Interior lighting

Abstract

To provide a vehicular interior lighting device which improves a degree of freedom in design.SOLUTION: A vehicular interior lighting device 1 includes: a light source 20; a bus bar 14 which has a plate-like electrode section 14a; a lens 13 which has a light transmission section 13a and a holding structure section 13b; conductive films 30 which are formed in a part of the lens 13; and a control section 22 which switches on / off of the light source 20 according to a change of electrostatic capacitance between a finger tip F touching a light irradiation surface 13c and the electrode section 14a. The holding structure section 13b has a first side wall section 13f as a wall section with which a second main plane 14d of the electrode 14a is brought into contact and is positioned outside a light receiving surface 13d in an irradiation direction view of light. The conductive films 30 are formed on the light receiving surface 13d and a first outer wall surface 13h on an opposite side of a first inner wall surface 13i as a surface with which the second main plane 14d of the electrode section 14a is brought into contact in the first side wall section 13f. The conductive film 30 formed on the light receiving surface 13d and the conductive film 30 formed on the first outer wall surface 13h are continued to each other.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a vehicle interior lighting device. [Background technology]

[0002] Conventionally, there are devices installed in the passenger compartment of an automobile to illuminate the interior of the vehicle. Patent Document 1 discloses technology related to a vehicle interior lighting device that turns on and off when a part of the human body touches the light-emitting surface of a lens facing the interior of the vehicle. In this technology, a part of the light-transmitting part of the lens and the annular electrode part of the bus bar are in contact with each other via a part of the housing (inner cover). The bus bar also contacts an electrode pad on a circuit board that is electrically connected to a control unit. Therefore, when a part of the human body touches the light-emitting surface of the lens, the control unit can detect a change in capacitance between the annular electrode part and the human body and switch the light source on and off. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-12257 Summary of the Invention [Problem to be solved by the invention]

[0004] In the vehicle interior lighting device disclosed in Patent Document 1, the annular electrode portion of the bus bar is aligned with the outer periphery of the light-transmitting portion of the lens and is arranged parallel to the light-irradiated surface. The housing is made of opaque resin. Therefore, the fact that the part of the housing that tightly contacts the back side of the bus bar is located on the back side of the light-transmitting portion of the lens has the advantage that the bus bar is not visible from inside the vehicle cabin, but it can also be said that this reduces the degree of freedom in designing the vehicle interior lighting device.

[0005] The present invention has been made in view of the problems inherent in the prior art, and an object of the present invention is to provide a vehicle interior lighting device that improves the degree of freedom in design. [Means for solving the problem]

[0006] An interior lighting device according to one aspect of the present invention includes a lens having a light source, a bus bar having a flat electrode portion and being conductive, a light-transmitting portion that transmits light emitted from the light source toward the interior of the vehicle cabin, and a holding structure portion that holds the electrode portion; a light-transmitting conductive film formed on a part of the lens; and a control unit that switches the light source on / off in accordance with a change in capacitance between the electrode portion and a part of a human body that touches the light-irradiating surface of the light-transmitting portion, wherein the holding structure portion has a wall portion that contacts the main plane of the electrode portion and is located outside the light-receiving surface that is on the back side of the light-irradiating surface when viewed in the light-irradiating direction, and the conductive film is formed on the light-receiving surface and on an outer wall surface of the wall portion of the holding structure portion opposite to the surface with which the main plane of the electrode portion contacts, and the conductive film formed on the light-receiving surface and the conductive film formed on the outer wall surface are continuous with each other. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is an external perspective view of a vehicle interior lighting device according to an embodiment of the present invention; [Figure 2] 1 is an exploded perspective view of a vehicle interior lighting device according to an embodiment of the present invention. [Figure 3A] 10 is a perspective view of a lens that allows the light receiving surface and the second outer wall surface to be seen. FIG. [Figure 3B] 10 is a perspective view of a lens that allows the light receiving surface and the first outer wall surface to be seen. FIG. [Figure 4A] FIG. 2 is a perspective view of a bus bar that allows a first main plane of an electrode portion to be seen. [Figure 4B] FIG. 2 is a perspective view of the bus bar, allowing the second main plane of the electrode portion to be seen. [Figure 5] 2 is a partial cross-sectional view of the vehicle interior lighting device, corresponding to the VV cross section of FIG. 1. [Figure 6] 6 is a partial cross-sectional view of the vehicle interior lighting device corresponding to the cross section VI-VI of FIG. 1. [Figure 7] 10A and 10B are partial cross-sectional views of a vehicle interior lighting device illustrating a housing having another shape. DETAILED DESCRIPTION OF THE INVENTION

[0008] The vehicle interior lighting device according to the present embodiment will be described in detail below with reference to the drawings. Note that the dimensional proportions in the drawings are exaggerated for the sake of convenience and may differ from the actual proportions.

[0009] 1 is a perspective view showing the exterior of a vehicle interior lighting device 1 according to this embodiment. The vehicle interior lighting device 1 is installed in the interior of a vehicle such as an automobile to illuminate the interior of the vehicle. The vehicle interior lighting device 1 has a capacitive touch switch structure that allows an occupant to switch the vehicle interior lighting device 1 on and off by touching a light irradiation surface 13c of a lens 13, which is a part of the vehicle interior lighting device 1.

[0010] In the following drawings, each direction based on the XYZ coordinate system is illustrated. The Z direction corresponds to the light irradiation direction perpendicular to the light irradiation surface 13c of the lens 13, and, referring to FIG. 2, also corresponds to the assembly direction of the components constituting the vehicle interior lighting device 1. The X and Y directions are perpendicular to each other and are also perpendicular to the Z direction. Of these, the X direction corresponds to the juxtaposition direction of the two light sources 20.

[0011] 2 is an exploded perspective view of the vehicle interior lighting device 1. The vehicle interior lighting device 1 includes a substrate 10, a prism 11, a housing 12, a lens 13, a bus bar 14, a console 15, and a bezel 16.

[0012] The substrate 10 includes a light source 20, an electrode pad 21, a control unit 22, and a connector unit 23. The light source 20 is, for example, an LED (light-emitting diode) that emits light for illumination. In this embodiment, there are two light sources 20, for example. The electrode pad 21 contacts a portion of the substrate connection portion 14b of the bus bar 14. In this embodiment, a bus bar 14 is provided for each light source 20, and therefore two electrode pads 21 are provided on the same surface of the substrate 10 as the light source 20. The control unit 22 controls the overall functions of the interior lighting device 1 and includes at least a microcomputer that controls electrostatic touch. The control unit 22 is electrically connected to the electrode pad 21. When a part of the human body, such as a fingertip F (see FIG. 5 ), touches the light irradiation surface 13c of the lens 13, the control unit 22 detects a change in capacitance between the electrode portion 14a of the bus bar 14 and the human body and switches the light source 20 on and off. The connector portion 23 is connected to a connector on the side of a wire harness routed inside a vehicle in which the vehicle interior lighting device 1 is installed.

[0013] The prisms 11 are optical elements provided directly above the light sources 20, respectively, and configured to bend the light emitted from the light sources 20 in any direction. The prisms 11 are integrally molded from an insulating and optically transparent synthetic resin or the like.

[0014] The housing 12 is a structure disposed opposite the surface of the substrate 10 on which the light source 20 is provided. The housing 12 is integrally molded from an insulating, light-opaque synthetic resin or the like. The housing 12 is also sometimes referred to as an inner cover. The housing 12 has two reflector portions 12a spaced apart from each other in accordance with the positions of the two light sources 20 on the substrate 10. The two reflector portions 12a are symmetrical to each other and each has a reflective portion 12b, a support frame portion 12c, and a lens-opposing portion 12j (see FIG. 5 or FIG. 6).

[0015] The reflecting portion 12b is a wall portion that reflects light emitted from the light source 20 and transmitted through the prism 11 and guides the light to the light transmitting portion 13a of the lens 13. The reflecting portion 12b has, for example, a truncated quadrangular pyramid shape that widens from a first opening to a second opening along the Z direction. In this case, the first opening at the apex of the reflecting portion 12b connects to the light exit portion of the prism 11. Meanwhile, the second opening at the base of the reflecting portion 12b opens toward the light transmitting portion 13a.

[0016] The support frame 12c is a collection of walls surrounding a first space S1, which includes an optical path through which light emitted from the light source 20 passes before reaching the light-transmitting portion 13a of the lens 13. Specifically, the support frame 12c is configured by a combination of two walls that are approximately parallel to the XZ plane and two walls that are approximately parallel to the YZ plane. The support frame 12c supports the reflecting portion 12b via the lens-facing portion 12j on the side closer to the light-transmitting portion 13a in the Z direction. Since the two reflector portions 12a of the housing 12 are spaced apart from each other in the X direction, a second space S2 is defined between the two reflector portions 12a. In the second space S2, at least the side of the housing 12 where the bezel 16 is attached is open.

[0017] The lens facing portion 12j is located at the top of the housing 12 in the Z direction and is a wall portion parallel to the light transmitting portion 13a of the lens 13. The shape of the lens facing portion 12j is annular when viewed in the Z direction and is set to match the shape of the outer periphery of the light transmitting portion 13a. The surface of the lens facing portion 12j that faces the light transmitting portion 13a is the lens contact surface 12d. However, in this embodiment, the lens contact surface 12d does not directly contact the light receiving surface 13d of the light transmitting portion 13a, but rather indirectly contacts the light receiving surface 13d via a conductive film 30 that is formed in advance on the light receiving surface 13d.

[0018] The housing 12 also has, for example, first protrusions 12g at multiple locations on the wall that constitutes the support frame 12c, which function as a locking mechanism when the lens 13 is attached to the housing 12. The housing 12 also has, for example, first protrusions 12f at multiple locations on the wall that constitutes the support frame 12c, which protrude in the Z direction toward the console 15 and function as a locking mechanism when the housing 12 is attached to the console 15. The first protrusions 12f are each formed with a first engagement hole 12h that engages with a second protrusion 15b that is provided in advance on the console 15.

[0019] 3A and 3B are perspective views of the lens 13. FIG. 3A is a view that allows the light receiving surface 13d and a second outer wall surface 13k located on the side of the holding structure 13b opposite the reflector portion 12a when the lens 13 is attached to the housing 12 to be seen. FIG. 3B is a view that allows the light receiving surface 13d and a first outer wall surface 13h located on the side of the holding structure 13b facing the reflector portion 12a when the lens 13 is attached to the housing 12 to be seen. A lens 13 is provided for each reflector portion 12a provided in the housing 12, i.e., for each light source 20. Therefore, in this embodiment, two lenses 13 are provided so as to be spaced apart in accordance with the positions of the two reflectors 12a. The two lenses 13 are symmetrical to each other.

[0020] The lens 13 is an optical component that transmits at least a portion of the light emitted from the light source 20 and guides the light into the vehicle interior. The lens 13 is integrally molded from an insulating and light-transmitting synthetic resin or the like. However, the lens 13 is not limited to a transparent material, and may be a so-called translucent material. The lens 13 has a light-transmitting portion 13a and a holding structure portion 13b.

[0021] The light-transmitting portion 13a is a flat portion that transmits light irradiated from the reflector portion 12a side toward the interior of the vehicle. One of the main planes of the light-transmitting portion 13a is a light-irradiating surface 13c that faces the interior of the vehicle. The light-irradiating surface 13c is a design surface because it faces the interior of the vehicle, and also serves as a touch surface that an occupant touches with a fingertip F or the like when switching the light on or off. The other main plane of the light-transmitting portion 13a is a light-receiving surface 13d, located opposite the light-irradiating surface 13c, that receives light irradiated from the reflector portion 12a side. The light-transmitting portion 13a also has a frame portion 13e that is continuous with the outer peripheries of the light-irradiating surface 13c and the light-receiving surface 13d.

[0022] In this embodiment, the planar shapes of the light irradiation surface 13c and the light receiving surface 13d are approximately rectangular, with two short sides along the X direction and two long sides along the Y direction. Furthermore, when the lens 13 is attached to the housing 12, the outer periphery of the light receiving surface 13d faces the lens contact surface 12d of the housing 12, and therefore the outer periphery of the lens contact surface 12d also becomes approximately rectangular to match the planar shape of the light receiving surface 13d.

[0023] The holding structure 13b is a structure for holding the bus bar 14. The holding structure 13b is an assembly of walls surrounding a third space S3, which is a space for accommodating the electrode portion 14a of the bus bar 14. The holding structure 13b has at least two walls that face each other in the X direction, namely, a first side wall 13f and a second side wall 13g. In this embodiment, the holding structure 13b includes two side walls that face each other in the Y direction in addition to the first side wall 13f and the second side wall 13g, and has a rectangular tubular shape as a whole, with the third space S3 passing through it along the Z direction.

[0024] Furthermore, the holding structure 13b is supported by the light transmitting portion 13a so that one end in the Z direction is continuous with a part of the frame portion 13e of the light transmitting portion 13a and extends along the Z direction from the light transmitting portion 13a side toward the substrate 10 side. In other words, when viewed in the Z direction, the holding structure 13b is located outside the light irradiation surface 13c and the light receiving surface 13d. In this embodiment, the holding structure 13b is supported by the light transmitting portion 13a so as to be located in the second space S2 in the housing 12 when the lens 13 is attached to the housing 12.

[0025] The first side wall 13f is a wall that faces closely to one wall that constitutes the support frame 12c of the reflector 12a when the lens 13 is attached to the housing 12. The first side wall 13f may be approximately parallel to the XZ plane, or may be inclined gradually away from the reflector 12a in the X direction as it moves away from the light-transmitting portion 13a in the Z direction. The first side wall 13f includes a first outer wall surface 13h facing the support frame 12c and a first inner wall surface 13i facing the third space S3. The first inner wall surface 13i is the surface that comes into contact with the second main plane 14d of the electrode 14a of the busbar 14 when the electrode 14a is accommodated in the third space S3.

[0026] The second side wall portion 13g is a wall portion facing the first side wall portion 13f across the third space S3. The second side wall portion 13g is approximately parallel to the XZ plane. The second side wall portion 13g includes a second inner wall surface 13j facing the third space S3 and a second outer wall surface 13k on the opposite side from the second inner wall surface 13j. The second side wall portion 13g also has two protrusions 13m protruding from the second inner wall surface 13j toward the first side wall portion 13f. When the electrode portion 14a of the bus bar 14 is accommodated in the third space S3, the protrusions 13m engage with the spring portion 14e provided on the electrode portion 14a.

[0027] Furthermore, a conductive film 30 is formed as a thin film on the light-receiving surface 13d of the light-transmitting portion 13a and the first outer wall surface 13h of the holding structure portion 13b (see FIG. 5, etc.). The conductive film 30 is preferably formed on the entire surfaces of the light-receiving surface 13d and the first outer wall surface 13h. The conductive film 30 formed on the light-receiving surface 13d and the conductive film 30 formed on the first outer wall surface 13h are continuous with each other. The conductive film 30 may be formed by coating a conductive material such as ITO (indium tin oxide) or silver nanoparticles on the surfaces of the light-receiving surface 13d and the first outer wall surface 13h. Furthermore, the conductive film 30 is not limited to a transparent material, and may be made of a so-called translucent material.

[0028] Furthermore, holding structure 13b has locking portion 13n that locks a portion of board connection portion 14b of busbar 14 when electrode portion 14a of busbar 14 is accommodated in third space S3. Locking portion 13n has a flat plate portion parallel to board 10, and by contacting a portion of board connection portion 14b on the surface facing board 10, locks the portion of board connection portion 14b so as to press it against board 10. Locking portion 13n may be reinforced by reinforcing plate 13p provided on the side opposite to the side facing board 10 to ensure rigidity.

[0029] Furthermore, the lens 13 has second protruding pieces 13r that protrude toward the console 15 along the Z direction at multiple locations on the frame portion 13e of the light-transmitting portion 13a and function as a locking mechanism when the lens 13 is attached to the housing 12. The second protruding pieces 13r are formed with second engaging holes 13s that engage with first protrusions 12g that are provided in advance on the housing 12.

[0030] 4A and 4B are perspective views of the bus bar 14. FIG. 4A is a view that allows the first main plane 14c of the electrode portion 14a to be seen. FIG. 4B is a view that allows the second main plane 14d of the electrode portion 14a to be seen. A bus bar 14 is provided for each reflector portion 12a provided in the housing 12, i.e., for each light source 20. Therefore, in this embodiment, there are two bus bars 14 that are spaced apart to match the positions of the two reflector portions 12a. The two bus bars 14 have symmetrical shapes.

[0031] Busbar 14 is a conductive metal member that contacts both lens 13 and electrode pad 21 on substrate 10. Busbar 14 may be formed by appropriately processing a thin metal plate, such as pressing, cutting, drilling, or bending. Busbar 14 has electrode portion 14a and substrate connection portion 14b, which are integrated with each other.

[0032] The electrode portion 14a is a flat portion accommodated in the third space S3 provided in the holding structure 13b of the lens 13. The planar shape of the electrode portion 14a is a substantially rectangular shape with two short sides aligned in the Z direction and two long sides aligned in the Y direction. The electrode portion 14a has a first main plane 14c, which is one of the main planes, and a second main plane 14d, which is the other main plane located opposite the first main plane 14c. As described above, the second main plane 14d comes into contact with the first inner wall surface 13i of the holding structure 13b when the electrode portion 14a is accommodated in the third space S3.

[0033] The electrode portion 14a also has multiple spring portions 14e. In this embodiment, there are two spring portions 14e aligned along the Y direction. The spring portions 14e are elastic pieces formed by processing a portion of the thin metal plate that constitutes the electrode portion 14a so that they can apply a force outward from the first main plane 14c side. When the electrode portion 14a is accommodated in the third space S3, the spring portions 14e engage with the protrusions 13m of the holding structure portion 13b while applying a biasing force thereto.

[0034] Here, the distance between the first side wall 13f and the second side wall 13g of the holding structure 13b of the lens 13 may be set to a dimension that satisfies the above-mentioned conditions for contact or engagement of the various parts when the electrode 14a is housed in the third space S3. Furthermore, it is desirable that the planar dimensions of the electrode 14a be set so that the second main plane 14d faces the conductive film 30 formed on the first outer wall surface 13h of the holding structure 13b over as wide an area as possible, with the first side wall 13f sandwiched between them.

[0035] The substrate connection portion 14b is a so-called leg portion, with a portion continuing with the electrode portion 14a and another portion contacting the electrode pad 21 on the substrate 10. The substrate connection portion 14b is formed by bending or other processing on an elongated flat plate portion, and includes a base portion 14g and a contact portion 14h. The base portion 14g is a flat plate portion with one end continuing with the electrode portion 14a and the other end continuing with the contact portion 14h, and is maintained in a position approximately parallel to the substrate 10. The contact portion 14h is a curved plate portion with a free end on the end opposite to the side continuing with the base portion 14g, and is bent so as to be convex from the base portion 14g side toward the substrate 10. A hemispherical indent 14i that directly contacts the electrode pad 21 may be formed at the top of the contact portion 14h. The indent 14i makes point contact with the electrode pad 21 and allows the contact portion 14h to slide on the electrode pad 21 when pressed against the electrode pad 21, which can be advantageous in ensuring contact reliability.

[0036] The console 15 has an opening 15d that opens in the Z direction, for example, and is a housing that houses the substrate 10, the prism 11, the housing 12, the lens 13, and the bus bar 14 through the opening 15d. The console 15 is attached to an inner wall of the vehicle compartment, etc., so that the vehicle interior lighting device 1 is installed inside the vehicle compartment. The console 15 is integrally molded from an insulating, light-impermeable synthetic resin or the like.

[0037] The console 15 also has a base structure 15a therein that includes a base on which the circuit board 10 is placed, or pins for positioning the circuit board 10 on the base. The console 15 also has second protrusions 15b at multiple locations inside the console 15 that function as a locking mechanism when the housing 12 is attached to the console 15. The console 15 also has third protrusions 15c at multiple locations on the wall of the console 15 that function as a locking mechanism when the bezel 16 is attached to the console 15.

[0038] The bezel 16 is a flat lid attached to the console 15, which houses the various components, so as to cover the storage opening 15d of the console 15. In other words, the bezel 16 is also a design component that faces the interior of the vehicle. The bezel 16 is integrally molded from an insulating, light-opaque synthetic resin or the like.

[0039] The bezel 16 also has multiple openings 16a that expose the light irradiation surfaces 13c of the lenses 13 toward the interior of the vehicle. In this embodiment, there are two lenses 13, so there are two openings 16a. The bezel 16 also has third protruding pieces 16b at multiple locations on the frame edge that protrude toward the console 15 in the Z direction and function as a locking mechanism when the housing 12 is attached to the console 15. The third protruding pieces 16b are each formed with a third engagement hole 16c that engages with a third protrusion 15c that is previously provided on the console 15.

[0040] 5 and 6 are partial cross-sectional views of the vehicle interior lighting device 1. Fig. 5 corresponds to the VV cross section in Fig. 1, and is a view taken along the XZ plane passing through the spring portion 14e of the bus bar 14 and the protrusion 13m of the holding structure 13b with which the spring portion 14e engages, with respect to the side of one lens 13. Fig. 6 corresponds to the VI-VI cross section in Fig. 1, and is a view taken along the XZ plane passing through the electrode portion 14a and the board connection portion 14b of the bus bar 14, with respect to the side of one lens 13.

[0041] In this embodiment, the bus bar 14 is attached to the holding structure 13b of the lens 13. At this time, the electrode portion 14a of the bus bar 14 is inserted into the third space S3 between the first side wall portion 13f and the second side wall portion 13g. As shown in FIG. 5, the spring portion 14e provided in advance on the electrode portion 14a engages with the protrusion portion 13m protruding from the second side wall portion 13g and applies a biasing force to the protrusion portion 13m. As a result, the second main plane 14d of the electrode portion 14a is pressed against and closely adheres to the first inner wall surface 13i of the first side wall portion 13f. Meanwhile, a conductive film 30 that forms a capacitance is formed on the first outer wall surface 13h of the first side wall portion 13f, which is opposite to the first inner wall surface 13i. That is, the second main plane 14d of the electrode portion 14a and the conductive film 30 on the first outer wall surface 13h face each other with the first side wall portion 13f interposed therebetween, and are in communication with each other.

[0042] Furthermore, when the bus bar 14 is attached to the holding structure 13b, the locking portion 13n provided in advance on the holding structure 13b comes into contact with the base portion 14g on the board connection portion 14b of the bus bar 14 near the electrode pad 21 on the board 10, as shown in FIG. 6 . Here, the housing 12 is formed in advance with a through portion 12e that penetrates between the second space S2 and the back surface side on which the board 10 is disposed. As a result, when the lens 13 with the bus bar 14 attached to the holding structure 13b is attached to the housing 12, a portion of the board connection portion 14b is exposed from the second space S2 side to the board 10 side. In this state, when the housing 12 with the lens 13 attached is assembled into the console 15, the contact portion 14h on the board connection portion 14b comes into contact with the electrode pad 21 on the board 10. The contact portion 14h is bent in advance from the base portion 14g side to the substrate 10 side so as to be convex and is continuous with the substrate connection portion 14b, so that it is constantly pressed onto the electrode pad 21 by its elastic force.

[0043] Furthermore, the electrode portion 14a is inserted into the third space S3 from the tip side opposite the side where the holding structure portion 13b is continuous with the light-transmitting portion 13a in the Z direction. In this case, after the electrode portion 14a is inserted into the third space S3, the spring portion 14e has a shape that applies a biasing force to the protrusion portion 13m from a direction roughly opposite to the insertion direction. As a result, the spring portion 14e and the base portion 14g sandwich a part of the holding structure portion 13b therebetween, so that the busbar 14 is stably supported by the holding structure portion 13b.

[0044] In addition, a conductive film 30 that is continuous with the conductive film formed on the first outer wall surface 13h of the holding structure 13b is also formed on the light receiving surface 13d of the light transmitting portion 13a of the lens 13. This makes the light irradiated surface 13c of the lens 13 a a touch surface, and a capacitive touch switch structure is configured in which the light is turned on and off when the occupant touches the light irradiated surface 13c.

[0045] In this type of capacitive touch switch structure, first, in an initial state, the light source 20 is off and the interior lighting device 1 is turned off, but the control unit 22 continues to monitor the capacitance. When an occupant in the vehicle interior touches the light-irradiated surface 13c of the lens 13 from this state, the capacitance generated between the occupant's fingertip F and the electrode portion 14a of the bus bar 14 changes. The control unit 22 then detects the change in capacitance via the board connection portion 14b of the bus bar 14 and the electrode pad 21, and switches the light source 20 on based on this detection. This causes the interior lighting device 1 to light up.

[0046] When the occupant subsequently touches the light irradiation surface 13c, the capacitance generated between the fingertip F and the electrode portion 14a changes again, and the control portion 22 detects the change in capacitance in the same manner as above and switches off the light source 20 based on the detection, thereby turning off the interior lighting device 1.

[0047] Next, the effects of the vehicle interior lighting device 1 will be described.

[0048] The vehicle interior lighting device 1 includes a light source 20, a conductive bus bar 14 having a flat electrode portion 14a, a lens 13 having a light-transmitting portion 13a that transmits light emitted from the light source 20 toward the interior of the vehicle cabin, and a holding structure 13b that holds the electrode portion 14a. The vehicle interior lighting device 1 also includes a light-transmitting conductive film 30 formed on a portion of the lens 13, and a control unit 22 that switches the light source 20 on and off in response to a change in capacitance between the electrode portion 14a and a part of a human body that touches the light-irradiating surface 13c of the light-transmitting portion 13a. The holding structure 13b has a wall that contacts a second principal plane 14d that is a principal plane of the electrode portion 14a, and is located outside the light-receiving surface 13d on the back side of the light-irradiating surface 13c when viewed in the light irradiation direction. The conductive film 30 is formed on the light-receiving surface 13d and on a first outer wall surface 13h opposite to the first inner wall surface 13i, which is the surface of the wall of the holding structure 13b that contacts the second main plane 14d of the electrode portion 14a. The conductive film 30 formed on the light-receiving surface 13d and the conductive film 30 formed on the first outer wall surface 13h are continuous with each other.

[0049] In this vehicle interior lighting device 1, the first inner wall surface 13i is located on, for example, the first side wall portion 13f, which is a wall portion included in the holding structure 13b, as part of the lens 13. Meanwhile, the second main plane 14d is located on the flat electrode portion 14a, as part of the busbar 14. The first inner wall surface 13i and the second main plane 14d are in contact with each other, so the lens 13 and the busbar 14 are physically continuous with each other. The holding structure 13b, including the portion where the first inner wall surface 13i and the second main plane 14d are in contact with each other, is located outside the light-receiving surface 13d of the light-transmitting portion 13a, as viewed in the light irradiation direction corresponding to the Z direction, as shown in FIG. 6 . That is, the busbar 14 is not located on the side opposite the light-receiving surface 13d in the Z direction, i.e., on the light-receiving surface 13d.

[0050] In the vehicle interior lighting device 1, a conductive film 30 is formed on the light-receiving surface 13d of the light-transmitting portion 13a and on the first outer wall surface 13h of the holding structure 13b, the first outer wall surface 13h being opposite the first inner wall surface 13i. The conductive film 30 formed on the light-receiving surface 13d and the conductive film 30 formed on the first outer wall surface 13h are continuous with each other. In this case, the first inner wall surface 13i and the first outer wall surface 13h are located on opposite sides of the first side wall portion 13f, and are therefore close to each other. In other words, the electrode portion 14a of the bus bar 14 in contact with the first inner wall surface 13i and the conductive film 30 formed on the first outer wall surface 13h are close to each other across the first side wall portion 13f. Therefore, even if a part of the busbar 14 is not positioned on the light receiving surface 13d, it is possible to realize a capacitive touch switch structure that maintains the capacitance detection accuracy and allows the light irradiated surface 13c to function as a touch surface that can be touched by, for example, a fingertip F as part of the human body.

[0051] Furthermore, in the vehicle interior lighting device 1, the bus bar 14 is not positioned on the side opposite the light receiving surface 13d of the light transmitting portion 13a in the Z direction, thereby improving the degree of freedom in layout regarding the first space S1 in the above example or its vicinity.

[0052] As a comparative example, consider a case where light-irradiating surface 13c is used as a touch surface, and part of the bus bar is disposed on the side opposite light-receiving surface 13d in the Z direction in order to reduce the distance between part of the human body and the bus bar. In this case, part of the bus bar is provided, for example, on back surface 12i of lens-facing portion 12j of housing 12, opposite lens contact surface 12d. Therefore, lens contact surface 12d is required to have a width sufficient to accommodate part of the bus bar, which may result in significant limitations on the shape or structure of reflector portion 12a including reflective portion 12b.

[0053] FIG. 7 is a partial cross-sectional view of the vehicle interior lighting device 1 illustrating another shape of the housing 12, corresponding to the drawing in FIG. 6. Unlike the comparative example described above, the vehicle interior lighting device 1 does not need to arrange the bus bar 14 on the back surface 12i of the lens facing portion 12j. Therefore, for example, the shape of the lens facing portion 12j of the housing 12 can be made compact as shown in FIG. 7, which reduces restrictions on the shape or structure of the reflector portion 12a and improves layout freedom. Alternatively, since the vehicle interior lighting device 1 does not need to arrange the bus bar 14 on the back surface 12i of the lens facing portion 12j, the reflector portion 12a may have a structure in which the lens facing portion 12j itself is not provided.

[0054] As described above, according to this embodiment, it is possible to provide a vehicle interior lighting device 1 that improves the degree of freedom in design.

[0055] Furthermore, in the vehicle interior lighting device 1, the holding structure 13b may have a first side wall 13f facing an optical path through which light emitted from the light source 20 passes before reaching the light-transmitting portion 13a, and a second side wall 13g facing the side opposite to the side where the first side wall 13f faces the optical path. The electrode portion 14a is held between the first side wall 13f and the second side wall 13g. The wall with which the second main plane 14d of the electrode portion 14a comes into contact is the first side wall 13f.

[0056] The first side wall portion 13f has a first inner wall surface 13i with which the second principal plane 14d of the electrode portion 14a of the busbar 14 comes into contact. According to this vehicle interior lighting device 1, the first side wall portion 13f is disposed to face the optical path along which light emitted from the light source 20 passes before reaching the light-transmitting portion 13a. Therefore, the first inner wall surface 13i, and therefore the second principal plane 14d, also face the optical path. Therefore, the holding structure 13b can hold the electrode portion 14a so that it fits into the space on the optical path side, i.e., the first space S1 in the above example. Therefore, the holding structure 13b not only holds the electrode portion 14a between the first side wall portion 13f and the second side wall portion 13g, but also allows the busbar 14 to be arranged stably and compactly within the vehicle interior lighting device 1.

[0057] Furthermore, in the vehicle interior lighting device 1, the second side wall 13g may have a protrusion 13m that protrudes toward the first side wall 13f. The electrode portion 14a may have a spring portion 14e that applies a biasing force outward from the first main flat surface 14c opposite to the second main flat surface 14d that contacts the first side wall 13f. When the electrode portion 14a is inserted between the first side wall 13f and the second side wall 13g, the spring portion 14e engages with the protrusion 13m while applying a biasing force to it.

[0058] According to this vehicle interior lighting device 1, when the electrode portion 14a is held by the holding structure 13b, the spring portion 14e applies a biasing force toward the second side wall portion 13g, so that the electrode portion 14a is pressed against the first side wall portion 13f as a whole. In other words, the second main plane 14d of the electrode portion 14a comes into close contact with the first inner wall surface 13i of the first side wall portion 13f, which can be more advantageous in terms of maintaining the accuracy of capacitance detection, for example.

[0059] The vehicle interior lighting device 1 may also include a substrate 10 on which an electrode pad 21 is mounted, which is electrically connected to the control unit 22. The bus bar 14 may have a substrate connection portion 14b formed in a shape such that a portion of the bus bar 14 is continuous with the electrode portion 14a and another portion of the bus bar 14 is in contact with the electrode pad 21.

[0060] According to this vehicle interior lighting device 1, the board connection portion 14b can be formed as shown in the above example, which can be advantageous in simplifying the shape or structure of the bus bar 14 and, in turn, the various parts related to the connection with the bus bar 14, or in reducing the number of parts that make up the vehicle interior lighting device 1.

[0061] In the above description, it is assumed that the light-transmitting portion 13a of the lens 13 is configured such that substantially the entire light-irradiating surface 13c, which serves as the touch surface, irradiates light into the vehicle interior. However, this embodiment is not limited to this configuration of the light-transmitting portion 13a. For example, the light-transmitting portion 13a may have a transmitting portion consisting of only letters or symbols, and may be configured to block light from surfaces other than the letters or symbols.

[0062] Although the present embodiment has been described above, the present embodiment is not limited to this, and various modifications are possible within the scope of the gist of the present embodiment. [Explanation of symbols]

[0063] 1 Vehicle interior lighting system 10 Substrate 13 Lens 13a Light transmitting part 13b Retaining structure 13c Light irradiation surface 13d light receiving surface 13f 1st side wall part 13g Second side wall 13h 1st outer wall surface 13m protrusion 14 Busbar 14a Electrode section 14b Board connection part 14c 1st principal plane 14d 2nd principal plane 14e Spring part 20 light source 21 Electrode pads 22 Control Unit 30 Conductive film

Claims

1. A light source and a conductive bus bar having a flat electrode portion; a lens having a light transmitting portion that transmits light emitted from the light source toward the interior of the vehicle and a holding structure that holds the electrode portion; a conductive film formed on a part of the lens and having optical transparency; a control unit that switches the light source on and off in response to a change in capacitance between the electrode unit and a part of a human body that touches the light irradiation surface of the light transmission unit, the holding structure has a wall portion that contacts a main plane of the electrode portion, and is located outside a light-receiving surface on the back side of the light-irradiated surface when viewed in the light irradiation direction, the bus bar is disposed outside the light receiving surface when viewed in the irradiation direction of the light, with the electrode portion held by the holding structure; the conductive film is formed on the light-receiving surface and an outer wall surface of the wall portion of the holding structure portion opposite to a surface with which the main plane of the electrode portion makes contact, The conductive film formed on the light receiving surface and the conductive film formed on the outer wall surface are continuous with each other.

2. the holding structure includes a first side wall portion facing an optical path through which the light emitted from the light source passes before reaching the light transmitting portion, and a second side wall portion facing the first side wall portion on an opposite side to the side facing the optical path, the electrode portion is held between the first side wall portion and the second side wall portion, The vehicle interior lighting device according to claim 1 , wherein the wall portion with which the main plane of the electrode portion is in contact is the first side wall portion.

3. the second side wall portion has a protrusion portion that protrudes toward the first side wall portion, the electrode portion has a spring portion that applies a biasing force outward from a main surface opposite to the main surface that is in contact with the first side wall portion, The vehicle interior lighting device according to claim 2 , wherein the spring portion engages with the protrusion while applying the biasing force to the protrusion when the electrode portion is inserted between the first side wall portion and the second side wall portion.

4. a substrate on which electrode pads that are electrically connected to the control unit are mounted, 4. The vehicle interior lighting device according to claim 1, wherein the bus bar has a board connection portion formed in a shape such that a part of the board connection portion is continuous with the electrode portion and another part of the board connection portion is in contact with the electrode pad.

Images