Abstract: A lighting apparatus for a vehicle cab or cabin, having a plurality of reading lights for a plurality of passenger seats. A number of the reading lights is at least equal to the number of passenger seats, and a mean distance between the reading lights is less than a shortest possible distance between the passenger seats.

Abstract: An in-vehicle illuminating device capable of preventing light emitted from a light source from coming directly into a passenger's sight. An in-vehicle illuminating device 1 includes a housing 2, a reflective member 18 provided within the housing 2, a light source or LEDs 10 orienting a light axis of light emitted therefrom to the reflective member 18. Reflected light obtained by allowing the reflective member 18 to reflect the light emitted from the LEDs 40 is irradiated to the outside of the housing 2, thus preventing light emitted from the LEDs 40 from coming directly into a passenger's sight.

Abstract: A vehicular light assembly (10) is held in an operative position within a liner (12) by an intermediate retainer (32) which has spring-like tongues (42). The retainer (32) is held in position on the liner (12) by fixation tabs (36) which are bent through the receiving hole (18) and pinch the liner (12) against a mounting plate (34) of the retainer (32). Segmented shoulders (46) on a sidewall (20) of the light assembly (10) are received in channels (48) on each of the tongues (42) and seat above the tips (44) of each tongue (42) to retain the light assembly (10) in its operative position. By simple application of a manual force, a service person is able to install or remove the light assembly (10) from its operative position in the liner (12). Thus, no tools are required to install or service the light assembly (10). Furthermore, the intermediate retainer (32) functions as a single unit to interconnect the liner (12) and the light assembly (10).

Abstract: An onboard interior lighting system includes: a functional section main body 11 including functional part attachment portions 11a, 11b and an electric wire connecting part PA connecting electric wires Wa; an electric wire protecting cover 1 configured to cover the electric wire connecting part after the electric wires are connected to the electric wire connecting part; and a functional section A arranged on an exterior side of a ceiling board of a vehicle. The functional section main body is one selected from a selection group for which a plurality of mutually-different types of functional section main bodies are provided, the electric wire protecting cover 1 is of only a single type provided commonly for the mutually-different types of functional section main bodies. The electric wire connecting part PA of each type of functional section main body has its common locking counterparts corresponding to the respective lock parts of the electric wire protecting cover 1 of the single type.

Abstract: A vehicle interior light system includes a lamp, an enclosure internally provided with the lamp, a lens attached to the front of the enclosure, a touch sensor arranged on the back surface of the lens, and a control circuit including a sensor circuit and a switching circuit. The sensor circuit is configured to detect the capacitance of a human body when the lens is touched or approached by a finger or the like. The switching circuit is configured to turn the lamp on and off in response to an output from the sensor circuit.

Abstract: A lamp assembly includes a bezel having a lamp receiving section and an integrated attachment section. The integrated attachment section has one or more outwardly directed extensions for attaching the lamp assembly to the interior component by rotating the bezel into a receiving aperture. A lamp housing is disposed within the lamp receiving assembly. Finally, the lamp assembly includes a light source positioned within the lamp housing for projecting light along a light path.

Abstract: A vehicle interior illumination lamp unit includes: a designed unit disposed on a lower side of a ceiling plate of a vehicle; and a functional unit disposed on an upper side of the ceiling plate of the vehicle and coupled to the designed unit. A spacer insertion space is provided on an outside of an operation plate of the functional unit, and an insertion plate portion of the spacer is inserted into the spacer insertion space, whereby engagement between an engagement hook and an engaged portion is inhibited from being released by an impact.

Abstract: There is provided a vehicle interior illumination system wherein a linear illumination unit having an elongated linear illuminating portion which extends in a longitudinal direction of a vehicle passenger compartment ceiling is provided along each of left- and right-hand edges of the vehicle passenger compartment ceiling and light emitted from the linear illuminating portion directly illuminates the vehicle passenger compartment.

Abstract: A room lamp which is cost effective and simple. The room lamp has a design part and a function part, the design part being secured with a lens in a housing attachable to an opening defined in an interior finish material of a vehicle, and the function part being disposed at a side of a rear face of the interior finish material in that the function part is supported by the design part, and having a light source. Clips are provided in the housing for temporarily securing the design part at predetermined positions. Projections project from the edge part of the opening along the rear face of the interior finish material. The housing and the projections hold the interior finish material.

Abstract: Interior lighting and illumination systems for aircraft, particularly commercial passenger airplanes. Opposing pairs of LED lamps are positioned in the ceiling panels above the aisles between sets of seats in the passenger cabins. One set of LED lights are directed to illuminate the ceiling panels and may be in a particular color. The other set of LED lights are positioned to shine their lights on storage/stowage bins positioned across the aisles, thus creating a cross-bin lighting system. This enhances the cabin architecture and provides cabin illumination. A reflector can be positioned to direct the light and reduce possible glare to the passengers. The reflector directs the light rays from the LED lights which emanate from the top of the reflector to shine on the lowest part of the bins. The light rays leaving the reflector cross in front of the reflector.

Abstract: An interior lamp is provided for illuminating an interior of a vehicle having a glass surface, particularly a glass roof. At least one such interior lamp is integrated in the laminated glass of the glass surface.

Abstract: An illumination device includes a first light source. The first light source is fixed on an interior ceiling located between a driver seat and a passenger seat in a vehicle. The first light source illuminates an interior compartment of the vehicle. The illumination device also includes a second light source that illuminates around the driver or the passenger. The illumination device further includes a switch that electrically controls the second light source. The switch includes a peripheral part that is located adjacent to the first light source, and the peripheral part emits light from the first light source. The illumination device indicates a location of the switch in dark conditions in the interior compartment of the vehicle in a visually pleasing manner. The illumination device has a simple structure and is simple to install.

Abstract: A lighting assembly includes a bezel, a housing coupled to the bezel, the housing having a pivot point provided on a first surface, a lamp provided between the housing and the bezel, and a biasing member configured to bias the lamp against the bezel. The biasing member engages the housing at the pivot point, and the lamp pivots relative to the housing about the pivot point.

Abstract: The present invention is to provide a better design, and a uniform and bright lighting to a cover lens. A lamp holder holds a lamp L and a lamp bezel holds the lamp holder. The lamp bezel is attached to a roof of a vehicle. The cover lens covers a front side of the lamp bezel and the lamp holder. A part of the cover lens is embossed so as that the lamp holder is hardly visible through the cover lens from a front side of the cover lens. The part is thinly embossed as approaching to a periphery of the part in order to increase a light transmittance.

Abstract: A console device for a vehicle includes a housing body fixed by a side face to the ceiling part of the vehicle. The device has a recessed part formed by an opening in another side face, and a cover body that pivots on the housing body. The recessed part can be closed by moving the cover body into place over the recessed part of the housing body. A storage portion formed on the surface of the cover body opposite the recessed part allows small articles to be stored inside it and removed from it only when the recessed part is opened. An illumination portion that radiates light to the inside of the vehicle cabin is formed on another surface of the cover body.

Abstract: An opening is formed through a roof trim of a vehicle, and a design part of an interior illumination lamp is mounted in this opening. Self-holding-purpose retaining lock piece portions are formed integrally on an opposite surface of a lens which forms part of the design part. A light shielding layer is formed on those portions of the lens corresponding respectively to the retaining lock piece portions.

Abstract: The invention relates to overhead console projector lamp optics, and more particularly, optics for an overhead console projector lamp for the interior of a vehicle. An overhead console projector lamp for the interior of a vehicle can include at least one projector lamp set, a light source, and a reflector. The projector lamp set includes at least one projector lamp that includes a converging lens. The overhead console projector lamp can be configured to produce a narrow beam of light that can be focused on an object in the interior of the vehicle.

Abstract: A method for controlling the intensity of light within an interior passenger compartment in a motor vehicle to create perceived sensations of safety, comfort and personal accommodation in conjunction with specified, night time, driving-related occurrences. The natural human desire for safety is satisfied as a driver approaches a parked motor vehicle by illuminating the interior passenger compartment with a plurality of light sources (18, 20, 22) in response to having produced a safety approach signal. The natural human desire to be comfortable within a confined space is satisfied by the act of opening the door (28), whereupon the interior illumination intensity is automatically lowered to a second intensity level. Once the transmission shift selector is moved out of its Park condition, the interior light intensity is automatically decreased to a third intensity level to provide the sensation of stress reduction and thus satisfy the natural human desire to be at peace.

Abstract: A LED swivel reading lamp having an easily user adjustable sized light beam for use in vehicles such as automobiles, aircraft, and the like.

Abstract: An interchangeable flashlight-cargo lamp system includes a docking station that is suitable for mounting either a cargo lamp or a rechargeable flashlight. The flashlight doubles as a cargo lamp when mounted within the docking station. Both the cargo lamp and the flashlight have common mounting elements that mate with corresponding mounting features of the docking station to permit either device to be inserted into and removed from the docking station. The interchangeable devices also include electrical contacts that mate with corresponding electrical contacts in the docking station. The flashlight further includes a battery that is recharged when the flashlight is mounted in the docking station.

Abstract: A lamp unit mounting structure includes a mounting panel having a mounting portion, a lamp unit, an elastic fixing member and a restricting member. The elastic fixing member is provided on the lamp unit, and includes a first portion which is extended from the lamp unit, a second portion which has a substantially U-shape, and has a first end being integrally connected to the first portion, a third portion which is extended from a second end of the second portion toward the lamp unit. The engagement portion engages the mounting portion of the mounting panel. The restricting member is provided on the lamp unit, and restricts a movement of the elastic fixing member in a mounting and dismounting direction of the engagement portion relative to the mounting panel. The restricting member has an escape portion which allows a movement of the elastic fixing member toward the lamp unit.

Abstract: To provide an interior illuminator for an automobile that prevents light leakage to the driver's seat and light reflection in a window glass, can illuminate a backseat more evenly with an adequate quantity of light, consumes less electric power, generates less heat, has a small size and can be produced at a reduced cost. An interior illuminator has: cold cathode tubes 5, 6; a cold cathode tube driving circuit for driving the cold cathode tubes 5, 6; manipulation switches 12, 13, 14 and 15 for turning on and off the cold cathode tubes; and a housing 2 that houses the cold cathode tube driving circuit and holds the cold cathode tubes and the manipulation switches. The housing 2 is attached in a position on a longitudinal center line of the automobile and behind the driver's seat, and the cold cathode tubes 5, 6 each have an illumination range set to be lower than the lower edge of a window glass behind the driver's seat.

Abstract: A cold cathode fluorescent lamp lighting device includes a lens cover, a cold cathode fluorescent lamp and a control box. The lens cover is a semicircular-shaped tube and includes a post having a threaded hole for insertion of a bolt. The cold cathode fluorescent lamp is circular and secured in the lens cover. The control box includes a control circuit to control the lighting of the cold cathode fluorescent lamp. The control box further comprises electric wires and a connector to be connected with a connector of the cold cathode fluorescent lamp.

Abstract: The invention relates to a moonroof for a motor vehicle, the moonroof comprising a transparent wedge-shaped essentially solid body having a surface that is to be turned toward an interior space of a motor vehicle, and having a surface opposite the surface that is to be turned toward the interior space of the motor vehicle, the surface that is to be turned toward the interior space of the motor vehicle being inclined to the surface opposite the surface to be turned toward the interior space of the motor vehicle and the moonroof comprising a light source for introducing light into the transparent wedge-shaped essentially solid body.

Abstract: Dual function console lighting with integrated switching includes a lamp housing held by a retainer within a bezel secured to a vehicle interior. The lamp housing includes eccentrically positioned collinear pivot arms relative to a central longitudinal axis of a lamp positioned within the housing. The pivot arms engage the retainer to hold the lamp housing within the retainer while allowing the lamp housing to pivot relative to the plane of the retainer. The retainer is rotatably held within the bezel by a plurality of snap features spaced around its circumference, allowing the lamp housing and retainer to rotate. A latching mechanism holds the lamp housing in a retracted position with a lens of the housing preferably substantially flush relative to immediately surrounding portions of the bezel. A spring provides a force to pivot the housing about the pivot arms to a second position when the latch is released.

Abstract: A system for displaying images includes: (a) a base; (b) a movable, arcuate-shaped receptacle that rotates into and from the base; and (c) a display attached to the receptacle so that the display is visible when the receptacle is rotated from the base and the display is partially or entirely not visible when the receptacle is rotated into the base.

Abstract: An adjustable light beam device for an aimable vehicle lamp assembly is provided. The adjustable light beam device includes a lamp housing having a channel member with an outer portion and an inner portion. A tube component is positioned within the interior portion of the channel member. The tube component is adjustably movable along the inner portion of the channel member.

Abstract: A vehicle lamp assembly comprised of: a heat sink with at least one flange extending beyond the lamp assembly; a circuit board functionally engaging the inner surface of the heat sink and having a power supply circuitry; at least one light emitting unit electrically connected to the heat sink; a potting compound substantially imbedding the circuit board and corresponding electrical connections; and a lens operatively attached to the heat sink. In one embodiment, the light emitting unit is an LED. In alternate embodiments, the lamp assembly can include fins and/or fans to further facilitate cooling of the assembly, and/or a reflective inner surface of the heat sink to increase the lamp assembly's luminous output.

Abstract: The procedure consists in incorporating in the actual process of conforming a roof lining, determined by the securing to each other of a previously conformed lining support and the positioning and securing thereon of a coating, of one or more electroluminescent strips which will constitute a lighting system of the roof lining, which electroluminescent strips are integrated between such lining support and coating, each of them with a ribbon cable and a connector which are made to pass through a hole of the support of the lining and is finished in a connector, which is hidden by the rear face of the actual lining for its connection to the power supply of the roof of the vehicle in which the lining is applied.

Abstract: A vehicle room lamp includes a box-like body, a light source received within the box-like body, a switch provided within the box-like body so as to control the turning-on and -off of the light source, a light-transmitting portion which is provided at the box-like body at an opening thereof so as to move toward and away from the switch, and allows light from the light source to pass therethrough to the exterior of the box-like body, and an abutment member which is movable together with the light-transmitting portion, and can operate the switch in accordance with the movement of the light-transmitting portion toward the switch. The abutment member is disposed outside a light distribution range of light directed from the light source toward the light-transmitting portion.

Abstract: A lighting assembly (10) is adjustable between flood and spot lighting conditions for selectively illuminating an interior passenger compartment in a motor vehicle. The assembly (10) includes a housing (16) which clamps to a supporting member, such as a headliner (12), via a sleeve (18) interacting with a rotary cam lock (22). An LED light source (26) is orbitally supported within the housing (16) for projecting light in a directionally adjustable manner. A lens (50) is disposed in the light path (28) and is moveable between an extended spot position for task lighting and a retracted flood position for general illumination within the interior compartment. A switch (74) is responsive to movement of the lens (50) into its spot position for automatically energizing the LED (30). The switch (74) opens, thus de-energizing the LED (30) when the lens (50) is returned to its flood condition.

Abstract: A phototherapy device suitable for shining light on a vehicle driver (3) in order to suppress melatonin production and increase wakefulness, having at least one light fixture (1) located in the region of the head of the driver (3), is improved in terms of its freedom front glare, with undiminished effectiveness, in that the light fixture (1) is embodied to emit essentially nondirectional diffuse light (7) and is located outside the field of view of the driver (3), or at least in the peripheral region of his field of view.

Abstract: An interior illumination lamp includes a body 30 for being fixed to a vehicle body 11, and a lamp 50 which is angularly movably supported on a support portion 33 mounted on the body 30, and has a lens 54 capable of transmitting a beam from a light source 37 therethrough. The lamp 50 includes a first bezel 52 angularly movably supported on the support portion 33, and a second bezel 53 which holds the lens 54, and is mounted on the first bezel 52. The second bezel 53 has a reflecting surface 55 for receiving and reflecting transmitted light through the lens 54, and this reflecting surface is designed to have a low reflectance. By doing so, the light, reflected by the reflecting surface 55, is not glaring, and therefore a beam, coming into the driver's sight via a room mirror, is not glaring, and therefore will not affect the driving operation.

Abstract: A design part 20 is attached to an aperture 12 provided in an interior material 11 of a automobile, and a functional part 30 is arranged at the rear side of the interior material 11 supported by the design part 20. A switching unit 32 feeding and cutting an electric power to a light source 31 is configured as a separate body attached to a functional main body 30a in such a manner that switch units 32 of different mechanisms can be selectively attached to the functional main body 30a. Thus, since the functional main body 30a is used in common even when the switching unit 32 is changed and has a general-purpose nature, cost reduction can be attained.

Abstract: To guide a passenger to the general location of his assigned seat in an aircraft cabin, the cabin is divided into several cabin zones that are individually identified by different colors of illumination, for example a yellow cabin zone, a red cabin zone and a blue cabin zone. Each service class can correspond to one cabin zone or encompass plural cabin zones. Lighting devices arranged in the cabin are activated to provide illuminating light having the appropriate allocated illumination color in each respective cabin zone. The lighting devices are preferably ceiling lights, sidewall lights, and/or window funnel lights, controlled from a flight attendant panel via a lighting controller. A passenger ticket displays the passenger's assigned seat number and letter, and also the color of the cabin zone in which the assigned seat is located.

Abstract: The invention is to provide an interior illumination lamp which can change lighting directions, not directly touching lenses by the fingers. If rotating fins in the forward direction of the lenses, outer bezels are rotated together, so that a light emitting direction can be adjusted, not directly contacting the lenses with the fingers as conventionally. Even if the lenses are heated, the light emitting directions can be adjusted thereby. Not directly contacting the lenses by the fingers, the lenses are prevented from being stained to decrease illumination. In addition, since the fins avoid the light diffusion, a driver and other riding people are kept off dazzling by the light.

Abstract: A full function light bar is provided mountable inside a vehicle against the windshield. The light bar is an assembly of several light sources, including strobe lamps, flashing lamps, oscillating lamps, and an aimable take down lamp. The light bar is not limited in application to one specific vehicular model and is adaptable and adjustable to conform to the windshield, rear window, or other interior cab surfaces of varying shape (curvature). The light sources are supported on a flexible support mount which has adjustable, flexible gaskets. End caps and the gaskets screen the inside of the vehicle from the light emitted by the light bar. The support mount is hung on adjustable brackets which allow the light bar to be raised, lowered and tilted to further facilitate conformance with the windshield.

Abstract: An automobile roof grip and light includes a grip body and a light. The grip body has an elongate chamber in an intermediate portion, an elongate chamber hole formed in an inner sidewall, and a hole bored in one end of the chamber. An elongate cap closes on the chamber hole. The light device is deposited in the chamber, consisting of an elongate circuit board and plural LED on the circuit board. Then the grip and light can be used both as a grip and a light to be lit up for increasing brightness and also usable as a warning of showing a door being not yet closed.

Abstract: A self-luminous road sign system comprises a plurality of sensor units 1 . . . 1 each of which is equipped at least with a visibility meter and an illuminance meter, or which may be equipped with an anemovane and a thermometer as well as the visibility meter and the illuminance meter; and an information processing and management department 2 for centralized management of weather information detected by the plural sensor units in order to predict any danger in the road observation area, wherein the output information from the information processing and management department 2 is displayed on road installations 4 . . . 4 connected via a network. Based on the road background brightness obtained by the illuminance meter in the sensor unit, the optimum luminous brightness which provides a predetermined contrast is calculated.

Abstract: A lighting device is provided for illuminating the trunk of a motor vehicle having a retractable roof which can be stowed in the trunk. The retractable roof includes a front roof element and a rear roof element which can be moved between a position in which the roof elements cover the vehicle and a position in which the roof elements are stored in the trunk. At least one of the roof elements is provided with a lighting device for illuminating the passenger compartment when the roof is covering the vehicle. Detectors are provided for detecting when the roof is folded-up and stowed in the trunk and when the trunk lid of the vehicle is opened. The detectors are connected to a controller so that the lighting device is illuminated when the roof is folded-up in the trunk and the trunk lid is at the same time opened.

Abstract: A lighting fixture frame and mounting panel apparatus that includes a frame formed with an interior wall circumscribing a central opening and a panel for mounting a lighting device. The frame is formed with inwardly projecting stop pads and resilient legs formed with inwardly projecting teeth, and the panel is received upwardly into the central opening until it is securely mounted in a panel slot formed between the lower surfaces of the pads and the upper surfaces of the teeth.

Abstract: The invention is directed to provide a vehicle interior illumination device which has a high illuminating effect and which can be used for various kinds of illumination in a vehicle. The illumination device disposed in a roof portion of the interior of a vehicle, including: a first light-emitting section having a first light source constituted by a plurality of first LEDs disposed at substantially regular spaces; and a second light-emitting section having a second light source constituted by a second LED, and a second outer lens with which a light emission side of the second light source is covered and by which light emitted from said second light source is converged and radiated out.

Abstract: An interior lighting system for a motor vehicle includes a lighting device configured to light a motor vehicle interior and a control unit configured to regulate the brightness and/or the color of the light emitted from the lighting device. The color of the light emitted from the lighting device may be automatically adjusted in accordance with at least one operating parameter and/or at least one parameter associated with the environment of the motor vehicle. Such parameters include, for example, a deviation of an actual temperature from a predetermined desired temperature of the motor vehicle interior and/or the driving speed of the vehicle.

Abstract: A lighting fixture frame and mounting panel apparatus that includes a frame formed with an interior wall circumscribing a central opening and a panel for mounting a lighting device. The frame is formed with inwardly projecting stop pads and resilient legs formed with inwardly projecting teeth, and the panel is received upwardly into the central opening until it is securely mounted in a panel slot formed between the lower surfaces of the pads and the upper surfaces of the teeth.

Abstract: A console lighting assembly is provided for illuminating an interior of a vehicle comprising a housing assembly mounted in the interior of a vehicle passenger compartment. A plurality of pulleys are positioned in the housing assembly, each of the plurality of pulleys is individually rotatable. A plurality of illumination units each includes a respective cable and a light generator at a distal end of the cable. Each cable is spooled on a respective pulley and the illumination units are movable between a retracted position and an extended position. A plurality of switch pads are located on the housing assembly and are positioned around the plurality of illumination units for activating and deactivating a respective illumination unit. A retractor is coupled to the pulleys for retracting the plurality of illumination units from the extended position to the retracted position. Each of the plurality of illumination units is pliable so as to maintain a selected orientation of illumination as determined by a user.

Abstract: The present invention relates to a light-guiding system for improving the lighting conditions of the passenger compartment of a motor vehicle, including a light-generating unit (3) which can be switched on and off electrically and a light guide (5) which is used for guiding the light and which is coupled to the light-generating unit (3) for coupling in the light. According to the present invention, the light guide (5) is arranged in the area of the interior lining of the vehicle roof (1) and designed as a flat light guide, the light being coupled in at one or more lateral surfaces (7, 8) of the light guide (5); and the flat light guide (5) being prepared such that the light couples out of the light guide (5) into the passenger compartment (2) of the vehicle over a large surface and in a homogeneous manner.

Abstract: An inclined engagement surface of an elastic engagement hook is elastically engaged with an engaged section in a state of being inclined with respect to a roof panel. As a result, it is possible to absorb an error of a three-dimensional relative positional relation between the elastic engagement hook and the engaged section. That is, the error of the relative positional relation in two directions (an X direction and a Y direction in FIG. 5B) can be absorbed by a deflection of the inclined engagement surface, and the error of the relative positional relation in remaining one direction (a Z direction in FIG. 5B) can be absorbed by a slip between the inclined engagement surface and the engaged section.

Abstract: An interior illuminating apparatus for a vehicle includes an interior rear-view minor which is connected and fixed to an interior ceiling of the vehicle for observing the rear. An LED is provided in a vicinity of the interior rear-view mirror at a forward position in a traveling direction of the vehicle and radiates ultraviolet light on a center part of an instrument panel. An operating unit adapted to receive the ultraviolet light from the LED is provided in the center part of the instrument panel. The apparatus includes a starting switch for actuating the LED on and off. The operating unit has fluorescent layers coated thereon and containing a substance which emits fluorescence when irradiated with the ultraviolet light from the LED.

Abstract: The invention is directed to provide a vehicle interior illumination device which has a high illuminating effect and which can be used for various kinds of illumination in a vehicle. The illumination device disposed in a roof portion of the interior of a vehicle, including: a first light-emitting section having a first light source constituted by a plurality of first LEDs disposed at substantially regular spaces; and a second light-emitting section having a second light source constituted by a second LED, and a second outer lens with which a light emission side of the second light source is covered and by which light emitted from said second light source is converged and radiated out.

Abstract: A self-luminous road sign system comprises a plurality of sensor units 1 . . . 1 each of which is equipped at least with a visibility meter and an illuminance meter, or which may be equipped with an anemovane and a thermometer as well as the visibility meter and the illuminance meter; and an information processing and management department 2 for centralized management of weather information detected by the plural sensor units in order to predict any danger in the road observation area, wherein the output information from the information processing and management department 2 is displayed on road installations 4 . . . 4 connected via a network. Based on the road background brightness obtained by the illuminance meter in the sensor unit, the optimum luminous brightness which provides a predetermined contrast is calculated.