United States Patent r19i
`Gotou
`
`[54] HEAD LAMP DEVICE FOR VEHICLE
`
`[75]
`
`Inventor: Shinichirou Gotou, Saitama-ken, Japan
`
`[73] Assignee: Honda Giken Kogyo Kabushiki
`Kaisha, Tokyo, Japan
`
`[21] Appl. No.: 472,225
`
`[22] Filed:
`
`Jun. 7, 1995
`
`[30]
`
`Foreign Application Priority Data
`
`Jan. 17, 1995
`
`[JP]
`
`Japan .................................... 7-020898
`
`Int. CI.6
`...•••••.....••...................................•.... B60Q 1/12
`[51]
`[52] U.S. CI . ................................. 362/37; 362/66; 362/40;
`315/79; 315/82
`[58] Field of Search ................................ 362171, 66, 285,
`362/287, 37, 43, 83.3, 40, 41, 36; 315/79,
`80, 81, 82; 307110.1, 10.8
`
`[56]
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`4,858,080
`4,868,720
`4,870,545
`4,891,559
`4,908,560
`5,099,400
`5,158,352
`
`8/1989 Oikawa ................................. 362171 X
`9/1989 Miyauchi et al ..................... 362171 X
`911989 Hatanaka et al .......................... 362/72
`1/1990 Matsumoto et al. ...................... 362171
`3/1990 Shibata et al. ............................ 362171
`3/1992 Lee ........................................ 362171 X
`10/1992 Ikegami et al ............................ 362171
`
`FOREIGN PATENT DOCUMENTS
`
`4/1987
`62-77249
`2296550 1211990
`
`Japan .
`Japan .
`
`I lllll llllllll Ill lllll lllll lllll lllll lllll 111111111111111111111111111111111
`US005588733A
`[l lJ Patent Number:
`[45] Date of Patent:
`
`5,588,733
`Dec. 31, 1996
`
`Primary Examiner-Ira S. Lazarus
`Assistant Examiner-Thomas M. Sember
`Attorney, Agent, or Firm-Weiner, Carrier & Burt, P.C.;
`Joseph P. Carrier; Irving M. Weiner
`[57]
`ABSTRACT
`
`A head lamp device for a vehicle in which a lighting region
`in front of the vehicle in a traveling direction can be adjusted
`in rightward and leftward directions comprises: a direction
`indicating signal outputting mechanism 11 for detecting an
`operation of a winker device and outputting a direction
`indicating signal; a steering signal outputting mechanism 12
`for detecting a steering angle .of a steering device and
`outputting a steering angle signal; a map information out(cid:173)
`putting mechanism 30 for outputting map information
`including road data; a present position detecting mechanism
`32 for detecting a present position of proper vehicle on the
`map; and a control mechanism 10 for inputting the said
`direction indicating signal, steering angle, map information
`and information of the present position and adjusting the
`lighting region of the head lamp. The control mechanism 10
`selects a first control mode when the direction indicating
`signal is outputted; a second control mode for adjusting the
`lighting region in response to the steering angle when the
`first mode is not selected and the present position is not
`found on the road data of the map information or a steering
`angle of the steering angle signal exceeds a predetermined
`range; and a third control mode for adjusting the lighting
`region in compliance with an expectation of forward road
`shape in a vehicle traveling direction in reference to the map
`information and the present position when the first and
`second control modes are not selected.
`
`17 Claims, 7 Drawing Sheets
`
`11
`
`12
`
`13
`
`Turn switch
`
`Steering angle sensor
`
`Vehicle speed sensor
`
`7
`
`10
`
`Light nistrioution
`control
`ECU
`
`14
`
`Motor driver
`
`8
`
`Left side Motor
`
`8
`
`Right side Motor
`
`34
`
`36
`
`i
`
`r-·-·-·-·-·-·-·-·-·-· ·-·-·-·-·-·-· -·-·---·-·-·-·-a1·-·-·-·-·-·-·-·-·1
`Navigation system
`i
`I
`E cu
`--------------1
`Present position 'V : 32
`detectrng part
`'
`I
`~~~--,,.~'~~
`
`GPS receiver
`
`Gyro sensor
`
`J
`j
`j
`i
`i
`Map information
`i
`35
`33
`30----i
`outputting device
`l-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·J
`NAVIGATION SYSTEM
`
`Display
`
`PCNA Ex. 1012
`U.S. Patent 11,208,029
`
`

`

`U.S. Patent
`F I G. 1
`
`Dec. 31, 1996
`
`Sheet 1of7
`
`5,588,733
`
`L L
`
`A-------' 3
`
`3
`
`2
`
`F I G. ~
`
`2~
`
`10
`
`7
`
`

`

`FIG. 3
`
`11 - i Turn switch
`
`12 ----I Steering angle sensor
`
`13
`
`--I Vehicle speed sensor
`
`r--------------------
`
`34
`
`GPS receiver
`
`Gyro sensor
`
`I
`
`JI
`
`I
`•
`I
`Map information
`.
`30----f
`!
`35
`outputting device
`.
`I
`L-----·-----------------------------·-----·-----------·----------------~
`NAVIGATION SYSTEM
`
`33
`
`I
`
`10
`
`14
`
`Light distribution
`control
`E CU
`
`Motor driver 1 - - - - 1
`
`8
`
`Left side Motor
`
`8
`
`Right
`
`side Motor
`
`'
`- - - ·. --~31·---·------------,
`·-·---·---·-·--, ---
`Navigation system
`E CU
`--------------, I
`Present position 'v 32
`
`36
`
`Display
`
`detecting part
`
`1
`
`I
`I
`
`d •
`00
`•
`~
`~ ,....
`~ = ,....
`
`~
`~
`~
`~
`!""
`~
`~
`~
`O'I
`
`rri =(cid:173)~
`~
`N
`Q
`
`"'""
`....:J
`
`Ul
`-.
`Ul
`00
`00
`-.
`
`'I w w
`
`

`

`U.S. Patent
`
`FIG.~
`
`Dec. 31, 1996
`
`Sheet 3 of 7
`
`5,588,733
`
`Light distribution
`control routine
`
`S1 Vehicle information inputted
`
`$~ Map information inputted
`
`y
`
`y
`
`$1 Q Optical axis angle e
`determined by 1ap
`information cooperating
`control map
`
`S9
`Optical axis angle
`e determined by
`steering angle
`cooperating
`control map
`
`SS
`Optical axis angle
`e determined by
`direction indication
`cooperating
`control 11ap
`
`S11 Light distribution controlled
`at optical axis angleO
`
`Return
`
`

`

`U.S. Patent
`FIG. J
`
`Dec. 31, 1996
`
`Sheet 4 of 7
`
`5,588,733
`
`Optical axis
`angle e
`Right
`
`Vehicle speed:
`V1 < V2 < V3
`
`FIG. 6
`
`Left
`
`Optical axis
`angle a
`Right
`
`Vehicle speed:
`V1 < V2 < V3
`
`Left
`
`

`

`U.S. Patent
`
`Dec. 31, 1996
`
`Sheet 5 of 7
`
`5,588,733
`
`FIG. 1
`
`maxi----
`
`S (m)
`
`a (deg)
`----min
`
`(Good)
`
`Navigation accuracy
`
`(Bad)
`
`

`

`U.S. Patent
`U.S. Patent
`F I G. ~
`FIG. 8
`
`Dec. 31, 1996
`Dec. 31, 1996
`
`Sheet 6 of 7
`Sheet 6 of 7
`
`5,588,733
`5,588,733
`
`3
`
`3
`
`
`
`F I G. ~
`
`3
`
`

`

`U.S. Patent
`U.S. Patent
`
`Dec. 31, 1996
`Dec. 31, 1996
`
`Sheet 7 of 7
`Sheet 7 of 7
`
`5,588,733
`5,588,733
`
`F I G . 1 ~
`FIG. 1ES
`
`
`
`

`

`5,588,733
`
`1
`HEAD LAMP DEVICE FOR VEHICLE
`
`BACKGROUND OF THE INVENTION
`
`5
`
`10
`
`1. Field of Invention
`This invention relates to a head lamp device for a vehicle,
`and more particularly, controlling of a lighting region of the
`head lamp in a horizontal direction.
`2. Discussion of Relevant Art
`The head lamp of a vehicle is in general operated to form
`the two different lighting regions of high-beam and low(cid:173)
`beam by manual changing-over of them.
`Variation oflamp optical axes between the high-beam and
`low-beam is directed in a vertical direction and the lamp
`optical axes are not changed in a horizontal rightward or
`leftward direction. However, when the vehicle runs along a
`curved comer or turns right or left, if the lamp optical axes
`arc moved in a turning direction to deflect the lighting
`region, visibility is improved.
`In view of the foregoing, there are many proposals in the
`prior art in which the lamp optical axes are controlled for
`their movements in the horizontal rightward or leftward
`direction in response to a steering angle of the steering wheel
`(for example, a gazette of Japanese Patent Laid-Open No. 25
`Sho 62-77249 (1987) or the like). However, the lighting
`region in such a prior art as above is not changed unless the
`steering wheel is operated, so that a turning direction can not
`be lighted at a stage before entering the curved part.
`As an example of solving this problem under a combi(cid:173)
`nation with a navigation system, there is provided a system
`described in Japanese Patent Laid-Open No. Hei 2-296550
`(1990).
`This prior art example improves visibility more by a
`method wherein a curved part or the like is foreseen in
`advance in reference to both map information of the navi(cid:173)
`gation system and information of the proper or subject
`vehicle position on the map, and the lighting region is
`changed before entering the curved part.
`However, in the case that the vehicle runs on a place
`where no road data is present, there is a possibility that
`information in a navigation system is not helpful, or the
`vehicle can not be controlled or a control timing becomes
`unstable when the vehicle turns out of a planned course at a
`crossing point or the like.
`It may also be feared that a timing of control to change the
`lighting region is not adequate for a certain vehicle speed.
`
`2
`device and outputting a steering angle signal; map informa(cid:173)
`tion outputting means for outputting map information
`including road data; present position detecting means for
`detecting a present position of a proper vehicle on the map
`information; and control means for inputting said direction
`indicating signal, steering angle signal, map information and
`information of the present position and adjusting the lighting
`region of said head lamp. Said control means selects a first
`control mode when said direction indicating signal is input-
`ted; a second control mode for adjusting the lighting region
`in response to said steering angle when said first mode is not
`selected and said present position is not found on the road
`data of said map information or a steering angle of said
`steering angle signal exceeds a predetermined range; and a
`third control mode for adjusting the lighting region in
`compliance with an expectation of a forward road shape in
`reference to said map information and the present position
`when said first and second control modes are not selected.
`When the direction indicating signal is not generated and
`20 a vehicle runs normally on the road data of the map
`information, the lighting region is adjusted in compliance
`with a road shape in the front of the vehicle expected from
`the map information and the present position under a third
`control mode, so that the lighting region is changed fast in
`advance toward a turning direction the driver wants and then
`a superior visibility can be attained.
`In addition, in the case that a vehicle runs on a place
`where no road data is found or a steering angle exceeds a
`predetermined range, a lighting region is adjusted in
`30 response to the steering angle under a second control mode,
`so that the controlling operation can be continued.
`In the case that the direction indicating signal is generated
`and a steering angle of the steering signal is within a
`predetermined range, the lighting region is changed to a
`35 predetermined region in the steering direction under the
`aforesaid first control mode, and subsequently when the
`steering angle exceeding the predetermined range is input(cid:173)
`ted, the lighting region is controlled to be changed in
`response to the steering angle under the second control
`40 mode. Namely, when the winker device is operated, at first,
`the lighting region is changed to the predetermined region in
`the steering direction by one action so as to enable a turning
`direction to be visually confirmed early, and then after the
`steering angle is determined to have exceeded the predeter-
`45 mined range, the lighting region is changed in response to
`the steering angle. Thus the changing timing of the lighting
`region can be set properly and the visibility can be
`improved.
`There may additionally be provided a vehicle speed signal
`outputting means for detecting a vehicle speed and output(cid:173)
`ting a vehicle speed signal. In this case, the control means
`changes at least one of an adjusting amount and an adjusting
`period of the lighting region in response to a vehicle speed
`55 of the vehicle speed signal under at least one of the first,
`second and third control modes, thereby a change of the
`lighting region which is most suitable for the vehicle speed
`can be carried out and the visibility can be improved more.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`15
`
`SUMMARY OF THE INVENTION
`
`50
`
`The present invention has been accomplished in view of
`the foregoing and it is an object of the present invention to
`provide a head lamp device for a vehicle in which adjust(cid:173)
`ment of the lighting region is properly carried out and a
`superior visibility can be attained even in the case that a
`vehicle runs on a place having no road information in a
`navigation system or the vehicle turns out of the planned
`course.
`In order to accomplish the aforesaid object, the present 60
`invention provides a head lamp device for a vehicle in which
`a lighting region in front of the vehicle can be adjusted in
`rightward and leftward directions characterized in that the
`device comprises direction indicating signal outputting
`means for detecting an operation of a winker device and 65
`outputting a direction indicating signal; steering signal out(cid:173)
`putting means for detecting a steering angle of a steering
`
`FIG. 1 is a view for showing a vehicle of one preferred
`embodiment of the present invention as viewed from above;
`FIG. 2 is a schematic perspective view for showing an
`swinging mechanism for a head light of the preferred
`embodiment;
`FIG. 3 is a block diagram for showing a light distribution
`control system of the preferred embodiment;
`
`

`

`5,588,733
`
`3
`FIG. 4 is a flow chart for showing a procedure of the light
`distribution control;
`FIG. 5 is a view for showing a coordinate expression of
`a direction indicating cooperating control map;
`FIG. 6 is a view for showing a coordinate expression of 5
`a steering angle cooperating control map;
`FIG. 7 is a view for showing a coordinate expression of
`a map so as to determine a control timing at a map
`information cooperating control mode;
`FIG. 8 is a view for showing a lighting region as viewed
`from above when a forward part is a linear advancing road;
`FIG. 9 is a view for showing a lighting region as viewed
`from above when a forward part is curved; and
`FIG. 10 is a view for showing a lighting region as viewed 15
`from above when there is a crossing point in a forward part.
`
`10
`
`The motor 8 is controlled for its driving by a light
`distributing control ECU 10.
`A schematic block diagram for a control system of the
`preferred embodiment is illustrated in FIG. 3 and the control 50
`system will be described.
`This vehicle 1 has a navigation system 30 mounted
`thereon, the light distributing control ECU 10 gets map
`information and information of a proper vehicle position
`from the navigation system 30 and at the same time a 55
`direction indicating signal from a tum switch 11 which is
`turned on or off under an operation of a winker lever, a
`steering angle signal from a steering angle sensor 12 for
`detecting a direction of the steering wheel and a vehicle
`speed signal from a vehicle speed sensor 13 for detecting a 60
`vehicle speed or the like are inputted to the light distribution
`control ECU 10. The ECU 10 processes the informations
`and signals to determine a requisite optical axis angle 8, and
`an indicating signal is outputted to a motor driver 14 so as
`to achieve the optical axis angle 8, and thereby the right and 65
`left motors 8 and 8 are controlled in driving with the motor
`driver 14.
`
`25
`
`30
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENT
`
`Referring now to FIGS. 1 to 10, one preferred embodi(cid:173)
`ment of the present invention will be described as follows.
`A vehicle 1 of the preferred embodiment has head lights
`2 for lighting the space in front of the vehicle installed such
`that they are swingable in a rightward or leftward horizontal
`direction. FIG. 1 is a view for showing the vehicle 1 from
`above and in this figure, the right and left head lights 2 and
`2 are swung leftward so as to cause the left forward regions
`to become lighting regions 3 and 3.
`The right and left head lights 2 and 2 are swung together
`in the same direction by the same angle and as shown in FIG.
`1, angles of their optical axes L and L with respect to an
`advancing direction of the vehicle, i.e. optical axis angles,
`are both set to be 8.
`An swinging mechanism for swinging the head lights 2 in
`the preferred embodiment is schematically shown in FIG. 2,
`wherein a lamp unit 4 of the head light 2 is fixed to a rotary
`shaft 5, and a worm gear 7 formed at a driving shaft of a
`motor 8 is engaged with a worm wheel 6 fitted to the rotary
`shaft 5.
`Accordingly, the lamp unit 4 is swung together with the
`rotary shaft 5 through an engagement between the worm
`gear 7 and the worm wheel 6 under a driving of the motor
`8.
`
`4
`The navigation system 30 will be described in brief,
`wherein a navigation system ECU 31 acting as a control
`center is operated such that a present position detecting part
`32 receives detecting signals from a gyro-sensor 33 and the
`vehicle speed sensor 13, calculates a moving position,
`obtains a position of the proper vehicle, performs a map
`matching, and at the same time performs a correction of the
`position of the proper vehicle with a position of the proper
`vehicle calculated from a satellite electric wave received
`from a GPS receiver 34 so as to detect an accurate position
`of the proper vehicle.
`The position of the proper vehicle calculated in this way
`is displayed at a display 36 together with the road data
`outputted by a map information outputting device 35.
`At the navigation system 30, many predetermined points
`(nodes) which can be searched in sequence along a road are
`set.
`Spacings between the nodes set along the road on the map
`are different at a certain location, and normally the spacings
`20 between the nodes are wide at a linear road portion, the
`spacing at a curved road portion is set to be narrow and the
`nodes are set at crossing points without fail.
`Various kinds of road information on the map, for
`example, degrees of curves or the like on the road are stored
`in correspondence with each of the nodes.
`In addition, the navigation system 30 calculates the short(cid:173)
`est path to a destination point and has a path guiding
`function for guiding the vehicle along the path.
`Referring to a flow chart of FIG. 4, a procedure of light
`distributing control to be controlled in response to the
`control system above will be described as follows.
`At first, vehicle information such as the state of the tum
`switch 11, a steering angle detected by the steering angle
`35 sensor 12 and a vehicle speed detected by the vehicle speed
`sensor 13 or the like are inputted (step 1). Then the map
`information in the navigation system 30, i.e. such as infor(cid:173)
`mation stored for every required node as crossing points,
`directions of the curves or degrees of sharpness of curves,
`40 ect., is inputted (step 2).
`Then, the operation proceeds to the step 3 to discriminate
`presence or non-presence of output of a direction indicating
`signal, and when the presence of the outputs judged, the
`operation jumps to the step 8 to enter a direction indicating
`45 cooperating control mode which is the first control mode. At
`the step 8, an optical axis angle 8 is determined in response
`to a direction indicating cooperating control map, and at the
`step 11 the motor 8 is controlled in such a way that the light
`is distributed at the determined optical axis angle 8.
`FIG. 5 shows the direction indicating cooperating control
`map by means of coordinates.
`That is, when the winker lever is operated to generate a
`direction indicating signal, the direction of the optical axis
`angle 8 is determined in response to either the turning right
`or turning left indication and then a constant predetermined
`angle is determined in response to the vehicle speed.
`As described above, when the winker lever is operated,
`the optical axis angle is changed at once to a predetermined
`angle for lighting the turning direction of the vehicle early,
`and the determined optical axis angle is larger as the vehicle
`speed is faster. Thus the angular direction that a driver may
`want to get as a visual confirmation is properly lighted so
`that a superior visibility can be attained.
`Although the optical axis angle determined just after the
`operation of the winker lever is maintained while the steer(cid:173)
`ing angle a is less than or equal to a predetermined angle,
`
`

`

`5,588,733
`
`5
`if the angle a exceeds the predetermined angle, the optical
`axis angle 8 is also made larger by controlling it in propor(cid:173)
`tion to the steering angle a so as to coincide with the state
`of to the curve.
`In addition, when the steering angle a is increased more 5
`than a certain value, the optical axis angle is fixed at a
`specified value.
`The foregoing is the direction indicating cooperating
`control mode when the direction indicating signal is gener(cid:173)
`ated and the operation jumps from the step 3 to the step 8. 10
`In the case that the direction indicating signal is not gener(cid:173)
`ated, the operation advances from the step 3 to the step 4,
`and it is discriminated whether or not the proper vehicle runs
`on the road data in reference to the map information and the
`present position of the proper vehicle. In the case that the 15
`proper vehicle does not run on the road data, i.e. the vehicle
`runs on a place where no road data is found, the operation
`jumps to the step 9 and enters the steering angle cooperating
`control mode which is the second control mode. When the
`vehicle runs on the road data, the operation advances to the 20
`step 5 and it is discriminated whether or not the steering
`angle a is within a predetermined range.
`This predetermined range is a range of the steering angle
`expected to be applied in the vicinity of the curve entrance
`which is determined in reference to a state of the curve of 25
`road data with a certain surplus, and this is a steering angle
`range having a possibility that the driver may steer, such as
`a range from the left I 0° to the right 45° for a curve of right
`30R, for example.
`When the steering angle a exceeds this predetermined
`range, the vehicle comes to run outside of the normal road
`data. In this case, the operation jumps from the step 5 to the
`step 9 to enter the steering angle cooperating control mode
`similar to the case in which the vehicle does not run on the
`road data, and at the step 11 the light distribution is con- 35
`trolled under the same control mode.
`In the steering angle cooperating control mode when the
`vehicle runs outside of the road data, the optical axis angle
`8 is determined in response to the steering angle cooperating
`control map and FIG. 6 shows this control map by means of 40
`coordinates.
`The optical axis angle 8 is different in accordance with a
`vehicle speed and this angle is changed in a substantial
`proportion to the steering angle a under a high vehicle
`speed. In the case that the vehicle speed is low, there is 45
`provided a non-sensitive region where the optical axis angle
`8 is not much changed as long as the steering angle a is
`small and thus the lighting region is prohibited from being
`swung in a lateral direction upon sensitive reaction with a
`slight steering operation during the low speed running of the 50
`vehicle.
`After the steering angle the exceeds a predetermined
`range and the operation jumps from the step 5 to the step 9
`to enter the steering angle cooperating control mode, if the
`vehicle comes to run outside of the road data eventually, the
`operation jumps from the step 4 to the step 9 and the steering
`angle cooperating control mode is continued.
`Then, upon returning to the road data again, the operation
`advances to the step 4 and step 5 and if the steering angle a 60
`is within the predetermined range, the operation advances to
`the step 6.
`At the step 6, it is discriminated whether or not the
`crossing point node is present in front of the proper vehicle
`in a traveling direction and if the node is present, the
`operation jumps directly to the step 11 and the optical axis
`control is not performed temporarily, while maintaining the
`
`30
`
`55
`
`65
`
`6
`optical axis of the prior state just before, and if the crossing
`point node is not present, the operation advances to the step
`7.
`
`A reason why the optical axis control is not temporarily
`carried out when the crossing point nodes are present
`consists in the fact that there is a possibility that the vehicle
`runs out of the planned running path and advances on
`another road. For example, it may happen that, as shown in
`FIG. 10, although the planned running path (indicated by a
`broken arrow line) turns to the right, there is a parking area
`on the road turning to the left and the driver intends to drop
`in there. In this case, if the optical axis is swung rightward
`toward the planned running path, the amount of light on the
`left side where the vehicle actually runs is lack and at the
`same time the optical axis is unnecessarily swung. There(cid:173)
`fore, the optical axis control is temporarily prohibited to
`from being performed.
`When the crossing point nodes are not present in a
`forward area, the operation advances to the step 7 and it is
`discriminated whether or not a curve is present in the
`forward area, and if there is no curve at all, the operation
`jumps to the step 11 and the optical axis control is not carried
`out. If there is a curve in the forward area, the operation
`advances to the step 10 and enters the map information
`cooperating control mode which is the third control mode
`and then the optical axis control under the map information
`cooperating control mode is carried out at the step 11.
`At the map information cooperating control mode, it is
`analyzed whether the forward curve is directed, rightward or
`leftward, and how is the degree of curving of the curve in
`reference to the map information in the navigation system 30
`and a proper optical axis angle 8 is determined through
`retrieval of the map.
`For example, radii R of curves may be classified into
`some classes in a stepwise manner and a predetermined
`optical axis angle 8 may be set for each of the classes. The
`optical axis angle 8 is larger as the curve is sharper (as R is
`smaller).
`Since the map information cooperating control mode
`improves the visibility by varying the optical axis toward the
`planned running direction at an early stage before the
`steering wheel is actually turned, it is important that a timing
`of optical axis control is appropriate.
`In view of the foregoing, at the map information coop(cid:173)
`erating control mode, the timing control shown in FIG. 7 is
`carried out.
`A distance S (m) from the curve entrance at which
`controlling of the optical axis angle is to be started and a
`predetermined optical axis angle 8 (deg) to be set are
`determined in accordance with accuracy of the navigation
`system and a state of the curve.
`The accuracy of the navigation system is judged in
`reference to the degree of matching when the map matching
`is performed.
`The distance S ranging from the curve entrance to a point
`at which controlling of the optical axis is started is longer
`and a light distribution is changed at a more early stage as
`a planned optical axis angle 8 is larger. In addition, the light
`distribution is changed more early when the curve is sharp.
`In the case that the accuracy of the navigation system is
`good, it is controlled such that the light distribution is
`changed at an early stage and in the case that the accuracy
`is bad, the light distribution is changed later.
`This is due to the fact that if the light distribution is
`changed early even if the accuracy of the navigation system
`
`

`

`5,588,733
`
`7
`is bad, a returning of the optical axis angle subsequently
`becomes necessary, thus causing the control to be unstable
`and the· visibility is reduced rather than improved or an
`annoyance is given to the occupant in the vehicle.
`Details of the present light distributing control are as 5
`described above and in the case that no output of the
`direction indicating signal is present, the vehicle runs on the
`road data, the steering angle a is within a predetermined
`range and crossing point nodes and curves are not present in
`a forward traveling direction of the vehicle, the optical axis 10
`control is not carried out (steps 1, 2, 3, 4, 5, 6, 7 and 11).
`When the curve appears during this state, the operation
`enters the map information cooperating control mode and a
`light distributing control fit for the state of the curve state is
`carried out at a suitable timing in consideration of the
`accuracy of the navigation system (steps 1, 2, 3, 4, 5, 6, 7, 15
`10 and 11). When the steering angle a exceeds the prede(cid:173)
`termined range and the vehicle comes to run outside of the
`road data, the operation enters the steering angle cooperating
`control mode, and the light distributing control is carried out
`in response to the steering angle a under a consideration of 20
`the vehicle speed in reference to the steering angle cooper(cid:173)
`ating control map (steps 1, 2, 3, 4, 5, 9 and 11). When the
`output of the direction indicating signal is present, the
`operation most preferentially enters the direction indicating
`cooperating control mode so as to perform the light distrib- 25
`uting control on the basis of the direction indicating coop(cid:173)
`erating control map (steps 1, 2, 3, 8 and 11).
`In the case that the vehicle runs on the planned running
`path, no optical axis control is carried out ifthe forward road
`in a traveling direction of the vehicle is a linear one as shown
`in FIG. 8. However, as shown in FIG. 9, when there is a
`leftward curve in the forward location, a curve pre-noticing
`signal is present through an inputting of the map information
`(step 2), and the operation enters the map information
`cooperating control mode (step 10). In this case, the optical
`axis angle 9 is determined in view of the state of the curve
`and the like at first, and the optical axis control based on the
`optical axis angle 9 and the navigation accuracy or the like
`is started when the vehicle reaches the predetermined dis- 40
`tance S before the curve entrance and the light distribution
`is deflected leftward at a proper timing before the curve,
`resulting in that a superior visibility can be attained.
`In the case that there is a crossing point in a forward
`traveling direction of the vehicle as shown in FIG. 10, a
`forward crossing point pre-noticing signal is given by the
`inputted map information (step 2) and no optical axis control
`is carried out until the vehicle passes through the crossing
`point node (the operation jumps from step 6 to step 11).
`During this period, when the winker lever is operated, the
`operation enters the direction indicating cooperating control
`mode to perform the optical axis control under this control
`mode (the operation jumps from step 3 to step 8). Upon the
`operation of the winker lever, at first, the light distribution
`is changed in one action to the predetermined optical axis 55
`angle e steering direction so that the turning direction can be
`visually confirmed early, and then the lighting region is
`changed in correspondence with the steering angle when the
`steering angle exceeds the predetermined range, resulting in
`that the changing timing of the lighting region can be 60
`suitable and the visibility can be improved.
`When a steering angle a exceeds the predetermined
`range, the operation enters the steering angle cooperating
`control mode and the optical axis control is carried out under
`this control mode (the operation jumps from step 5 to step 65
`9) and also when the vehicle runs outside of the road data,
`the optical axis control is performed under the steering angle
`
`8
`cooperating control mode (the operation jumps from step 4
`to step 9), so that the control can be continued.
`Under both direction indicating cooperating control mode
`and steering angle cooperating control mode, a vehicle
`speed is taken into consideration for determining the optical
`axis angle 9, so that the light distribution which is most
`suitable for a vehicle speed can be attained and the visibility
`is improved.
`Although the right and left head lights in the aforesaid
`preferred embodiment are concurrently swung in the same
`direction to deflect the light distribution, it may also be
`available that only the head light at the turning side is swung
`or a certain difference is set between the swinging angles of
`the right and left head lights.
`There is also another method in which two bulbs are
`installed in one head light and the light distribution is
`changed by separately using one bulb illumination and
`two-bulb illumination, respectively.
`In addition, it may also be applicable that a sub-reflector
`is arranged against a main reflector and the sub-reflector is
`moved to change the light distribution.
`In addition, although the curve information of a road is
`stored in advance in the aforesaid preferred embodiment, it
`may also be ap