(12) United States Patent
`Hayami et al.
`
`US006293686B1
`(16) Patent N6;
`US 6,293,686 B1
`(45) Date 0f Patent:
`Sep. 25, 2001
`
`5,343,371
`5,373,424
`5,379,196
`
`,
`
`,
`
`5,614,788
`
`8/1994 Kobayahi et a1. .
`12/1994 Ishikawa.
`1/1995 KQbaYahi ct 9L -
`ghtlbatilelt 91-
`3/1997 Mullins et al. .
`
`a 0 e a .
`
`.
`
`5,645,338 * 7/1997 K b
`h' ........................... .. 362/61
`5,660,454 * 8/1997 M(())ril}gzsall. ........................... .. 362/61
`5,707,129
`1/1998 Kobayashi.
`6,049,749 * 4/2000 K b
`h' ........................... .. 701/49
`6,176,590 * 1/2001 Przvzisetlal. ....................... .. 362/37
`
`FOREIGN PATENT DOCUMENTS
`
`0 761 497 A2
`0 864 462 A1
`
`3/1997 (EP) .
`9/1998 (EP) .
`
`4 Cited by examiner
`
`Primary Examiner—Thomas M. Sember
`Assistant Examiner—Ali Alavi
`(74) Attorney, Agent, or Firm—Sughrue, Mion; Zinn;
`M ak & S
`PLLC
`acpe
`eas’
`(57)
`
`ABSTRACT
`
`.
`
`.
`
`.
`
`_
`
`_
`
`_
`
`_
`
`_
`
`The lighting device for a vehicle includes running direction
`detect means 3 for detecting the vehicle running direction or
`the vehicle steering angle and vehicle speed detect means 4
`for detecting the vehicle speed. An illumination control
`means 5 speci?es the turn-on and turn-off of a plurality of
`lamps in accordance With detect signals output from the
`means 3 and 4, thereby changing the combinations of the
`illumination ranges of the lamps.
`
`(54) LIGHTING DEVICE FOR VEHICLES
`
`(75) Inventors: Toshihisa Hayami; Hiroyuki Ishida;
`Hideki Uchida; Atsushi Sugimoto, all
`of shlzuoka (JP)
`
`~
`
`.
`.
`.
`(73) Asslgnee: K01“) Manufactunng Co" Ltd" Tokyo
`(JP)
`
`(*) Notice?
`
`Subjectto any disclaimer?heterm Ofthis
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`(21) Appl. No.: 09/507,896
`
`(22) Filed:
`
`Feb. 22, 2000
`
`Forelgn Apphcatlon Prmnty Data
`(30)
`Feb. 22, 1999
`(JP) ................................................. .. 11-43343
`
`(51) Int. Cl.7 ............................. .. B60Q 1/00; F21V 21/28
`(52) US. Cl. ........................ .. 362/465; 362/464; 362/466;
`362/276; 362/36; 362/37; 362/802; 315/81;
`
`362/36 37 43
`(58) Field of Search
`362/465, 464, 276, 49, 802; 315/81, 82;
`307/108 340/468
`’
`
`315/82; 307/108; 340/468
`
`(56)
`
`References Cited
`
`US. PATENT DOCUMENTS
`12/1974 Kondo .
`8/1990 Shirai 61 al. .
`8/1994 Ishikawa .
`
`3,855,462
`4,951,178
`5,339,226
`
`26 Claims, 8 Drawing Sheets
`
`5
`
`3 w RUNNING
`DIRECTION
`DETECT MEANS
`
`4
`“ VEHICLE SPEED
`DETECT MEANS
`
`——>
`
`_ ILLUMINATION
`' CONTROL
`MEANS
`
`6 W WEATHER
`COND ' DETECT/p
`WEATHER INFO.
`ACQUIRE MEANS
`
`1
`i
`
`24
`o A’
`
`0 ~22
`
`,
`
`'
`
`'
`
`~24
`
`SL Corp. Exhibit 1027
`
`

`
`U.S. Patent
`
`Sep. 25,2001
`
`Sheet 1 of 8
`
`US 6,293,686 B1
`
`FIG. 1
`
`3“ RUNNING
`DIRECTION
`DETECT MEANS
`
`4
`”\ VEHICLE SPEED
`DETECT MEANS
`
`——>
`
`_ ILLUMINATION
`' CONTROL
`MEANS
`
`WEATHER
`COND ' DETECT/
`WEATHER INFO.
`ACQUIRE MEANS
`
`I
`
`~24
`
`o ~2-2
`
`

`
`U.S. Patent
`
`Sep. 25,2001
`
`Sheet 2 of 8
`
`US 6,293,686 B1
`
`

`
`U.S. Patent
`
`Sep.
`25, 2001
`
`Sheet 3 of 8
`
`US 6,293,686 B1
`
`

`
`U.S. Patent
`
`Sep. 25,2001
`
`Sheet 4 of 8
`
`US 6,293,686 B1
`
`Fl 5
`
`“I
`
`B(ADVANCING DIRECTION)
`
`23a
`
`FIG. 6
`
`II
`\
`
`L
`
`B(ADVANC|NG DIRECTION)
`
`/ 0a
`
`24a
`
`24b
`
`L 6'
`
`L'
`
`

`
`U.S. Patent
`
`Sep. 25,2001
`
`Sheet 5 of 8
`
`US 6,293,686 B1
`
`FIG. 7
`
`25
`
`24a
`
`24b
`
`24b
`
`

`
`U.S. Patent
`
`Sep. 25,2001
`
`Sheet 6 6f 8
`
`US 6,293,686 B1
`
`FIG. 9
`B(ADVANC|NG DIRECTION)
`
`127
`
`FIG. 10
`B(ADVANC|NG DIRECTION)
`
`127
`
`

`
`U.S. Patent
`
`Sep. 25, 2001
`
`Sheet 7 of 8
`
`US 6,293,686 B1
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`
`U.S. Patent
`
`Sep. 25,2001
`
`Sheet 8 of 8
`
`US 6,293,686 B1
`
`FIG. 12
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`V
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`
`US 6,293,686 B1
`
`1
`LIGHTING DEVICE FOR VEHICLES
`
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`The present invention relates to a lighting device disposed
`in the front portion of a vehicle in the advancing direction of
`the vehicle and including a plurality of lamps and, in
`particular, to a lighting device having a structure that
`changes combinations of illumination ranges provided by
`the plurality of lamps, thereby specifying the control of the
`light distribution.
`2. Description of the Related Art
`Conventionally, there is knoWn a device Which detects the
`steering angle of a vehicle to change the illumination
`direction of a lamp according to variations in the detected
`steering angle. Such a device enhances vehicle safety, espe
`cially When driving through curves at night.
`Although the conventional device is generally though. to
`be acceptable, it is not Without shortcomings. In particular,
`the conventional device eXerts control over illumination
`direction only When the vehicle travels through a curve. That
`is, the direction of part of an illumination light is changed
`successively according to the steering angle When the
`vehicle runs in the curve. Therefore, the conventional device
`does not su?iciently illuminate a road sign, a pedestrian, a
`preceding vehicle, an oncoming vehicle, an obstacle or the
`like.
`
`SUMMARY OF THE INVENTION
`
`In vieW of the above, it is an object of the invention to
`provide a lighting device Which changes the combinations of
`illumination ranges provided by a plurality of lamps accord
`ing to not only the running direction or steering angle of a
`vehicle, but also the speed of the vehicle to thereby control
`direction and range of illumination so to maintain constant
`light distribution control, Which is proper for the vehicle’s
`running condition.
`In order to achieve the objectives, the present lighting
`device for a vehicle includes a plurality of lamps disposed in
`the front portion of the vehicle in the advancing direction
`thereof. The lighting device has running direction detect
`means for detecting the running direction or steering angle
`of the vehicle, vehicle speed detect means for detecting the
`speed of the vehicle, and illumination control means for
`specifying the turn-on or turn-off of the plurality of lamps in
`accordance With detect signals output from the running
`direction detect means and vehicle speed detect means to
`change the combinations of the illumination ranges of the
`lamps, thereby controlling the light distribution of the light
`ing device in front of the vehicle as Well as laterally of the
`vehicle.
`The combinations of the illumination ranges of the lamps
`are changed according to the running direction or steering
`angle of the vehicle and according to the vehicle speed to
`thereby control the direction and range of the illumination of
`the lighting device, so that the light distribution of the
`lighting device in front of the vehicle can be speci?ed.
`
`15
`
`25
`
`35
`
`45
`
`55
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a block diagram of a lighting device for a vehicle
`according to an embodiment of the present invention;
`FIG. 2, together With FIGS. 3 to 14, shoW a lighting
`device for a vehicle according to an embodiment of the
`present invention; and, in particular, FIG. 2 is a schematic
`
`65
`
`2
`vieW of the lamps of the lighting device arranged in the front
`portion of a vehicle;
`FIG. 3 is a schematic vieW of the illumination ranges of
`the respective lamps When vieWed from above the vehicle;
`FIG. 4 is a perspective vieW of an eXample of the structure
`of a head lamp employed in the lighting device;
`FIG. 5, together With FIGS. 6 to 10, shoW an eXample of
`the structure of another lamp (other than the head lamp); in
`particular, FIG. 5 is a schematic vieW of a lamp Which is
`composed of tWo illuminating portions;
`FIG. 6 is a schematic vieW of an eXample of a lamp
`composed of tWo illuminating portions, each including a
`re?ecting portion formed in a paraboloid of revolution;
`FIG. 7, together With FIG. 8, schematically shoW a lamp
`structured such that the optical aXis of its re?ecting portion
`faces in a desired direction by rotating part of a re?ecting
`mirror about a given aXis; and, in particular, FIG. 7 shoWs
`an eXample of such lamp in Which the rotation center aXis of
`its re?ecting portion 24a is formed of a vertical aXis passing
`through the light emitting center point LC of a light source;
`FIG. 8 shoWs an eXample of such lamp in Which the
`rotation center aXis of its re?ecting portion 24a is formed of
`a vertical aXis passing through a point RC located behind the
`light emitting center point LC of the light source;
`FIG. 9, together With FIG. 10, shoW an eXample of the
`structure of a lamp having a function to control its light
`distribution in a variable manner; and, in particular, FIG. 9
`shoWs a state of the lamp in Which the respective optical
`aXes of its ?xed and movable re?ecting mirrors both face
`forWardly of the vehicle;
`FIG. 10 shoWs a state of the lamp in Which its movable
`re?ecting mirror is speci?ed in a direction inclined With
`respect to a vehicle advancing direction B;
`FIG. 11 shoWs tWo tables for explaining the examples of
`control over the respective lamps;
`FIG. 12, together With FIGS. 13 and 14, eXplain the light
`distribution patterns of a head lamp; and, in particular, FIG.
`12 is a schematic vieW of a light distribution pattern in a city
`area running mode and in a suburbs running mode While a
`sub-beam is on;
`FIG. 13 is a schemata, vieW of a light distribution pattern
`in high-speed running mode While the sub-beam is on; and
`FIG. 14 is a schematic vieW of another light distribution
`pattern While the sub-beam is on.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`FIG. 1 shoWs the basic structure of a lighting device for
`a vehicle 1 according to an embodiment of the present
`invention. The lighting device for a vehicle 1 includes a
`plurality of lamps 2-i (i=1, 2, .
`.
`disposed in the front
`portion of the vehicle in the advancing direction of the
`vehicle. The lighting device 1 combines together the illu
`mination ranges of tWo or more of the lamps to control or
`change the light distribution of the lighting device 1. The
`lamps may include a head lamp, a cornering lamp, a rain
`lamp, a fog lamp, a bending lamp, and other similar lamps.
`The lighting device for a vehicle 1 also includes running
`direction detect means 3 for detecting the running direction
`of a vehicle or the steering angle thereof, and vehicle speed
`detect means 4 for detecting the speed of the vehicle. The
`detected information is transmitted to illumination control
`means 5, Which is disposed doWnstream of the running
`direction detect means 3 and the vehicle speed detect means
`4.
`
`

`
`US 6,293,686 B1
`
`3
`The running direction detect means 3 may be, for
`example, a detect sensor for detecting a steering angle (such
`as the operation angle of a steering Wheel or the like) and/or
`a detect sensor for detecting an instruction signal to a
`direction indicator. Also, the running direction detect means
`3 may determine the current and folloWing running direction
`of the vehicle based on road map information, including the
`shapes of a road and the current vehicle position informa
`tion. Such information can be obtained, for example, from a
`navigation (route guide) system using a GPS (Global Posi
`tioning System) satellite, and a road-and-vehicle vehicle
`communication system (a system using facilities for con
`nected a vehicle and a road by radio communication).
`The vehicle speed detect means 4 may be, for example, a
`speed sensor equipped in the vehicle.
`The illumination control means 5 turns the plurality of
`lamps 2-i (i=1, 2, .
`.
`on or off according to the signals
`received from the running direction detect means 3 and the
`vehicle speed detect means 4, thereby changing the combi
`nations of the illumination ranges of the lamps. In this Way,
`the illumination control means 5 controls the light distribu
`tion in front of and/or laterally of the vehicle. The illumi
`nation control means 5 sends signals to the respective lamps
`for turning them on or off.
`For example, as the vehicle speed detected by the vehicle
`speed detect means 4 increases, the illumination control
`means 5 decreases the number of lamps to be turned on,
`thereby narroWing the illumination range of the lighting
`device. Accordingly, When the vehicle runs at a high speed,
`the illumination range provided by the lamps does not move
`right and left greatly, even if the steering angle of the
`steering Wheel of the vehicle is changed by steering the
`steering Wheel. Thus, the light distribution of the lighting
`device is stabiliZed, Which makes it possible to prevent the
`illumination of the lamps from alarming road users (such as
`the drivers of other vehicles) and to prevent the glare of the
`lamps from daZZling the road users.
`When the straight running of the vehicle is detected by the
`running direction detect means 3, the illumination control
`means 5 turns on only the lamps facing and illuminating in
`the advancing direction of the vehicle. When a variation in
`the running direction of the vehicle or in the steering angle
`is detected by the running direction detect means 3, the
`illumination control means turns on additional lamps. As the
`running direction variation increases, additional lamps are
`turned on one by one so that the lamps illuminate a Wider
`range of area in a turning action of the vehicle. The illumi
`nation control means 5 turns on or off the respective lamps
`in stages, such that in right and left: turns, as Well as in the
`curved road running, the lighting device 1 illuminates a
`direction Where the vehicle is going to curve and also a Wide
`range including such direction, Which provides an advantage
`that a suf?cient ?eld of vision can be secured in front of a
`driver.
`Typically, the vehicle’s running environment varies
`depending on time and place. Preferably, therefore, the
`lighting device 1 includes Weather condition detect or
`Weather information acquire means 6 (see FIG. 1), Which
`determine the Weather condition in an area Where the vehicle
`is running. When the illumination control means 5 receives
`a signal from ID the Weather condition detect or Weather
`information acquire means 6, and judges that the Weather is
`inclement, the illumination control means 5 turns on the
`lamps for illuminating the lines on the road or the shoulder
`of the road. In this Way, during inclement Weather (such as
`rainy Weather, cloudy Weather, snoWy Weather, foggy
`
`15
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`25
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`35
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`45
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`55
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`65
`
`4
`Weather, and the like), the lines on the road (such as a center
`line and the rain mark of the shoulder) remain visually
`con?rmable to a driver.
`The Weather situation may be detected using tWo meth
`ods. One method detects the Weather situation directly, and
`the other method detects the Weather situation indirectly, i.e.,
`the Weather situation is pieced out from various kinds of
`indirect information. The direct method uses an image
`processing technique based on information obtained by a
`front photographing camera, or various sensors for respec
`tively detecting raindrops, temperature and humidity, and
`peripheral illuminance, and the Weather situation is detected
`synthetically according to various kinds of information from
`the sensors. On the other hand, the indirect method, for
`example, uses various kinds of information from devices
`such as a Windshield Wipers and the like that are operated in
`accordance With variations in the Weather, that is, the
`operation signal of the Wiper, and a signal shoWing the
`condition of the Wiper. By the Way, the Weather information
`can also be acquired by using the above-described road-to
`road communication, an FM multiple communication and
`other similar communication.
`The illumination range of the lighting device may be
`controlled by a mechanism for causing the illuminating
`directions of the lamps to vary. For example, each of the
`lamps may include a drive mechanism for adjusting optical
`members forming the lamp, such as a re?ecting mirror, a
`light shield member, and a lens. The illuminating directions
`of the lamps are variably controlled by signals that are
`applied from outside. HoWever, if the illuminating range of
`the lighting device in front of and laterally of a vehicle is
`divided into a plurality of blocks, and if lamps differing in
`the illuminating direction from one another are used to
`illuminate their respective blocks individually to thereby
`specify the Whole illuminating range of the lighting device,
`then the respective lamps can be structured in a simple
`manner (the light distributions of the respective lamps may
`remain ?xed.), Which provides an advantage that not only
`the number of parts but also the cost of the lighting device
`are reduced.
`The lighting device 1 may include, for example, (1) a
`main lamp for illuminating the vehicle advancing direction
`(front direction), (2) a subordinate lamp for illuminating the
`lines on the road or the shoulder of the road, (3) a laterally
`illuminating lamp having an illuminating range extending
`from obliquely forWardly of the vehicle to laterally of the
`vehicle, and (4) an auxiliary lamp having an illuminating
`range extending betWeen the illuminating range of the
`subordinate lamp and the illuminating range of the laterally
`illuminating lamp. These lamps illuminate a sufficient range
`in the ?eld of vieW from the vehicle. In a car, for example,
`a head lamp corresponds to the main lamp, a rain lamp
`corresponds to the subordinate lamp, a cornering lamp
`corresponds to the laterally illuminating lamp, and a bending
`lamp corresponds to the auxiliary lamp. Preferably, in the
`front portion of a vehicle, the laterally illuminating lamp and
`the auxiliary lamp are arranged beloW the main and subor
`dinate lamps.
`The illumination control means 5 sends turn-on and
`turn-off signals to the lamps in a stage by stage manner. Such
`stage by stage control may cause part of the illumination
`range to suddenly brighten or darken. Preferably, therefore,
`lamps having overlapping (or contiguous) illumination
`ranges are turned on and off gradually. For example, When
`turning on (turning off) a second lamp after a ?rst lamp is
`turned on (turned off), the light quantity of the second lamp
`is gradually increased (decreased) according to variations in
`
`

`
`US 6,293,686 B1
`
`5
`the running direction of the vehicle or in the steering angle.
`Accordingly the brightness of the lamps are allowed to vary
`stage by stage or continuously in accordance With control
`signals from the illumination control means 5 to the respec
`tive lamps 2-i. For this purpose, for example, the light
`sources of the lamps (such as an incandescent lamp or a
`discharge lamp) may be controlled via electric currents,
`voltages, or supply poWers.
`EMBODIMENT
`FIGS. 2 to 4 shoW an embodiment of the present invention
`applied to a lighting device for a car. An arrangement of
`lamps are mounted on one corner (left side corner) of the car.
`The lamps include a head lamp 7, a rain lamp 8, a bending
`lamp 9, and a cornering lamp 10.
`The head lamp 7 is positioned rather near to the side
`portion of the vehicle front portion, While the rain lamp 8 is
`arranged at a position Which is lateral of and in front of the
`head lamp 7. The bending lamp 9 is situated beloW the rain
`lamp 8, and the cornering lamp 10 is arranged in the side
`surface portion of the vehicle and beloW the head lamp 7.
`The lamps function as folloWs. The head lamp 7 plays a
`major role in distributing the light of a passing beam or a
`running beam. The rain lamp 8 is a combination lamp in that
`it illuminates the corners of the road and illuminates in the
`rainy Weather. The bending lamp 9 illuminates the corners of
`the road When the vehicle runs at loW speeds. The cornering
`lamp 10 illuminates the road at an intersection.
`In the present embodiment, as Will be discussed later, the
`head lamp’s light distribution is variably controlled. On the
`other hand, the remaining lamps have light distributions that
`are ?xed.
`FIG. 3 schematically shoWs the illumination ranges of the
`lamps of the lighting device, When vieWed from above.
`Areas A7, A7
`the illumination ranges of the left and
`right head lamps 7. The head lamps 7 illuminate farthest in
`front of the vehicle, and have respective optical axes that are
`movable in the horiZontal direction (see arroW marks shoWn
`in FIG. 3) in a given angular range, for example, in the range
`of —5° (left) to +5° (right). That is, as shoWn by broken lines
`in FIG. 3, the head lamp 7 on the right has an optical axis
`that is moveable to the right; and, the head lamp 7 on the left
`has an optical axis that is moveable to the left. Preferably,
`the optical axes are moved according to the variations in the
`steering angle caused by the operation of a steering Wheel.
`Areas A8, A8 indicate the illumination ranges of the right
`and left rain lamps 8, Which illuminate the surface of the
`road that is nearer to the vehicle than the road surface
`illuminated by the head lamps 7. Speci?cally, the rain lamp
`8 arranged in the front and left portion of the vehicle, Where
`the Road Traffic LaW speci?es that vehicles keep to the left,
`illuminate a White line about 20 m (meters) ahead of a
`vehicle line side, Whereas the rain lamp 8 arranged in the
`front and right portion of the vehicle illuminates a center line
`and a White line draWn on the road shoulder under the
`condition that its glare does not give a daZZling light to an
`oncoming vehicle.
`Areas A10, A10 indicate the illumination ranges of the
`right and left cornering lamps 10, Which extend from the
`obliquely forWard direction of the vehicle (an angular direc
`tion of about 45° With respect to the advancing direction of
`the vehicle) to the lateral side of the vehicle (an angular
`direction of about 90° With respect to the advancing direc
`tion of the vehicle).
`Areas A9, A9 indicate the illumination ranges of the right
`and left bending lamps 9, Which cover the ranges that are
`situated betWeen the areas A8, and A10.
`
`10
`
`15
`
`35
`
`45
`
`55
`
`65
`
`6
`As shoWn in FIG. 3, When all of the lamps are turned on,
`they illuminate a Wide range in front of the vehicle.
`Next, With reference to FIGS. 4 to 10, a description Will
`be given of the examples of the lamp structures.
`FIG. 4 shoWs a head lamp 7 of a projector type, Which
`includes a projection lens 11, a shade 12, and a re?ecting
`mirror 13. The head lamp also includes a drive mechanism
`to change the attitudes of the shade 12 and the re?ecting
`mirror 13. Accordingly, the height (upper limit position) of
`the lamp’s light distribution pattern is changeable, and the
`lamp’s optical axis is moveable in the right and left direc
`tions.
`The shade 12 includes a cylindrical portion 12a that
`speci?es the height (upper limit position) of the light dis
`tribution pattern on its oWn vehicle side, and a cylindrical
`portion 12b that speci?es the height (upper limit position) of
`the light distribution pattern on the oncoming vehicle side.
`TWo rotary shafts 14, 14 (only one of them is shoWn) are
`disposed at positions eccentric With respect to the centers of
`the tWo cylindrical portions 12a, 12b. The tWo rotary shafts
`project laterally from their respective cylindrical portions,
`and are respectively rotated by their associated actuators
`15,16. Thus, the respective heights of the tWo cylindrical
`portions can be speci?ed. As shoWn in FIG. 14, the light
`distribution pattern is projected as the inverted image of the
`shade 12.
`The head lamp 7 also includes a light source 17 mounted
`on the re?ecting mirror 13. The light emitting portion of the
`light source 17 is situated on the optical axis of the re?ecting
`mirror 13, Within a recessed portion formed in the re?ecting
`mirror 13. The re?ecting mirror 13 may include a re?ecting
`surface such as an elliptic-parabolic re?ecting surface, or an
`ellipsoid of revolution.
`The lamp 7 also includes a drive mechanism, for driving
`the re?ecting mirror 13, in Which an upper portion of the
`re?ecting mirror 3 is mounted through tWo parallel links 18,
`18 on a support member 19. The re?ecting mirror 13 is
`rotatable in a direction shoWn by an arroW mark R (FIG. 4)
`by an L-shaped rotary link 21. The L-shaped rotary link 21
`extends from an actuator 20 ?xed to the support member 19
`to the peripheral edge portion of the re?ecting mirror 13.
`This drive mechanism shifts the optical axis of the re?ecting
`mirror 13 in the right and left direction. Accordingly, the
`illuminating direction of the lamp can be turned to a desired
`direction.
`FIGS. 5 to 10 shoW examples of lamps, other than the
`head lamp 7. Namely, FIGS. 5—10 shoW the rain lamp 8,
`bending lamp 9, and cornering lamp 10, Which have a
`general structure When used in a lighting device for a car.
`That is, these lamps include a lens, a re?ecting mirror, and
`a light source. These lamps also have a ?xed light
`distribution, as opposed to the variable light distribution
`described With respect to the head lamp 7. The light distri
`bution may be decided by cooperative optical operation of a
`lens step disposed in the lens and the re?ecting mirror; or,
`the lens may be composed of a plain-glass lens, or the lens
`may be formed in an almost plain-glass state and only a
`small lens step may be formed in the lens, While most of the
`light distribution may be speci?ed only by the design of the
`shape of the re?ecting mirror.
`FIG. 5 is a horiZontal section vieW of a lamp 22 (other
`than the head lamp 7) that is arranged on the left side of the
`front portion of the vehicle. The lamp 22, Which includes a
`lens 23, a re?ecting mirror 24 and a light source 25, is
`divided to tWo illuminating portions 22a and 22b by a
`vertical surface containing the main light axis K-K of the
`
`

`
`US 6,293,686 B1
`
`7
`lamp 22. That is, the illuminating portion 22a includes a lens
`portion 23a and a re?ecting portion 24a. These tWo portions
`23a, 24a cooperate, such that the light emitted from the light
`source 25 (arroW mark G) illuminates in a forWard and left
`oblique direction With respect to the advancing direction of
`the vehicle. On other hand, the illuminating portion 22b
`includes a lens portion 23b and a re?ecting portion 24b.
`These tWo portions 23b, 24b cooperate, such that the light
`emitted from the light source 25 (arroW mark I) illuminates
`in a direction substantially parallel to the advancing direc
`tion of the vehicle. By the Way, the illuminating directions
`G, I of the illuminating portions 22a, 22b depend on hoW the
`optical axes of the respective re?ecting portions 24a, 24b are
`set. That is, the optical axis of the re?ecting portion 24a is
`set in parallel to the arroW mark G, While the optical axis of
`the re?ecting portion 24b is set in parallel to the arroW mark
`
`FIG. 6 shoWs an example in Which the re?ecting surface
`of the re?ecting portion 24b is formed in a paraboloid of
`revolution, and its axis of rotational symmetry, that is, an
`optical axis L-L is de?ned so as to extend along the
`advancing direction B of the vehicle (see 1b at a point P).
`The re?ecting surface of the re?ecting portion 24a is formed
`in a paraboloid of revolution, and its axis of rotational
`symmetry, that is, an optical axis L‘-L‘ is inclined at an angle
`of 6 With respect to the optical axis L-L (see la at a point Q).
`Also, a re?ecting mirror may have a part that is rotatable
`about a given axis to thereby turn the optical axis to a desired
`direction. For example, as shoWn in FIG. 7, the rotational
`center axis of the re?ecting portion 24a coincides With a
`vertical axis Which passes through the light emitting center
`point LC of the light source 25 and extends in a direction
`perpendicular to the sheet surface of FIG. 7. In another
`example, as shoWn in FIG. 8, the rotational center axis of the
`re?ecting portion 24a coincides With a vertical axis Which
`passes through a point RC located behind the light emitting
`center point LC of the light source 25. In both examples, the
`re?ecting portion 24b remains ?xed, While the re?ecting
`portion 24a has a variable (or adjustable) attitude. The
`attitude of the re?ecting portion 24a is varied by drive means
`such as an actuator to thereby illumination light in a desired
`direction.
`By the Way, in the rain lamp 8, bending lamp 9 and
`cornering lamp 10, as Well as in the head lamp 7, there may
`be employed a structure Which has a function to control the
`light distribution of the lamp in a variable manner. Such a
`structure is shoWn, for example, in FIGS. 9 and 10.
`FIGS. 9 and 10 shoW horiZontal section vieWs of a lamp
`having a lamp body 26 and a lens 27 for covering the
`opening of the lamp body 26. The lamp body 26 and the lens
`27 de?ne a lamp space in Which a ?xed re?ecting mirror 28
`is disposed. A movable re?ecting mirror 29 is disposed
`inside the ?xed re?ecting mirror 28. The moveable re?ecting
`mirror 29 has a rotational center axis that passes through the
`light emitting center of a light source 30 and extends
`perpendicular to the sheet surface of FIG. 9 or FIG. 10. The
`movable re?ecting mirror 29 is coupled to an actuator 31
`through a link member 32. Accordingly, the actuator may
`rotate the moveable re?ecting mirror 29 to obtain different
`types of light distributions. For example, as shoWn in FIG.
`9, the optical axes of the re?ecting surface 28a of the ?xed
`re?ecting mirror 28 and the re?ecting surface 29a of the
`movable re?ecting mirror 29 both extend in the vehicle
`advancing direction (arroW mark B). But as shoWn in FIG.
`10, the optical axis of the re?ecting surface 29a is speci?ed
`in a direction inclined With respect to the vehicle advancing
`direction B because the movable re?ecting mirror 29 is
`rotated at a desired angle by the actuator 31.
`
`15
`
`25
`
`35
`
`45
`
`55
`
`65
`
`8
`In addition, drive means, for driving optical members
`(such as an inner lens and a shade), may be disposed Within
`a lamp to control the light distribution of the lamp. Such
`techniques are convenient in that they realiZe the functions
`of a plurality of lamps in a single lamp. For example, a single
`lamp, Which is capable of controlling its light distribution,
`may perform the functions of a bending lamp and a corner
`ing lamp.
`Next, a description Will be given of the relationship
`betWeen illumination the illumination control modes and the
`illumination states of the respective lamps.
`In the present embodiment, the illumination control is
`divided to the folloWing modes:
`(i) City area running mode;
`(ii) Suburbs running mode; and
`(iii) High-speed running mode.
`is for a relatively loW
`The city area running mode
`speed running operation, Which makes it possible to recog
`niZe a road user such as a pedestrian. The city area running
`mode
`has the folloWing illuminating objects:
`a) Illuminate in front of the vehicle up to a brake distance
`at a running speed (exactly, the sum of an idle running
`distance and a brake distance, for example, about 20 m at 40
`km/h).
`b) enable con?rmation of an oncoming vehicle line and a
`side Walk on its oWn vehicle line side suf?ciently When
`running in a tWo-lane roadWay.
`The suburbs running mode (ii) makes it possible to
`con?rm an obstacle and the curb in a middle-speed running
`operation. This mode has the folloWing objects.
`a) Illuminate in front of the vehicle up to a brake distance
`at a running speed (for example, about 75 m at 80 km/h).
`b) Secure an illumination range of a given Width (about 6
`m to 10 m) With oWn vehicle as a reference in a tWo-lane
`roadWay.
`The high-speed running mode (iii) is for a vehicle running
`operation at a high speed of 80 km/h or more. This mode has
`the folloWing objects:
`a) AlloW recognition of objects fallen onto the ground and
`illuminate in front of the vehicle up to a fallen object
`avoidable distance (for example, about 110
`b) Avoid giving a leading vehicle a daZZling light (for
`example, the illumination of the light onto the door mirror
`of the leading vehicle).
`FIG. 11 shoWs tWo tables Which set forth the cont