide 20 toward the upper direction of the vehicle. The light scattering sections are, for example, approximately V-shaped recesses formed along the longitudinal direction on the underside 24 side of the light guide 20. The angle of the V-shape can be set arbitrarily taking into account the direction and strength of light scattering. As a result, the light guided from the light source unit 10 is irradiated as light L from the surface 23 of the light guide 20 to the second interior panel 103, which is the interior panel that is the irradiation target, as shown in Figures 2(a), (b), and 3(c).

As shown in FIG. 3(a), the light guide 20 is in a long columnar shape, and the other end 22 side is bent relative to the center line CL in the longitudinal direction of the column. Here, as shown in FIG. 3(c) and FIG. 4(a), the light guide 20 is bent so that the other end 22 side of the light guide 20 is hidden in the back side 102a of the first interior panel 102 serving as an interior panel, in the direction away from the opening 35 (direction E). Note that, as shown in FIG. 3(a), the bending of the other end 22 side of the light guide 20 may or may not completely straddle the center line CL at the upper side.

Light guided from the light source unit 10 leaks out from this bent tip side, i.e., the other end 22 side of the light guide 20, but this light leaks away from the interior panel (second interior panel 103) that is the target of illumination, and is irradiated so as to be hidden behind the interior panel (first interior panel 102). This prevents the problem of light leaking and being reflected in unintended locations, and makes it possible to provide a lighting device that suppresses light leakage from the end of the light guide and enables localized illumination of the area to be illuminated.

As shown in Figures 3(b) and 4(c), the light guide 20 has a circular cross section, and the bent region is formed so that the opening 35 side gradually becomes thinner from the circular cross section toward the other end 22 side. Also, as shown in Figures 4(b) and (c), the bent region may be formed so that the cross section gradually becomes thinner in a stepped shape from the circular cross section.

As mentioned above, by bending the tip of the light guide 20 so that it is hidden behind the interior panel, the amount of light emitted onto the projection surface of the second interior panel 103 as an interior panel decreases, and the brightness changes suddenly and becomes dark, which may make the lighting look unnatural. Therefore, in order to make the lighting look natural, the tip of the light guide 20 is gradually made thinner (stepped shape) from the optimal circular shape, the light guided is reduced, and the amount of light is adjusted by converting it into outgoing light, improving the light emission toward the second interior panel 103 as an interior panel and controlling the light emission toward the outside of the vehicle (behind the interior panel). This suppresses light leakage from the end of the light guide 20 and controls the lighting to the part to be illuminated, making it possible to achieve lighting that looks natural without a sudden change in brightness (darkness).

(Housing 30)
As shown in FIG. 3C, the housing 30 is a frame body attached to the vehicle side, which supports the light guide 20 and has an opening 35 through which light emitted from the light guide 20 passes and is irradiated to an external interior panel. The opening 35 is formed of a transparent material in accordance with the elongated light guide 20, or is formed as a long hole penetrating the light guide 20. As an example, the frame portion of the housing 30 can be formed of a synthetic resin such as ABS (Acrylonitrile Butadiene Styrene). Note that the housing 30 may be a frame body that supports the light guide 20 and is attached to the vehicle side, and in this embodiment, the opening 35 may be formed by a gap between the first interior panel 102 and the second interior panel 103.

Figure 5(a) shows the positional relationship between the second interior panel in area D shown in Figure 1 and the light guide shown in Figure 3(b), and is a front view of the second interior panel as an interior panel from the rear to the front of the vehicle, Figure 5(b) is a diagram showing the lighting state when the interior panel is illuminated by a lighting device according to an embodiment of the present invention, and Figure 5(c) is a diagram showing the lighting state when the interior panel is illuminated by a lighting device according to a comparative example.

When the second interior panel 103, which is an interior panel, is illuminated by the lighting device 1 according to the embodiment of the present invention, it can be seen that the illuminated area 200 of the second interior panel 103 is illuminated, as shown in FIG. 5(b). This shows that the lighting device 1 is illuminating (indirectly illuminating) the illuminated area 200 of the second interior panel 103, which is shown hatched in FIG. 2(b), i.e., the intended illumination area, with uniform light as the illumination area 201, as shown in FIG. 5(b).

In addition, in areas other than the intended illumination area, unintended illumination light due to leakage of illumination light, etc. cannot be seen. In other words, the other end 22 side of the light guide 20 is configured to be bent so as to be hidden on the back side of the interior panel (first interior panel 102) in a direction away from the opening 35, and this configuration means that light is not irradiated from the other end 22 side of the light guide 20 in the direction of the interior panel to be irradiated. This prevents the problem of light being reflected in unintended locations due to light leakage from occurring, and suppresses light leakage from the end of the light guide, making it possible to provide localized illumination of the area to be irradiated.

In the area 200 where the second interior panel 103 is illuminated, the illumination state of the illumination area 201 shown in FIG. 5(b) is uniform, and no sudden changes in brightness are felt. This is because the tip side of the light guide 20 is gradually made thinner (stepped) from the optimal circular shape, reducing the guided light and converting it into outgoing light to adjust the amount of light, thereby controlling the light emission in the direction of the second interior panel 103 as an interior panel to be improved.

Figure 5 (c) shows, as a comparative example, an illumination state in which a second interior panel 103 serving as an interior panel is illuminated by an illumination device using a type of light guide 20 that does not have a bend at the tip end. As shown in Figure 5 (c), the illumination device of the comparative example illuminates (indirectly illuminates) the illumination area 202 of the second interior panel 103 serving as an interior panel.

However, in the illuminated area 200 of the second interior panel 103 shown by hatching in FIG. 2(b), i.e., in an area other than the intended illuminated area, unintended illumination 203 shown in FIG. 5(c) is visible. This is thought to be because there is no bending at the tip end of the light guide 20, which causes light to leak out from the tip end of the light guide 20, resulting in the problem of light being reflected in unintended locations.

[Advantages of the embodiment of the present invention]
(1) The lighting device 1 according to the embodiment of the invention includes a light source unit 10, a light guide 20 that is an elongated light guide and guides light incident on one end 21 from the light source unit 10 in the longitudinal direction of the elongated shape toward the other end 22 and emits light from a surface 23 of the light guide in an emission direction substantially perpendicular to the longitudinal direction, and a housing 30 that supports the light guide 20 and has an opening 35 that passes the light emitted from the light guide 20 and irradiates an external interior panel, and the other end 22 side of the light guide 20 is bent so as to be hidden on the back side of the interior panel (first interior panel 102) in a direction away from the opening 35. This bending of the other end 22 side of the light guide 20 can suppress light leakage from the other end 22 side of the light guide 20 toward the interior panel. This prevents the problem of light being reflected in unintended places due to light leakage, suppresses light leakage from the end of the light guide, and enables localized illumination of the area to be irradiated.
(2) The lighting device 1 gradually thins the tip side of the light guide 20 from an optimal circular shape (step shape) to reduce the guided light and convert it into outgoing light, thereby adjusting the amount of light and controlling it to improve light emission toward the second interior panel 103 as an interior panel. As a result, in the illuminated area 200 of the second interior panel 103 as an interior panel, sudden changes in brightness are suppressed, resulting in a uniform illumination state.
(3) The opening 35 of the lighting device 1 is disposed in the gap between the first interior panel 102 oriented in the horizontal direction and the second interior panel 103 oriented in the vertical direction. This allows the lighting device 1 to function as indirect illumination for, for example, the instrument panel 101 in the passenger compartment of the vehicle.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications are possible within the scope of the gist of the invention. Furthermore, the above embodiments do not limit the invention according to the claims. It should be noted that not all of the combinations of features described in the embodiments are necessarily essential to the means for solving the problems of the invention.

Reference Signs List 1... Illumination device 10... Light source unit 20... Light guide, 21... One end, 22... Other end, 23... Surface, 24... Bottom surface 30... Housing, 35... Opening 100... Vehicle, 101... Instrument panel, 102... First interior panel, 102a... Back side, 103... Second interior panel, 104... Interior panel 200... Area, 201... Illumination area, 202... Illumination area, 203... Illumination by unintended light CL... Center line L... Light

Claims (5)

A light source unit;
a light guide that is an elongated light guiding body, guiding light incident from the light source unit to one end thereof in a longitudinal direction of the elongated shape toward the other end thereof, and emitting the light from a surface of the light guiding body in an emission direction substantially perpendicular to the longitudinal direction;
a housing that supports the light guide and has an opening through which light emitted from the light guide passes and is irradiated onto an external interior panel;
The other end of the light guide is bent so as to be hidden behind the interior panel in a direction away from the opening. The lighting device according to claim 1, wherein the opening is disposed in a gap between a first interior panel oriented horizontally and a second interior panel oriented vertically. The illumination device according to claim 1 , wherein the light guide has a circular cross section, and the bent region is gradually tapered from the circular cross section toward the other end portion. The lighting device according to claim 3, wherein the curved area is gradually tapered from the circular shape to a stepped shape. The lighting device according to claim 1 , wherein the light guide is disposed in a width direction of the vehicle, and the light emitted from the opening indirectly illuminates the interior panel.