United States Patent 1191
`Shibata et a1.
`
`US005404278A
`[11] Patent Number:
`[45] Date of Patent:
`
`5,404,278
`Apr. 4, 1995
`
`[54] VEHICULAR CORNERING LAMP SYSTEM
`_
`_
`_
`_
`_
`_
`[75] Inventors: Hlrok} Slnbata; H1119!“ 01198111, both
`of shlzuoka, Japan
`[73] Assignee: Koito Manufacturing Co., Ltd.,
`Tokyo, Japan
`[21] Appl. No.: 153,041
`_
`[221 Flled‘
`Nov- 17’ 1993
`[30]
`Foreign Application Priority Data
`
`.
`
`318/603
`4,908,560 3/1990 Shibata et al.
`362/37
`4,943,893 7/1990 Shibata et al.
`315/81
`4,963,794 10/1990 Shibata et a1.
`4,970,906 11/1990 Shibata et al. ................... .. 73/865.8
`FOREIGN PATENT DOCUMENTS
`
`3704029 8/1988 Germany .
`
`Primary Examiner-Ira S. Lazarus
`Assistant Examiner-—L. Heyman
`Attorney, Agent, or Firm-Sughrue, Mion, Zinn,
`Macpeak & Seas
`
`Nov. 19, 1992 [JP]
`Japan ........................... .. 4-085465 U
`ABSTRACT
`[57]
`[51] Int. Cl.6 ............................................. .. B60Q 1/12
`[52] US. Cl. ................................... .. 362/83.3; 362/36; A vehicular cornering lamp system in which the
`362/37; 362/41; 315/81
`amount of electric power consumed by the lamp is
`[58] Field of Search ..................... .. 362/36, 41, 37, 40,
`minimized. Until the angle of rightward (leftward)
`362/ 83.3; 315/81
`steering with respect to the position of straight-ahead
`steering reaches a predetermined angle 9;; (0],), the
`right (left) SI lamp remains turned off and the illuminat
`ing angle thereof is ?xed to 30° in the right (left) direc
`tion. After the point of time when the steering angle
`reaches 9R R (01), the right (left) 51 lamp is turned on
`and the illuminating angle is changed in accordance
`with Steerin direction
`g
`'
`
`[56]
`
`References Cited
`
`U'S' PATENT DOCUMENTS
`l,174,l54 3/1916 Howard .............................. ._ 362/40
`3,023,344 2/19'62' Owings ........... ..
`362/37
`4'663’696 5/1987 Mlywwa et al-
`362/80
`4,733,333 3/1988 Slubata et al.
`362/40
`4,827,388 5/ 1989 Miyazawa
`362/284
`4,831,506 5/1989 Miyazawa
`.. 362/284
`4,860,601 8/1989 Shibata et al. ................... 1. 73/8658
`
`>
`10 Claims, 6 Drawing Sheets
`
`ILUMINATNG DIRECTIOV
`
`8101111
`
`OFF
`
`30°
`
`ON
`
`1
`
`l
`
`I-1
`
`l-Z
`
`9L
`
`0
`
`- 9R
`
`STEERING ANGLE
`
`RIGHT
`
`LEFT
`
`.
`
`lI-Z
`
`lI-1
`
`30‘l
`
`(N
`
`OFF l
`LEFT
`
`Page 1 of 12
`
`BMW 1016
`
`

`
`US. Patent
`
`Apr. 4, 1995
`
`Sheet 1 of 6
`
`5,404,278
`
`FIG. 7
`
`B-BL
`
`Page 2 of 12
`
`

`
`US. Patent
`
`Apr. 4, 1995
`
`Sheet 2 of 6
`
`5,404,278
`
`FIG. 2
`AVPLIF‘IIIATION
`'
`
`Ammuu/
`
`0
`
`$221‘?
`
`fLKkcj?REQUENCY
`
`f1 f2
`
`8%
`
`FIG. 3(a) Vu
`
`Avm .
`
`FIG. 3m) _4/\_\'
`
`F15 3(c)
`
`FIG. 3(d)
`
`Page 3 of 12
`
`

`
`US. Patent
`
`Apr. 4, 1995
`
`Sheet 3 of 6
`
`5,404,278
`
`FIG. Mam“ I?
`VIlL
`
`I
`
`FIG. 4/1313: '
`
`FIG. 4(a) -.\
`
`FIG. 4/0’)
`
`Page 4 of 12
`
`

`
`US. Patent
`
`Apr. 4, 1995
`
`Sheet 4 of 6
`
`5,404,278
`
`ILLLHINATING DIRECTION
`
`RIGHTT
`
`oFF>
`
`go,
`
`ON
`
`I"
`
`1-2
`
`6L
`
`0
`
`9R
`
`STEERING ANGLE
`
`LEFT
`
`-
`
`3o,
`
`'
`RIGHT
`
`_
`
`11-2
`
`11-1
`
`an
`
`EFF 1
`
`LEFT
`.
`
`Page 5 of 12
`
`

`
`US. Patent
`
`Apr. 4, 1995
`
`Sheet 5 of 6
`
`5,404,278
`
`FIG. 6
`ILLUMINATING ANGLE
`RIGHTT 90*
`
`m m .m
`
`2
`
`. ‘ H .m T
`.U 1
`
`Um m.
`
`.... -
`
`
`
`w . =1, @ow w
`
`
`
`w-:...m ...... i .
`
`.m m Iv r T
`9. .2 .... : m
`
`........ -H
`
`...... :nwim.
`{my
`‘mm
`
`- - .w w
`
`Page 6 of 12
`
`

`
`US. Patent
`
`-
`
`Apr.4,1995
`
`Sheet, 6 of 6
`
`5,404,278
`
`13L-23
`
`13L-2 13L-22
`
`Page 7 of 12
`
`

`
`1
`
`5,404,278
`
`VEHICULAR CORNERING LAMP SYSTEM
`
`2
`tion of the vehicle while the left lighting means is turned
`off until the angle of leftward steering with respect to
`the position of straight steering reaches a predetermined
`value 0; a ?rst illuminating direction changing means
`for changing the illuminating direction of the right
`lighting means while the right lighting means is turned
`on in accordance with the steering direction of the
`vehicle after the steering angle reaches the predeter
`mined value 01;; and a second illuminating direction ‘
`changing means for changing the illuminating direction
`of the left lighting means in accordance with the steer
`ing direction while the left lighting means is turned on
`after the angle of steering reaches the predetermined
`value 01,.
`According to the present invention, in the case where
`the steering angle is in a range from a predetermined
`value 0L to a predetermined value 0R, both the left
`lighting means and the right lighting means are turned
`off and held in a standby state, with the illuminating
`directions thereof set at predetermined angles in respec
`tive left and right directions with respect to the forward
`direction of the vehicle.
`When the steering angle reaches OR, the right lighting
`means is turned on, and the illuminating direction
`thereof is then changed in accordance with the steering
`direction of the vehicle.
`On the other hand, when the steering angle reaches
`01,, the left lighting means is turned on, and the illumi
`nating direction thereof is then changed in accordance
`with the steering direction of the vehicle.
`
`20
`
`BACKGROUND OF THE INVENTION
`The present invention relates to a vehicular cornering
`lamp system for variably changing the illuminating
`direction of a lighting device in accordance with a di
`rection of steering of the vehicle.
`Automotive vehicles have a pair of headlamps pro
`vided on left and right sides of the front of the vehicle
`in order to provide illumination in the forward direc
`tion. The headlamps are ?xedly mounted so as to pro
`vide illumination only the forward direction of the vehi
`cle. As a result, when the vehicle is traveling on a curry
`road, it is impossible to always provide suf?cient illumi
`nation in the direction of movement of the car, some
`times creating a dangerous situation.
`To solve this problem, the addition of auxiliary head
`lamps having a wide diffusion angle may be considered.
`However, with this approach there arises a problem in
`that the road surface may be made to look relatively
`dark when the vehicle is traveling on a straight road
`because of light re?ected from a guardrail along the
`shoulder of the road.
`There has been recently been proposed a cornering
`lamp system in which “steering interlock” (SI) lamps
`are provided whose illuminating direction (illuminating
`angle) is varied in accordance with the steering direc
`tion of the vehicle so that the road in the direction of
`movement of the vehicle is continuously illuminated by
`30
`the SI lamps.
`For example, there has been proposed a cornering
`lamp system in which the illuminating direction of a
`right SI lamp is changed when steering to the right
`while the illuminating direction of a left SI lamp is ?xed
`35
`in the forward direction (straight-ahead direction: illu
`minating angle 0°), whereas the illuminating direction
`of the left SI lamp is changed when steering to the left
`while the illuminating direction of the right SI lamp is
`?xed in the forward direction.
`If such a cornering lamp system is employed, light
`re?ected from the guardrail can be eliminated by reduc
`ing the diffusion angle, and safety for nighttime driving
`is enhanced because bright illumination is always pro
`vided in the direction of movement of the vehicle.
`In the above-mentioned cornering lamp system, how
`ever, auxiliary headlamps (left and right SI lamps) other
`than the headlamps must be operated continuously.
`There is a problem, therefore, in that the total amount
`of electric power consumed by the headlamps is high.
`50
`
`45
`
`25
`
`55
`
`SUMMARY OF THE INVENTION
`The present invention is intended to solve the afore
`mentioned problems, and hence has as an object the
`provision of a vehicular cornering lamp system in
`which the amount of electric power consumed by the
`headlamps can be reduced.
`To attain the foregoing and other objects, a cornering
`headlamp system of the present invention includes: a
`?rst illuminating direction ?xing means for ?xing the
`illuminating direction of right lighting means at a prede
`termined angle in the rightward direction of the vehicle
`while the right lighting means is turned off until the
`angle of rightward steering with respect to the direction
`or position of straight steering reaches a predetermined
`65
`value 01;; a second illuminating direction ?xing means
`for ?xing the illuminating direction of left lighting
`means at a predetermined angle in the leftward direc
`
`60
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is a circuit diagram of a vehicular cornering
`lamp system constructed according to a preferred em
`bodiment of the present invention;
`FIG. 2 is a graph showing frequency-ampli?cation
`factor characteristics of a differentiator in the cornering
`lamp system of FIG. 1;
`FIGS. 3(a)—3(d) are waveform diagrams for explain
`ing the basic operation of a right illuminating direction
`control circuit in the case where an operation mode
`switching circuit and a lamp on/off circuit are not pro
`vided in the cornering lamp system;
`FIGS. 4(a)-4(d) are waveform diagrams for explain
`ing the basic operation of a right illuminating direction
`control circuit in the case where an operation mode
`switching circuit and a lamp on/off circuit are provided
`in the cornering lamp system;
`FIG. 5 is a graph showing illuminating direction
`changing characteristics and turn-on/off characteristics
`of the right and left SI lamps in the inventive cornering
`lamp system;
`FIG. 6 is a graph showing another example of the
`illuminating direction changing characteristics and
`turn-on/off characteristics of the right and left SI
`lamps;
`FIG. 7 is a schematic structural diagram of a sub
`reflector moving type SI lamp used for both of the right
`and left SI lamps; and
`‘
`FIG. 8 is a schematic structural diagram of a left SI
`lamp in which the main optical axis is inclined by 45° in
`an S1 lamp portion united with a headlamp portion or a
`fog lamp portion into one body.
`
`Page 8 of 12
`
`

`
`3
`DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`The present invention will be described below in
`more detail with reference to preferred embodiments
`thereof.
`FIG. 1 is a circuit diagram of a vehicular cornering
`lamp system constructed in accordance with a preferred
`embodiment of the present invention. In the drawing,
`reference numeral 1 designates a car battery; 2, a tail
`lamp; 3, a lighting switch; 4R, a right SI lamp; 4L, a left
`SI lamp; 5R, a motor for variably changing the illumi
`nating angle of the right SI lamp 4R; 5L, a motor for
`variably changing the illuminating angle of the left SI
`lamp 4L; 6R, a right lamp illuminating angle sensor for
`outputting a voltage VFBR corresponding to the illumi
`nating angle of the right SI lamp 4R in accordance with
`the rotation of the motor 5R; 6L, a left lamp illuminat
`ing angle sensor for outputting a voltage VFBL corre
`sponding to the illuminating angle of the left SI lamp 4L
`in accordance with the rotation of the motor 5L; 7, a
`steering sensor for outputting a voltage VIN corre
`sponding to the rotation angle of the steering wheel of
`the vehicle, that is, the steering angle of the vehicle (the
`actual relationship between the rotation angle of the
`steering wheel and the steering angle of the vehicle can
`be easily determined without undue experimentation);
`8, an illuminating direction control circuit constituted
`by a right illuminating direction control circuit 8R and
`a left illuminating direction control circuit 8L; 9R, a
`right relay; and 9L, a left relay.
`In this embodiment, each of the lamp illuminating
`angle sensors 6R and 6L and the steering sensor 7 is
`constituted by a variable resistor.
`In the right illuminating direction control circuit 8R,
`reference numeral 8-1R designates a differential ampli
`?er for amplifying the difference between the output
`voltage VpgR of the right lamp illuminating angle sen
`sor 6R and the output voltage V11vof the steering sensor
`7; 8-2R, a differentiator having the frequency character
`40
`istics and ampli?cation factor shown in FIG. 2 and
`which is used for performing detection and inverting
`ampli?cation of the change of an input voltage (output
`voltage VFBR); 8-3R, an adder for performing addition
`and inverting ampli?cation of the output voltage of the
`differential ampli?er 8-1R and the output voltage of the
`differentiator 8-2R; 84R, an inverting ampli?er for
`performing inverting ampli?cation of the output volt
`age of the adder 8-3R with respect to a reference volt
`age Vref corresponding to the illuminating angle (0°)
`when the vehicle is traveling in the straight-ahead di
`rection; 8-5R, a ?rst booster circuit for performing
`power ampli?cation of the output voltage of the adder
`8-3R; 8-6R, a second booster circuit for performing
`power ampli?cation of the output voltage of the invert
`55
`ing ampli?er 84R; 8-7R, an operation mode switching
`circuit; and 8-8R, a lamp on/off circuit.
`The differential ampli?er 8-1R is constituted by an
`operational ampli?er OPlR and resistors R1]; to R4};
`(RIR=R3R, R2R=R4R) and ampli?es the difference
`between VIN and VFBR by a factor RZR/RIR. The dif
`ferentiator 8-2R is constituted by an operational ampli
`?er OPZR, resistors RSR and R6}; and a capacitor CR. In
`the frequency characteristics shown in FIG. 2, as the
`absolute value of the change of the input voltage in
`creases, the differentiator 8-2R generates an output
`voltage having a larger absolute value with respect to
`the reference voltage Vref.
`
`5,404,278
`4
`The adder 8-3R is constituted by an operational am
`pli?er OP3R and resistors R7]; to R9R. The adder 8-3R
`ampli?es the output voltages of the differential ampli—
`?er 8-1R and the differentiator 8-2R by factors
`R9R/R7R and R9R/R8R, respectively, and adds the
`ampli?ed voltages. The inverting ampli?er 84R is con
`stituted by an operational ampli?er OP4Rand resistors
`RIUR t0 R13}; (Rl0R=R11R, R12R=Rl3R). The ?rst
`booster circuit 8-5R is constituted by transistors TrlR
`and Tr2R. The second booster circuit 86R is consti
`tuted by transistors TrSR and Tr4R.
`The operation mode switching circuit 8-7R is consti
`tuted by comparators CPI}; and CPZR, va transistor
`TrSR and resistors R14}; to R19R. The output voltage
`VIN of the steering sensor 7 is fed to respective nonin
`verting input terminals of the comparators CPlR and
`CPZR. A tap voltage Vt); determined by the resistors
`R14}; and R15}; is fed as a comparative reference volt
`age to respective inverting input terminals of the com
`parators CPIR and CPZR. The junction of the resistors
`R18R and R19]; (R183, R19R<<R3R, R412) iS con
`nected to a noninverting input terminal of the opera
`tional ampli?er 0P1 R in the differential ampli?er 8-1R
`by line L1.
`‘
`The lamp on/ off circuit 8-8R is constituted by a com
`parator CP3R, a transistor Tr6R, a diode DR and resis
`tors R201; and RZIR. The output voltage VIN of the
`steering sensor 7 is fed to an inverting input terminal of
`the comparator CP3R. The comparative reference volt
`age VtR is fed to a noninverting input tenninal of the
`comparator CP3R.
`In the circuit con?guration of the right illuminating
`direction control circuit _8R, the output voltage V011; of
`the ?rst booster circuit 8-5R is supplied to one terminal
`of the motor 5R, the output voltage VmR of the second
`booster circuit 8-6R is supplied to the other terminal of
`the motor 9, and the output voltage VCR of the lamp
`on/off circuit 8-8R is supplied to the right relay 9R.
`In the left illuminating direction control circuit 8L,
`the reference numeral 8-1L designates a differential
`ampli?er for amplifying the difference between the
`output voltage VFBL of the left lamp illuminating angle
`sensor 6L and the output voltage VIN of the steering
`sensor 7; 8-2L, a differentiator having the frequency
`characteristics and ampli?cation factor shown in FIG. 2
`and for performing detection and inverting ampli?ca
`tion of the change of an input voltage (output voltage
`VFBL); 8-3L, an adder for performing addition and
`inverting ampli?cation of the output voltage of the
`differential ampli?er 8-1L and the output voltage of the
`differentiator 8~2L; 84L, an. inverting ampli?er for
`performing inverting ampli?cation of the output volt
`age of the adder 8-3L with respect to a reference volt
`age Vref corresponding to the illuminating angle (0")
`when the vehicle is traveling in the straight-ahead di
`rection; 8-5L, a ?rst booster circuit for performing
`power ampli?cation of the output voltage of the adder
`8-3L; 8-6L, a second booster circuit for performing
`power ampli?cation of the output voltage of the invert
`ing ampli?er 84L; 8-7L, an operation mode switching
`circuit; and 8-8L, a lamp_on/off circuit. The respective
`parts,‘ have the same con?guration as corresponding
`parts in the right illuminating direction control circuit
`8R.
`The operation of the inventive cornering lamp system
`will now be described.
`‘
`First, for simpli?cation of description, the basic oper
`ation of the illuminating direction control circuit 8R
`
`65
`
`25
`
`35
`
`45
`
`Page 9 of 12
`
`

`
`5,404,278
`5
`will be described in the case where the operation mode
`switching circuit 8-7R and the lamp on/off circuit 8-8R
`are not provided.
`Assume now the case where the actual illuminating
`angle is coincident with the target illuminating angle
`(0°) because the vehicle is traveling in the straight
`ahead direction, that is, the case where the illuminating
`angle is in the forward direction, so that the difference
`between VFBR and V1Nis zero. In this case, the output
`voltages V011; and V021; of the ?rst and second booster
`circuits 8-5R and 8-6R are both set to 6 V, and the
`motor SR is kept in a stopped state.
`When the increase of VIN from time t1 shown in of
`FIG. 3(a) is started in accordance with rightward steer
`ing from the above-mentioned state, an ampli?cation
`15
`voltage corresponding to the difference between VIN
`and VFBR is obtained from the differential ampli?er
`8-1R (see FIG. 3(b)). The output voltage of the differen~
`tial ampli?er 8-1R and the output voltage of the differ
`entiator 8-2R are added and invertingly ampli?ed by the
`adder 8-3R. At this point of time, the output voltage of
`the differentiator 8-2R is kept at level of the reference
`voltage value Vrefbecause VFBR has not changed yet
`(see FIG. 3(0)). That is, an output voltage formed as the
`result of addition and inverting ampli?cation of the
`output voltage Vmfof the differentiator 8-2R and the
`output voltage of the differential ampli?er 8-1R is ob
`tained from the adder 8-3R, and an output voltage
`formed as a result of further inverting ampli?cation
`thereof is‘ obtained from the inverting ampli?er 84R.
`Accordingly, the output voltage V011; of the ?rst
`booster circuit 8-5R begins to increase, and the output
`voltage V0211 of the second booster circuit 8-6 begins to
`decrease (see FIG. 3(c)). That is, the voltage supplied
`between the opposite terminals of the motor 5R changes
`continuously to increase the voltage difference therebe
`tween, so that the current supplied to the motor 5R
`increases slowly.
`When the voltage difference supplied between the
`opposite terminals of the motor SR is further widened
`40
`so that it reaches time t2, the rotation of the motor 5R
`starts. As a result, the output voltage VFBR begins to
`increase, and the difference between VFBR and VazR
`begins to decrease, so that the output voltages V01R and
`V021; begin to decrease and increase, respectively. That
`45
`is, the voltage supplied between the opposite terminals
`of the motor 5R changes continuously to narrow the
`voltage difference therebetween, so that the current
`supplied to the motor 5R decreases slowly, thus pre
`venting a rapid increase of the rotational speed of the V
`motor 5R.
`At this point of time, the output voltage of the differ
`entiator 8-2R decreases in accordance with the change
`of the output voltage VFBR because the ampli?cation
`factor increases as the change increases. As a result, the
`quantity of addition to the output voltage of the differ
`ential ampli?er 8-1R supplied to the adder 8-3R de
`creases, so that the decrease of the output voltage V01R
`and the increase of the output voltage V021; occur in
`accordance with the quantity of addition. That is, a
`60
`predetermined value is subtracted from the voltage
`supplied between the opposite terminals of the motor
`5R in accordance with the change of the output voltage
`VFBR, so that the value increases as the voltage change
`increases.
`65
`Then, the steering velocity and the motor rotational
`velocity are balanced so that the increase of VFBR fol
`lows the increase of VIN to keep the voltage difference
`
`6
`between the opposite terminals of the motor 5R con
`stant. At this point of time, the change or the output
`voltage VFBR is smaller than that at the time of the
`starting of the rotation of the motor 5R, so that the
`predetermined value to be subtracted from the voltage
`supplied between the opposite terminals of the motor
`SR is set to a smaller value.
`When the change of VIN stops upon the completion
`of the steering operation (at time t3 shown in FIG. 3(a)),
`the difference between VIN and VFBR begins to be nar
`rowed from the previous constant value. As a result, the
`output voltage V01R, which has been supplied as a
`constant voltage value, begins to decrease, and the out
`put voltage VOZR, which has also been supplied as a
`constant voltage value, begins to increase. Accordingly,
`the voltage difference supplied between the opposite
`terminals of the motor 5R changes continuously so as to
`be narrowed, so that the current supplied to the motor
`5R decreases slowly.
`At this point of time, the predetermined value to be
`subtracted from the voltage supplied between the oppo
`site terminals of the motor 5R decreases as the change
`of the output voltage VFBR decreases. As a result, the
`motor SR is lightly braked before the actual illuminat
`ing angle reaches the target illuminating angle, so that
`overshooting due to the force of inertia is avoided.
`Accordingly, the difference between VFBR and VIN is
`set to zero so that the rotation of the motor 5R stops
`soon (at time t4 shown in FIG. 3(a)).
`The operation of the illuminating direction control
`circuit 8R in the case where the operation mode switch
`ing circuit 8-7R and the lamp on/off circuit 8-8R are
`provided will now be described with reference to the
`above-discussed basic operation.
`Consider now the case of rightward steering with
`respect to the position of straight steering as a start
`point. Assuming now that the steering wheel is in the
`position of straight steering, then an output voltage VIN
`(6 V in this embodiment) in accordance with the posi
`tion is obtained from the steering sensor 7. The output
`voltage V jNlS supplied to the differential ampli?er 8-1R
`and also supplied to the operation mode switching cir
`cuit 8-7R.
`In the operation mode switching circuit 8-7R, the
`comparative reference voltage V11; and the output volt
`age VINare compared. Because V1R>V11v, the outputs
`of the comparators CPIR and CPZR are set to the “0”
`level. As a result, the transistor TrSR is switched on, so
`that a tap voltage is produced at the junction of the
`resistors R181? and R19R. The tap voltage is forcedly
`supplied to the noninverting input terminal of the opera
`tional ampli?er OPlR in the differential ampli?er 8-1R
`through line L1. That is, the input voltage V [NR applied
`to the noninverting input terminal of the operational
`ampli?er OPlR is kept constant, irrespective of the
`output voltage VIN of the steering sensor 7. As a result,
`a control mode in which the output voltage VIN of the
`steering sensor 7 has a value corresponding to the illu
`minating angle of 30° in the right direction is set in the
`right illuminating direction control circuit 8R so that
`the illuminating angle is forcedly set to 30° in the right
`direction.
`On the other hand, in the lamp on/off circuit 8-8R,
`the output of the comparator CP3R is opened because
`V1R>V1N. As a result, the transistor Tr6R is switched
`off, so that there is no current supplied to the coil of the
`right relay 9R. Accordingly, the right SI lamp 4R is set
`in a tumed-off state.
`
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`When rightward steering is carried out from the
`after the angle reaches 405°, the right SI lamp 4R is
`above-mentioned state, the output voltage VIN in
`switched off. Accordingly, the lamp is prevented from
`creases. When the steering angle then reaches 0R so that
`being repetitively turned on and off by slight turning of
`V1R<V1N, the outputs of the comparators CPI}; and
`the handle by changing the timing between the start of
`CP2R are opened so that the transistor TrSR is switched
`turn-on and the start of tum-off.
`off to thereby set the junction of the resistors R18}; and
`Further, according to the above characteristics,
`R19}; at a high impedance. Accordingly, in the differen
`when rightward steering is carried out, the illuminating
`tial ampli?er 8-1R, the input voltage VINR to the nonin
`angle of the right SI lamp 4R is ?xed at 30° in the right
`verting input terminal of the operational ampli?er
`ward direction until the steering angle reaches 40.5‘.
`OPlR thereof changes in accordance with the output
`From the point of time the steering angle reaches 40.5",
`voltage of the steering sensor 11 (time t1 FIG. 4(a)), so
`the illuminating angle of the right SI lamp 4R is
`that the V13 illuminating direction of the right SI lamp
`changed in accordance with the steering direction.
`4R changes in accordance with rightward steering from
`When, for example, leftward steering is carried out
`this point of time.
`starting from a steering angle of 120', the illuminating
`On the other hand, in the lamp on/off circuit 8-8R,
`direction is changed at a higher speed than in the case of
`the output of the comparator CPSR is set to the “0”
`rightward steering and then ?xed to 30° in the right
`level because V1R<V1N. As a result, the transistor
`ward direction after the point of time when the steering
`Tr6R is switched on, so that current is supplied to the
`angle reaches 67.5°. That is, according to the above
`coil of the right relay 9R to thereby turn on the right SI
`characteristics, the illuminating direction changing
`lamp 4R.
`speed when leaving a curve is made higher than when
`That is, according to the present invention, the right
`entering the curve road. Accordingly, there is attained
`SI lamp 4R is turned off and the illuminating angle is
`an illuminating direction changing operation which
`?xed to 30° in the rightward direction until the angle of
`follows the eyes’ natural motion where the eyes are
`rightward steering with respect to the position of
`turned more rapidly when entering a curve than when
`straight advance steering reaches 0R. Then, from the
`25
`leaving a curve.
`point of time when the steering angle reaches 0);, the
`Alternatively, in the characteristics shown in FIGS. 5
`right SI lamp 4R is turned on and the illuminating angle
`and 6, the lighting voltage when turning off the lamp
`changes in accordance with the steering direction.
`may be changed within a range of 10% of the voltage at
`When the steering angle is reduced to a smaller value
`the time the lamp is turned on. In this case, the lamp is
`than 0;; because of leftward steering after the steering
`switched on/off slowly, so that a dazzling effect which
`angle reaches 0R, the illuminating angle of the right SI
`might be caused by rapid turning on/ off the lamp can be
`lamp 4R is ?xed to 30° in the rightward direction, and
`prevented.
`the state of the lamp 4R is returned from the on state to
`In the above description, a sub-re?ector moving type
`the off state in accordance with the outputs of the oper
`lamp as shown in FIG. 7 is used for each of the right and
`ation mode switching circuit 8-7R and the lamp on/off
`35
`left SI lamps 4R and 4L. In the drawing, reference
`circuit 8-8R.
`numeral 10 designates a light source; 11, a sub-re?ector
`The same operation as in the right illuminating direc~
`(auxiliary re?ection mirror) rotatably disposed on the
`tion control circuit 8R is carried out in the left illuminat
`rear side of the light source 10; and 12, a main re?ector
`ing direction control circuit 8L. That is, when leftward
`(main re?ection mirror) stationarily disposed on the
`steering with respect to the position of straight-ahead
`rear side of the subre?ector 11. That is, in the above
`steering is carried out, the left SI lamp 4L is turned off
`description, an SI lamp in which the main optical axis
`and the illuminating angle thereof is ?xed to 30° in the
`determined by the main re?ector 12 is stationarily set in
`leftward direction until the angle of leftward steering
`the forward direction (straight-ahead direction) while
`reaches 0],. Then, from the point of time when the
`the auxiliary optical axis de?ned by the sub-re?ector 11
`steering angle reaches 0]_, the left SI lamp 4L is turned
`is changed variably in accordance with the steering
`on and the illuminating angle changes in accordance
`with the steering direction.
`direction is used for the right and left SI lamps 4R and
`FIG. 5 shows illuminating angle changing character
`4L.
`'
`istics (illuminating direction changing characteristics)
`When in such an SI lamp the sub-re?ector 11 is ro
`tated at an angle larger than 30° in the left and right
`and on/o?' characteristics of the right and left SI lamps
`directions with respect to the main optical axis, the
`4R and 4L in accordance with the steering angle. In the
`drawing, I-1 and L2 represent the illuminating direction
`geometrical positional relation between the ?xed beam
`changing characteristic and on/ off characteristics of the
`light source 10 and the movable sub-re?ector 11 is how
`right SI lamp 4R, and II-l and 11-2 represent the illumi
`ever shifted so that there arises a problem in that the
`nating direction changing characteristic and on/off
`main optical axis becomes obscure.
`55
`characteristics of the left SI lamp 4L.
`To solve this, in a left SI lamp 13L having the struc
`ture schematically shown in FIG. 8, an SI lamp portion
`Although the above description relates to the case
`where the illuminating direction changing characteris
`13L-2 united with a headlamp portion or a fog lamp
`tics and the on/ off characteristics of the right and left SI
`portion 13L-1 into one body is provided so that the
`lamps 4R and 4L are as shown in FIG. 5, the invention
`main optical axis Lrn is inclined to the left with respect
`to the forward direction and the auxiliary optical axis
`can be applied to the case where the characteristics are
`as shown in FIG. 6.
`Ls is changed variably in a range of 30° to 75° with
`According to the characteristics, when, for example,
`respect to the forward direction. That is, the illuminat
`the turning angle of the handle reaches 40.5° by right
`ing angle of the SI lamp portion ISL-2 is 45° when the
`ward steering with respect to the position of straight
`main optical axis Lm is coincident with the auxiliary
`ahead steering as a start point, the right-SI lamp 4R is
`optical axis Ls, 30'’ when the auxiliary optical axis Ls is
`switched on. When the steering angle is subsequently
`rotated to the left by 15° with respect to the main opti
`reduced to a smaller value than 27° by leftward steering
`cal axis Lm, and 75° when the auxiliary optical axis Ls
`
`30
`
`60
`
`65
`
`15
`
`45
`
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`is rotated to the left by 30° with respect to the main
`prises a movable re?ector and a motor for moving said
`optical axis Lm.
`movable re?ector.
`Further, in FIG. 8, reference numeral 13L-3 desig
`4. The vehicular cornering lamp system of claim 3,
`nates a lens; 13L-21, a sub-re?ector; 13L-22, a main
`wherein each of said ?rst illuminating direction chang
`re?ector; and ISL-11 and 13L-23, light bulbs.
`ing means and said second illuminating direction chang
`As is evident from the above description, in accor
`ing means comprises:
`dance with the present invention, when the steering
`an illuminating angle sensor for providing a voltage
`angle is in a range from a predetermined value 0L to a
`corresponding to said illuminating direction of the
`predetermined value 6R, each of the left lighting means
`respective one of said right and left illuminating
`and the right lighting means is on standby in a tumed
`means;
`off state while the illuminating directions thereof are set
`a steering sensor for providing a voltage correspond
`respectively to predetermined angles in the left and
`ing to said steering angle;
`right directions of the vehicle. When the steering angle
`a differential ampli?er receiving as differential inputs
`