`
`<1a)A
`
`(43) Date ofA Publication 06.08.1997
`
`(21) Application No 97o1s22.o
`
`(22l Date of Filing 29.01.1991
`
`(51)
`
`INT CL5
`asoo 1/115
`
`(52) UK CL (Edition 0 l
`rm RMC R364 R41Y R765 max R789
`u1s 51934
`
`(56) Documents Cited
`EP 0699559 A1
`cs 2115929 A
`Us 5195315 A Us 4204270 A
`
`EP 0554663 A2
`
`(53)
`
`Field of Search
`UK CL (Edition 0) F4-R HMC
`WT CL6 3500 1/08 1/10 1/105 1/11 1/115
`Online : WPI, CLAIMS, JAPIO
`
`(30) Priority Data
`(31) oaoanoc
`
`(32) o1.o2.199s
`
`(33)
`
`JP
`
`_
`Apphcantisl
`Koito Manufacturing C0,, Ltd.
`
`llncorporated in Japanl
`
`_
`8-3, Takanawa 4-chomo, Mnnato-ku, Tokyo, Japan
`lnvento r(s)
`Knzuki Takahaslii
`
`Agent and/or Address for Service
`Gill Jennings 81 Every
`Broadgate House. 7 Eldon Street, LONDON,
`ECZM 7LH, United Kingdom
`
`(54) Controlling direction of vehicle lights
`
`(57) The illumination direction of lights in a vehicle is controlled by detecting vehicle posture leg height
`and/or inclination) and whether the vehicle is stationary and/or has passed through a change of road gradient,
`and directing the illumination of the lights to a desired direction in accordance with signals received from the
`posture detection device. Control means effect the direction change only when the vehicle is stationary and/or
`has passed through a change of gradient. Reference values related to time may be used to prevent unwanted
`light movements due to rough road surfaces and sudden stops or starts.
`
`3E¥'E‘i%1i§.?SE‘il§e mm
`
`VEHICLE RUNNING CONDlTl0N
`DETECTION DEVICE
`
`Vl7LL608Z89
`
`At least one drawing originally filed was informal and the print reproduced here is taken from a later filed formal copy.
`SL Corp. Exhibit 1019
`
`
`
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`ZOEQZOQoz_zz=mm_._o_:m>
`
`
`
`wosmozozowma
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`
`
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`
`
`
`DOES VEHICLE STOP
`
`VEHICLE POSTURE IS
`DETECTED
`
`VARIATION IN ROAD
`GRADIENT LARGE?
`
`HAS GIVEN TIME
`PASSED?
`
`LAMP ILLUMINATION
`DIRECTION IS
`CORRECTED
`
`LAMP ILLUMINATION
`DIRECTION IS NOT
`CORRECTED
`
`
`
`
`
`6/7
`
`FIG. 9
`
`13
`
`14
`
`CONSTANT
`
`VOLTAGE
`
`RESET
`
`SUPPLY l CIRCUIT I
`
`10
`
`COMPUTER
`
`8
`
`/U
`
`11
`
`V§,IIécE;'[',E
`
`SENSOR
`
`19
`
`19'
`
`°
`
`17
`
`-
`
`n-
`
`I. ____ __
`
`I IIIIIIIII IIII
`
`IIIIIIIII
`
`SENSOR
`
`NON-VOLATILE
`MEMORY 1"
`
`OSCILLATOR
`
`16
`
`
`
`7/7
`
`FIG. 10
`
`CONSTANT
`VOLTAGE
`SUPPL
`(NR
`
`RESET
`CIRCUIT
`
`-
`
`MICFI
`
`compu
`
`11
`
`"§.I*E'E%,E
`
`SENSOR
`
`NON-VOLATILE
`MEMORY
`
`1"’
`
`OSCILLATOR
`
`16
`
`I CIRCUIT
`
`
`
`2309774
`
`A VEHICLE LAMP ILLUMINATION DIRECTION CONTROL DEVICE
`
`The present invention relates to a vehicle lamp
`illumination direction control device which detects the
`
`posture of a vehicle and correctly adjust the illumination
`
`direction of a vehicle lamp so that it can be always kept in
`a predetermined direction.
`
`there has been known a device (a so
`Conventionally,
`called automatic leveling device) which, even when the
`inclination of a vehicle body varies,
`is capable of
`automatically adjusting the illumination direction of the
`
`vehicle lamp so that the illumination direction of the
`
`vehicle lamp can be kept at a predetermined direction.
`The
`device of this type, with the conditions of occupants (such
`as the number of occupants,
`the position arrangement of the
`occupants, and the like) as well as the loaded conditions of
`loads on board the vehicle taken into consideration, corrects
`manually the illumination angle of the vehicle lamp with
`respect to the initially adjusted value of the vehicle lamp
`so that the illumination state of the vehicle lamp can be
`always kept in a desired state,
`thereby to control the
`illumination direction of the vehicle lamp to provide desired
`light distribution.
`
`For example, when a load is applied to the rear
`portion of the vehicle,
`the device finds the then inclination
`angle of the vehicle body in the longitudinal direction
`thereof, and inclines the vehicle lamp downward because the
`illumination direction of which would be displaced upwardly
`of the reference direction if the posture of the vehicle lamp
`is left as it is,
`thereby adjusting the illumination
`direction of the vehicle lamp so that the vehicle lamp
`
`
`
`illumination direction can be always kept in the reference
`direction.
`
`in the above—mentioned manual adjustment,
`However,
`there is no guarantee that the illumination direction of the
`lamp can be always held in the optimum condition with respect
`to the posture of the vehicle. Therefore,
`there is
`conventionally known a device which includes a device for
`detecting the posture of the vehicle by detecting the
`inclination and height of a vehicle body, and calculates the
`amount of variations in the inclination of the vehicle based
`
`direction of the lamp.
`
`in the above-mentioned automatic adjustment
`However,
`device, since the lamp is driven with high frequency, an
`actuator used in a drive mechanism for driving the lamp is
`required to show high response property and high durability.
`Due to this,
`the adjustment device is expensive and consumes
`a large amount of electric power.
`
`‘Therefore,
`inconveniences,
`
`in order to avoid the above
`
`in such device, when the vehicle
`is standing still. However,
`stops once on a road having a gradient,
`the illumination of
`the lamp cannot be corrected until the vehicle stops again on
`a road having a small gradient, which raises another
`inconvenience.
`For example, when the vehicle stops on a
`downhill road, because the vehicle posture detect device
`detects that the front portion of the vehicle is lower in
`position,
`the illumination direction of the lamp is corrected
`to a position which is set a little upwardly of a reference
`position. After then, when the driver starts the vehicle
`while the illumination direction of the lamp remains as it is
`corrected upwardly, and the vehicle passes through the
`
`
`
`downhill slope and then runs into a flat road,
`
`that is, even
`
`when the vehicle runs along the flat road,
`
`the illumination
`
`direction of the lamp is still left in the upwardly corrected
`
`condition until the vehicle stops again, which can cause an
`
`increase in the glare onto an oncoming vehicle or can worsen
`
`the visibility of the driver of the present vehicle.
`
`Accordingly, it is an object of the invention to
`
`provide a vehicle lamp illumination direction control device
`
`capable of not only reducing the cost thereof but also
`
`correctly adjusting the illumination direction of a lamp
`
`according to the stationary condition of the vehicle and the
`
`amount of variations in the gradient of the road to thereby
`
`improve the visibility thereof and guarantee the safety of
`
`the running of the vehicle.
`
`In attaining the above object, according to the
`
`invention,
`
`there is provided a vehicle lamp illumination
`
`direction control device so structured as to change the
`
`illumination direction of a vehicle lamp according to the
`
`vertical inclination of a vehicle in the advancing direction
`
`thereof,
`
`the vehicle lamp illumination direction control
`
`device comprising:
`
`a vehicle posture detection device for detecting the
`
`posture of the vehicle;
`
`a vehicle running condition detection device for
`
`detecting the running conditions of the vehicle including the
`
`stationary condition thereof;
`
`a drive device for directing the illumination light
`
`of the lamp to a desired direction; and,
`
`control device, when it is judged in accordance with
`
`a signal from the vehicle running condition detection device
`
`that the vehicle is in the stationary condition thereof and
`
`when it is judged that the vehicle has run from a road having
`
`
`
`a small gradient into a road having a large gradient or the
`vehicle has run from a road having a large gradient into a
`road having a small gradient, for transmitting to the drive
`device a signal for correcting the illumination direction of
`the lamp in a predetermined direction in accordance with a
`
`signal from the vehicle posture detection device.
`
`Therefore, according to the invention, only when the
`vehicle is found stationary and when it is found that the
`vehicle has run from a road having a small gradient into a
`road having a large gradient or the vehicle has run from a
`road having a large gradient into a road having a small
`gradient,
`the illumination direction of the lamp can be
`corrected.
`
`In the accompanying drawings:
`
`Fig.
`1 is a block diagram of the structure of a
`vehicle lamp illumination direction control device according
`to the invention;
`
`2 is a schematic view of a vehicle, explaining
`Fig.
`height detection device provided in the vehicle;
`Fig. 3,
`together with Figs.
`4 to 6, is a schematic
`graphical representation of the amount of variations with
`time in the output signal of the height sensor when the
`in
`vehicle runs along a road having a large gradient; and,
`particular, Fig.
`3 shows the variations in the output of the
`height sensor when the vehicle firstly runs along an uphill
`slope and then runs along a road having a small gradient;
`Fig.
`4 shows the amount of variations in the output
`of the height sensor when the vehicle firstly runs along a
`road having a small gradient and then runs along an uphill
`slope;
`
`5 shows the amount of variations in the output
`Fig.
`of the height sensor when the vehicle firstly runs along a
`
`
`
`downhill slope and then runs along a road having a small
`
`gradient;
`
`Fig.
`
`6 shows the amount of variations in the output
`
`of the height sensor when the vehicle firstly runs along a
`
`road having a small gradient and then runs along a downhill
`
`slope;
`
`Fig.
`
`7 is a flow chart of a processing for correction
`
`of the illumination direction of the lamp;
`
`Fig.
`
`8 is a graphical representation in which
`
`variations in the output signal levels of the height sensor,
`
`the illumination angles of the lamp, and the vehicle speeds
`
`are shown in combination;
`
`Fig.
`
`9 is a circuit block diagram of a first
`
`embodiment of a vehicle lamp illumination direction control
`
`device according to the invention; and,
`
`Fig. 10 is a circuit block diagram of a second
`
`embodiment of a vehicle lamp illumination direction control
`
`device according to the invention.
`
`Now, description will be given below of the
`
`embodiments of a vehicle lamp illumination direction control
`
`device according to the invention with reference to the
`
`accompanying drawings.
`
`At first, Fig.
`
`1 shows the basic structure of the
`
`present invention,
`
`in which an illumination direction control
`
`device 1 is composed of vehicle posture detection device 2,
`vehicle running condition detection device 3, control device
`
`4, drive device 5
`
`(which is composed of drive control device
`
`5a and a drive mechanism Sb), and a lamp 6.
`
`The vehicle posture detection device 2 is used to
`
`detect the posture of a vehicle (including the vertical
`inclination of the vehicle in the advancing direction
`thereof).
`For example, when there is used height detection
`
`
`
`device 7 which detects the height of the body of the vehicle,
`as shown in Fig. 2,
`there are available a method which
`
`measures a distance L between the height detection device 7
`
`and a road surface G by use of detect waves such as
`
`ultrasonic waves,
`
`laser beams or the like, and a method in
`
`which the height detection device 7 detects the expansion and
`contraction amount x of a suspension 8 in order to detect the
`
`amount of variations in the vertical position of the axle of
`the vehicle.
`The two methods are both advantageous in that
`the existing facilities of the vehicle can be used for
`
`detection of the posture of the vehicle.
`
`The output of the vehicle posture detection device 2
`is sent to the control device 4 and is used as basic
`
`information for correction calculation of the illumination
`direction of the lamp 6.
`
`The vehicle running condition detection device 3 is
`
`used to detect the running conditions of the vehicle
`(including the stopping or stationary condition thereof),
`while the detect signal of the vehicle running condition
`detection device 3 is transmitted to the control device 4.
`As the vehicle running condition detection device 3, for
`example,
`there can be used vehicle speed detection device
`which is one of the existing facilities of the vehicle.
`Also, every kind of information can be used, provided that it
`can be used to detect the running conditions of the vehicle.
`When the control device 4 receives the detect signal
`of the vehicle running condition detection device 3 and finds
`from this detect signal that the vehicle is standing still,
`the control device 4,
`in accordance with information on the
`vehicle posture obtained from the vehicle posture detection
`device 2,
`transmits to the drive signal 5 a control signal
`for correction of the illumination direction of the lamp 6.
`For example,
`in the stationary condition of the vehicle, when
`the front portion of the vehicle is situated lower (or
`
`
`
`higher) than the rear portion thereof,
`
`the illumination
`
`direction of the lamp 6 is adjusted in the upward (or
`
`downward) direction so that the illumination direction can be
`
`always held substantially in the horizontal direction.
`
`By the way,
`
`the vehicle does not always stop on a
`
`road having no gradient but, as described above,
`
`the vehicle
`
`is sometimes caused to stop on the slanting road.
`
`In this
`
`case, with use of the above-mentioned method for adjusting
`the illumination direction of the-lamp only when the vehicle
`is caused to stop,
`the thus adjusted illumination direction
`
`of the lamp cannot be corrected until the vehicle stops next.
`In view of this,
`the control device 4 is structured
`
`such that, based on the information from the vehicle posture
`detection device 2, it can detect the amount of variations in
`
`the gradient of the road and, therefore, when the road
`
`gradient varies suddenly, it can correct the illumination
`
`direction of the lamp 6.
`
`3 to 6 are respectively explanatory views
`Now, Figs.
`of a method for detecting the amount of variations in the
`
`road gradient when a height sensor is used as the vehicle
`
`in these figures, an axis of
`posture detection device 2 and,
`abscissa expresses the time t and an axis of ordinate
`
`that is,
`expresses the output level V of the height sensor;
`in these figures,
`there is shown an example of the amount of
`variations in the output level V with the passage of time (
`by the way, for the purpose of simplified expression,
`the
`term "with the passage of time" is sometimes expressed as
`"with time" in this specification).
`
`3 shows schematically the amount
`In particular, Fig.
`of variations in the output level V when the vehicle runs
`first along an uphill slope and thereafter runs along a road
`having a small gradient.
`In this case, when the vehicle runs
`
`over the uphill slope,
`
`the output level V falls down
`
`suddenly.
`
`
`
`Also, Fig.
`
`4 shows schematically the amount of
`
`variations in the output level V when the vehicle runs first
`
`along a road having a small gradient and thereafter runs
`
`along an uphill slope.
`
`In this case, when the vehicle starts
`
`to run the uphill slope,
`suddenly.
`
`the output level V rises up
`
`Fig.
`
`5 shows schematically the amount of variations
`
`in the output level V when the vehicle runs first along a
`downhill slope and thereafter runs along a road having a
`small gradient.
`In this case, when the vehicle has run
`
`through the downhill road,
`suddenly.
`
`the output level V rises up
`
`Fig.
`6 shows schematically the amount of variations
`in the output level V when the vehicle runs first along a
`road having a small gradient and thereafter runs along a
`downhill slope.
`In this case, when the vehicle starts to run
`along the downhill slope,
`the output level V falls down
`suddenly.
`
`These figures show clearly that the magnitude of the
`amount of variations in the road gradients is reflected on
`the amount of variations in the outputs of the height sensor
`when the vehicle runs from the road having a small gradient
`to the road having a large gradient or when the vehicle runs
`from the road having a large gradient to the road having a
`small gradient.
`
`Therefore, when the amount of variations with time of
`the detect signal of the vehicle posture detect signal 2 is
`equal to or larger than a reference value, it may be judged
`that the gradient of the road has varied, and the
`illumination direction of the lamp 6 may be corrected in
`accordance with the detect signal of the vehicle posture
`detection device 2. That is, according to this way of
`correction, when the vehicle moves from the uphill or
`downhill slope to the road having a small gradient, or vice
`
`
`
`the illumination direction of the lamp 6 can be
`versa,
`adjusted in a proper direction.
`
`the control device
`in the present method,
`By the way,
`4 is structured such that it can judge the amount of
`variations in the road gradients according to the detect
`information provided by the vehicle posture detection device
`2, which can in turn simplify the structure of the
`illumination direction control device. However,
`the
`
`, for example, a device
`for detecting the road gradients or the amounts of variations
`therein may be provided separately from the vehicle posture
`detection device 2 and the control device 4 may judge the
`
`detection device.
`
`in order to prevent the illumination direction
`Also,
`of the lamp 6 from being corrected inadvertently when a
`sudden change in the posture of the vehicle occurs
`temporarily or due to the wrong operation of the lamp 5
`caused by external disturbances, for example,
`when the
`vehicle makes a sudden start or a sudden stop,
`preferably, a
`threshold value with respect to time may be set in detection
`of the road gradient and, only when the amount of variations
`
`than the threshold value,
`the illumination direction of the
`lamp 6 may be corrected. Also,
`these threshold values may be
`
`
`
`set in various manners, for example,
`
`they may be set as a
`
`constant value, or may be set as a variable which varies
`
`according to the speeds of the vehicle.
`
`7 is a flow chart of a processing to be
`Now, Fig.
`performed by the control device 4. At first, in Step S1, it
`is checked in accordance with the information from the
`
`vehicle running condition detection device 3 whether the
`
`vehicle is stopped or not.
`
`If it is found that the vehicle
`
`then the processing advances to Step S5 and, if
`is stopped,
`the vehicle is found running,
`then the processing advances to
`Step S2.
`
`After the posture of the vehicle is detected by the
`vehicle posture detection device 2 in Step S2,
`in Step S3, it
`is checked from the amount of variations with time in the
`detect signal whether the amount of variations in the
`
`gradient of the road is large or not.
`If it is found that
`the amount of variations in the road gradients is large,
`then
`the processing advances to Step S4 and, if not,
`then the
`processing advances to Step S6.
`
`In Step 54, it is checked whether a state in which
`the amount of variations of the detect signal supplied by the
`vehicle posture detection device 2 is equal to or more than a
`given reference value continues for a given period of time or
`longer or not.
`If it is found that such state continues,
`then the processing advances to Step S5 and, if not,
`then the
`processing goes to Step S6. Here, when a threshold value
`relating to the running distance of the vehicle is set
`instead of setting a threshold value relating to the above-
`mentioned continuing time,
`in Step S4, it may be checked
`whether a state in which the amount of variations in the
`detect signal supplied by the vehicle posture detection
`device 2 is equal to or more than a given reference value
`continues over a given running distance or not.
`
`
`
`In Step S5,
`
`in accordance with the information from
`
`the vehicle posture detection device 2,
`
`the control device 4
`
`transmits to the drive control device 5a a control signal
`which causes the illumination direction of the lamp 6 to be
`kept in a predetermined direction, and the illumination
`
`direction of the lamp 6 is corrected through the drive
`mechanism 5. After then,
`the processing goes back to the
`first step S1.
`
`Also,
`in Step 6,
`the correction of the illumination
`direction of the lamp 6 is not carried out but the processing
`returns to the first step S1.
`
`The correction of the illumination direction of the
`lamp 6 in Step S5 is carried out by the drive device 5 based
`on the control signal transmitted from the control device 4
`and, as a method for executing such correction,
`there are
`available two methods as follows:
`
`1)
`2)
`
`a method for inclining the entire lamp, and,
`a method for moving the component (such as a
`lens, a reflector, a shade or the like) of
`the optical system of the lamp.
`In particular,
`the method 1) is the simplest method
`that can change the illumination pattern of the lamp 6 within
`a vertical plane,
`in which the entire lamp is rotated about
`the rotary shaft thereof to thereby change the illumination
`angle of the lamp 6 with respect to a horizontal plane
`in the
`including the optical axis of the lamp.
`For example,
`method 1),
`there can be used a drive mechanism in which the
`right and left side surfaces of the lamp 6 are supported
`rotatably, and the rotary shaft of the lamp 6 is rotated
`directly by a drive source such as a motor or the like, or a
`member fixed to or formed integrally with the lamp 6 is
`rotated by the drive device 5.
`‘As an example of such lamp,
`there is available a lamp including a mechanism which can use
`the rotational force of the motor as the rotational force of
`
`
`
`the lamp through a transmission mechanism using a worm and a
`worm wheel (for example, see Japanese Patent Publication No.
`Sho. 63-166672).
`
`there is employed a structure
`in the method 2),
`Also,
`in which the reflector of the lamp 6 is rotated by the drive
`device 5 within a vertical plane including the optical axis
`of the lamp to thereby change the direction of the reflected
`light of the reflector.
`For example,
`there is available a
`structure in which part of the reflector is rotatably
`supported on the lamp and,
`in order that a screw member
`mounted on the other part than the lamp for adjusting the
`inclining angle of the remaining portions of the reflector
`can be rotated by a motor,
`there is employed a transmission
`mechanism including a worm and a worm wheel (for example, see
`Japanese Patent Publication No. Sho. S9~l9544l); or,
`there is
`also available a structure in which the lens is inclined by
`the drive device 5 to thereby change the direction of the
`illumination light of the lamp that has passed through the
`present lens (for example, see Japanese Patent Publication
`No. Hei. 7-37405). Here,
`instead of inclining the whole of
`the reflector and lens, part of them may be controlled in
`position to thereby change the main portions of the
`illumination light in a desired direction.
`
`Also, when a shade is interposed between the
`reflector and lens,
`the shade may be moved by the drive
`device 5 to thereby change a light and shade boundary in the
`light distribution pattern of the lamp 6
`in the vertical
`direction (for example, see Japanese Patent Publication No.
`Hei. 7-29401).
`
`there are also possible other various
`Further,
`embodiments according to the combinations of the optical
`components of the lamp 6; for example,
`the reflector and
`light source,
`the lens and reflector, or the lens and shade
`may be moved together by the drive device 5 to thereby change
`
`
`
`the direction of the illumination light of the lamp in the
`vertical direction.
`
`In addition,
`
`in either of the method 1) or 2), of
`
`course,
`
`the illumination direction of the lamp 6 can be
`
`controlled in stages or continuously.
`
`Now, Fig.
`
`8 is a graphical representation in which,
`
`when the vehicle runs down along a downhill slope from a road
`
`having a small gradient and runs again for a short time along
`
`a road having a small gradient and, after then, it stops,
`
`there are shown the respective amounts of variations with
`
`time in the output level V of the height sensor,
`
`in the
`
`illumination angle 6 of the lamp 6, and in the output signal
`
`vs of the vehicle speed sensor. Here,
`
`in the graph shown in
`
`the upper stage of Fig.
`
`8 and showing the amount of
`
`variations in the output level V, reference character rVaJ
`
`represents a detect level detected on the downhill slope and
`Vb represents a detect level detected on the road having a
`small gradient, while Tsh stands for a judgment
`time relating
`to the detection of the variations in the road gradients.
`Also,
`in the graph shown in the middle stage of Fig.
`8 and
`showing the amount of variations in the illumination angle 6,
`Ba expresses an illumination angle when the vehicle is
`
`running on the slanting slope, while 9b expresses an
`illumination angle when the vehicle is standing still.
`8 and
`Further,
`in the graph shown in the lower stage of Fig.
`showing the variations in the output signal vs, a period Tm,
`during which pulse trains continue, stands for a period
`during which the vehicle is running, whereas a period To,
`during which no pulse train exists, represents a period
`during which the vehicle is standing still.
`
`In this example, when the vehicle runs from a road
`
`the amount of
`having a small gradient into a downhill slope,
`variations in the output level V of the height sensor is
`equal to or more than a reference value and such high
`
`
`
`variation amount state continues for a time equal to a
`judging time Ts or longer. Therefore,
`the illumination angle
`of the lamp 6 is corrected from zero to ea after the passage
`of a time Tsh. And, when the vehicle runs into a road having
`a small gradient after the vehicle has run through the
`downhill slope,
`the variation amount of the output level V of
`the height sensor is equal to or more than a reference value
`and such high variation amount state continues for a time
`
`the
`equal to a judging time Ts or longer. Therefore,
`illumination angle of the lamp 6 is corrected from 8a to zero
`after the passage of the time Tsh. After then,
`if the
`vehicle is caused to stop in a period To,
`then the
`illumination angle of the lamp 6 is corrected according to
`the then posture of the vehicle.
`For example, when the
`loading condition of the vehicle is varied by unloading the
`cargo,
`the illumination angle of the lamp 6 is corrected to
`an angle of 9b.
`
`As described above, a threshold value (which is
`expressed as Ls) of the running distance can be substituted
`for the judging time Tsh,
`the illumination angle 6 can be
`corrected when the vehicle runs continuously for a distance
`equal to or larger than the threshold value Ls with the
`detect level of the height sensor remaining higher than the
`reference value, or the threshold value can be caused to vary
`with respect to a vehicle speed vs in accordance with an
`equation Ts
`Ls/vs (#0).
`
`in the above description, for the convenience
`Also,
`of explanation,
`the number of height sensors to be provided
`on the vehicle is set as one. However,
`this is not
`limitative but other various embodiments are also possible,
`for example,
`some of a plurality of sensors provided in the
`front and rear portions and/or right and left portions of the
`vehicle can be selected and the detect signals of the
`selected sensors can be used.
`In particular, out of sensors
`
`
`
`respectively provided in the front and rear portions of the
`
`vehicle as well as in the right and left portions thereof,
`
`the sensors provided in the right and left direction can be
`
`selected and the average value of the selected sensors can be
`
`used; or, out of four sensors which are respectively provided
`
`in the front, rear, right and left portions of the vehicle,
`
`there can be selected a pair of sensors positioned diagonally
`
`with respect to each other in a quadrangle having four
`
`vertices respectively consisting of the positions of the four
`
`sensors (for example, a pair of a left and front sensor and a
`
`right and rear sensor, or a pair of a right and front sensor
`
`and a left and rear sensor), and only the detect signals of
`
`the thus selected pair of sensors can be used; or,
`
`there can
`
`be used only the detect signals of two sensors which are
`
`respectively positioned in the front and rear portions of the
`
`vehicle and are also positioned on the same straight line
`
`extending in the longitudinal direction of the vehicle (for
`
`example, sensors which are positioned in the front and rear
`
`portions of the vehicle on the right or left side of the
`
`vehicle).
`
`Now,
`
`in Figs.
`
`9 and 10,
`
`there are shown the first and
`
`second embodiments of a vehicle lamp illumination direction
`
`control device according to the invention.
`
`In particular, Fig.
`9 shows a block diagram of a
`vehicle lamp illumination direction control device according
`to the first embodiment of the invention.
`In the present
`embodiment,
`the vehicle posture detect member 2 is composed
`of four height sensors 9 which are respectively provided in
`the neighborhood of the front and rear as well as right and
`left wheels of the vehicle.
`
`includes a microcomputer
`the control device 4
`Also,
`10 into which there are input the detect voltages of the four
`height sensors 9, and the output signals of a vehicle speed
`sensor 11 corresponding to the previously described vehicle
`
`
`
`running condition detection device 3. When a turn-on switch
`12 for the lamp 6 is put into operation, a supply voltage
`from a constant voltage supply circuit 13 and a reset signal
`from a reset circuit 14 are supplied to the microcomputer 10.
`Also, a non-volatile memory 15 (such as an electrically
`erasable EEPROM, or the like) for storing control programs
`and data values therein) and an oscillator 16 used to
`generate a clock signal are additionally attached to the
`microcomputer 10.
`
`there is input by
`into the microcomputer 10,
`And,
`switch device 17 a select signal which is used to instruct
`whether the above-mentioned control on the illumination
`direction of the lamp is to be carried out or not.
`The
`reason for such input of the select signal is as follows:
`that is, when a lamp is mounted on a vehicle and the
`illumination direction of the lamp is initially adjusted, or
`when the lamp is inspected, if the above-mentioned correction
`control on the illumination direction of the lamp is carried
`out,
`then the adjusting operation and inspection are
`difficult to perform.
`In this case, by operating the switch
`device 17,
`the illumination direction of the lamp may be set
`in a non—control state in which no correction control is
`carried out (for example,
`in a state in which the
`illumination angle of the lamp is fixed at a given angle).
`Here, if the detect data of the height sensors 9
`in the
`initial adjustment time are stored in the above-mentioned
`memory 15,
`
`after the initial adjustment time can be controlled with the
`vehicle posture in the initial adjustment time as a
`reference.
`
`is used to
`convert the output signal of the microcomputer 10 into an
`analog signal and transmits it to actuators 19 and 19’
`
`
`
`are disposed downstream thereof.
`
`In this case,
`
`there is
`
`employed an actuator of a current input type and the lamp or
`the components thereof are driven by these actuators 19 and
`
`19'
`
`to thereby correct the illumination direction of the
`
`lamp. Here, one actuator 19 is used to control the
`
`illumination direction of the lamp provided on the right side
`
`of the front portion of the vehicle, while the other actuator
`
`19’ is used to the illumination direction of the lamp
`
`provided on the left side of the front portion of the
`vehicle.
`
`Now, Fig. 10 shows a vehicle lamp illumination
`
`direction control device 8A according to the second
`
`embodiment of the invention,
`
`in which there are used a
`
`potentiometer and a direct current motor as the actuators
`
`thereof.
`
`Since most of the second embodiment is similar to
`
`the similar portions thereof are given
`the first embodiment,
`the same designations as the corresponding portions of the
`first embodiment and thus the description thereof is omitted
`here.
`
`In the present embodiment,
`
`there are provided two
`
`motor drive circuits 20 and 20' which correspond to the
`above-mentioned drive control device 5a and are respectively
`used to control the rotational movements of two motors 21 and
`
`in accordance with a control signal output from the
`21'
`microcomputer 10.
`
`the drive mechanism 5 is composed of
`In this case,
`the motors 21 (2l') and potentiometers 22 (22').
`For
`example, when a reflector disposed within the lamp is
`inclined in a vertical plane including the optical axis
`thereof to thereby change the illumination direction of the
`
`lamp,
`the reflector is inclined by the motors 21 and 21' and
`then the inclining angle of the reflector is detected by the
`potentiometers 22 and 22’
`(including A/D conversion and the
`like) and is input to the microcomputer 10. That is,
`the
`
`
`
`microcomputer 10 continues to transmit the control signal to
`the motor drive circuits 20 and 20' until the inclining angle
`of the reflector detected by the potentiometers 22 and 22'
`becomes a target angle.
`
`the lamp or
`Besides this, according to the invention,
`the components thereof can be driven or controlled by use of
`a stepping motor to thereby correct the illumination
`
`direction of the lamp.
`
`In other words,
`
`the concret