United States Patent [19]
`Miyauchi et al.
`
`[11] Patent Number:
`[45] Date of Patent:
`
`4,868,720
`Sep. 19, 1989
`
`[54] ROAD SURFACE-SENSITIVE BEAM
`PATTERN LEVELING SYSTEM FOR A
`VEHICLE HEADLAMP
`[75] Inventors: Shizuya Miyauchi; Kiyoshi Wada,
`both of Shimizu, Japan
`[73] Assignee: Koito Seisakusho Co., Ltd., Shizuoka,
`Japan
`[21] Appl. No.: 206,449
`[22] Filed:
`Jun. 14, 1988
`[30]
`Foreign Application Priority Data
`Aug. 17, 1987 [JP]
`Japan ................................ 62-203804.
`[51] Int. Cl." ......... ~~~~ B600 1/10, B600 11/00;
`B62J 6/00
`[52] U.S. Cl. ….. 362/69; 362/71;
`-
`362/72; 362/287
`[58] Field of Search ....................... 362/66, 69, 71, 72,
`362/285, 287, 429
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`3,939,339 2/1976 Alphen .................................. 362/72
`4,075,469 2/1978 Alphen .................................. 362/72
`4,204,270 5/1980 Poirier d’Ang d'Orsay ........ 362/71
`4,223,375 9/1980 Alphen .................................. 362/72
`4,237,524 12/1980 Hundemer ...
`.... 362/71
`4,583,152 4/1986 Kawai et al. .......................... 362/71
`4,620,267 10/1986 Cibie .............
`362/66 X
`4,733,334 3/1988 Krey ..................................... 362/71
`
`FOREIGN PATENT DOCUMENTS
`5618430 4/1981 Japan .
`Primary Examiner—Ira S. Lazarus
`Assistant Examiner—Richard R. Cole
`Attorney, Agent, or Firm—Sughrue, Mion, Zinn,
`Macpeak & Seas
`ABSTRACT
`[57]
`A motorcycle headlamp capable of emitting a light
`beam with a beam pattern calculated to provide opti
`mum forward illumination. In order to maintain the
`beam pattern in a level position about the lamp axis
`despite the lateral tipping of the motorcycle, at least one
`road sensor is employed for detecting the lateral angu
`lar position of the vehicle with respect to the road sur
`face by transmitting radiation such as an ultrasonic
`wave or infrared rays toward the road surface and re
`ceiving its reflection from the road surface. Electric
`signals representative of lateral vehicle inclinationare
`fed to a central processor unit, which then causes ener
`gization of a reversible electric motor built into the
`headlamp unit for leveling the beam pattern by revolv
`ing the bulb and control lens of the headlamp unit rela
`tive to the lamp housing. Thus, as the lateral angular
`position of the vehicle is detected in reference to the
`road surface, instead of to the perpendicular, the beam
`pattern can be maintained in the level position with
`respect to the road surface regardless of whether the
`road is banked or unbanked. Several different methods
`of detecting lateral vehicle inclination are disclosed.
`
`17 Claims, 20 Drawing Sheets
`
`
`
`SL Corporation v. Adaptive Headlamp Technologies, Inc.
`
`
`
`SL Corp. Exhibit 1040
`Case IPR2016-00193
`
`

`
`U.S. Patent
`U.S. Patent
`
`Sep. 19, 1989
`Sep.19,1989
`
`Sheet 1 of 20
`Sheet 1 of 20
`
`4,868,720
`4,868,720
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`U.S. Patent Sep.19, 1989
`U.S. Patent
`Sep. 19,1989
`
`Sheet 2 of 20
`Sheet 2 of 20
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`4,868,720
`4,868,720
`
`
`
`

`
`U.S. Patent Sep.19, 1989
`U.S. Patent
`Sep. 19,1989
`
`Sheet 3 of 20
`Sheet 3 of 20
`
`4,868,720
`4,868,720
`
`Fig. 3
`Fig. 3
`
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`

`
`U.S. Patent Sep.19, 1989
`U.S. Patent
`Sep. 19, 1989
`
`Sheet 4 of 20
`Sheet 4 of 20
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`4,868,720
`4,868,720
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`U.S. Patent Sep.19, 1989
`U.S. Patent
`Sep. 19,1989
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`Sheets of 20
`Sheet 5 of 20
`
`4,868,720
`4,868,720
`
`Fig. 5
`Fig.5
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`

`
`U.S. Patent Sep.19, 1989
`U.S. Patent
`Sep.19,1989
`
`Sheet 6 of 20
`Sheet 6 of 20
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`4,868,720
`4,868,720
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`
`
`

`
`U.S. Patent
`Sep. 19, i939
`U.S. Patent Sep.19, 1989
`
`Sheet 7 of 20
`Sheet 7 of 20
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`4,868,720
`4,868,720
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`U.S. Patent Sep. 19, 1989
`U.S. Patent
`Sep.19,1989
`
`Sheet 8 of 20
`Sheet 8 of 20
`
`4,868,720
`4,868,720
`
`Fig. 10
`Fig.1O
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`

`
`Sheet 9 of 20
`U.S. Patent Sep.19, 1989
`Sheet 9 of 20
`U.S. Patent
`Sep. 19, 1939
`Fig. 11 A
`Fig.11A
`
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`
`4,868,720
`4,868,720
`
`

`
`U.S. Patent Sep.19, 1989
`U.S. Patent
`Sep. 19, 1939
`
`Sheet 10 of 20
`Sheet 10 of 20
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`4,868,720
`4,868,720
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`Sep. 19, 1989
`Sep.19,1989
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`Sheet 11 of 20
`Sheet 11 of 20
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`U.S. Patent Sep.19, 1989
`U.S. Patent
`Sep.19,1989
`
`Sheet 12 of 20
`Sheet 12 of 20
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`4,868,720
`4,868,720
`
`Fig. 18
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`
`U.S. Patent
`U.S. Patent
`
`Sep.19, 1989
`Sep. 19,1939
`
`Sheet 13 of 20
`Sheet 13 of 20
`
`4,868,720
`4,868,720
`
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`
`U.S. Patent Sep.19, 1989
`U.S. Patent
`Sep.19,1989
`
`Sheet 14 of 20
`Sheet 14 of 20
`
`4,868,720
`4,868,720
`
`Fig. 20
`Fig. 20
`
`( A ) CLOCK SIGNAL —TH
`(,4) c1_oc/v 3/G/VAL
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`(B) 0SCILLATOR OUTPUT —|||——
`( B) OSCILLATOR OUTPUT fiM
`(C) Ul?A$9N?. WAVE —WW--
`(C) ULTRASONIC WAVE —vMwNN
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`(E) PREAMP OUTPUT --?–
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`( G ) T W G OUTPUT ? (WITH NOISE)
`
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`( H ) DETECTOR OUTPUT —TN—
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`( I ) ADC output — —
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`_____f_L:__
`
`

`
`U.S. Patent
`U.S. Patent
`
`Sep..19,1989
`
`Sheet 15 of 20
`
`4,868,720
`4,868,720
`
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`
`U.S. Patent Sep.19, 1989
`U.S. Patent
`Sep.19,1989
`
`Sheet 16 of 20
`Sheet 16 of 20
`
`4,868,720
`4,868,720
`
`Fig. 23
`Fig.23
`
`.
`ONE SCANNING CYCLE
`ONE SCANNING CYCLE
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`

`
`U.S. Patent Sep. 19, 1989
`U.S. Patent
`Sep.19,1989
`
`Sheet 17 of 20
`Sheet 17 of 20
`
`4,868,720
`4,868,720
`
`
`
`

`
`U.S. Patent Sep.19, 1989
`U.S. Patent
`Sep. 19,1989
`
`Sheet 18 of 20
`Sheet 18 of 20
`
`4,868,720
`4,868,720
`
`Fig. 26
`Fig. 26
`
`
`
`

`
`U.S. Patent Sep. 19, 1989
`U.S. Patent
`Sep.19,1989
`
`Sheet 19 of 20
`Sheet 19 of 20
`
`4,868,720
`4,868,720
`
`
`
`

`
`U.S. Patent Sep.19, 1989
`U.S. Patent
`Sep. 19,1989
`
`Sheet 20 of 20
`Sheet 20 of 20
`
`4,868,720
`4,868,720
`
`Fig. 29
`Fig.29
`
`
`
`
`

`
`1
`1
`ROAD SURFACE-SENSITIVE BEAM PATTERN
`ROAD SURFACE-SENSITIVE BEAM PATTERN
`LEVELING SYSTEM FOR A VEHICLE
`LEVELING SYSTEM FOR A VEHICLE
`HEADLAMP
`HEADLAMP
`
`4,868,720
`4,868,720
`2
`2
`workability has proved to be very inconvenient because
`workability has proved to be very inconvenient because
`road surfaces are not necessary horizontal in their trans
`road surfaces are not necessary horizontal in their trans-
`verse direction. Curves in highways in particular are
`verse direction. Curves in highways in particular are
`usually banked; that is, they tilt laterally upward from
`usually banked; that is, they tilt laterally upward from
`the inside edge to the outside edge so as to help vehicles
`the inside edge to the outside edge so as to help vehicles
`smoothly round the curves without the possibility of
`smoothly round the curves without the possibility of
`being centrifugally carried off the track.
`being centrifugally carried off the track.
`Let us suppose that the motorcycle with the prior art
`Let us suppose that the motorcycle with the prior art
`beam pattern leveling system is taking a banked curve,
`beam pattern leveling system is taking a banked curve,
`with the vehicle laterally slanting out of the perpendicu
`with the vehicle laterally slanting out of the perpendicu-
`lar and into right angular relationship with the roadbed.
`lar and into right angular relationship with the roadbed.
`Since the vehicle is then at an angle to the perpendicu
`Since the vehicle is then at an angle to the perpendicu-
`lar, the prior art system will detect this angle gyroscopi
`lar, the prior art system will detect this angle gyroscopi-
`cally and correspondingly readjust the beam pattern
`cally and correspondingly readjust the beam pattern
`into an angled position with respect to the bank. Such
`into an angled position with respect to the bank. Such
`readjustment is unnecessary or, indeed, undesirable.
`readjustment
`is unnecessary or,
`indeed, undesirable.
`The beam pattern should have stayed in the level posi
`The beam pattern should have stayed in the level posi-
`tion with respect to the slanting road surface, just as
`tion with respect to the slanting road surface, just as
`when the vehicle is running an unbanked road.
`when the vehicle is running an unbanked road.
`SUMMARY OF THE INVENTION
`SUMMARY OF THE INVENTION
`We have hereby succeeded in overcoming the noted
`We have hereby succeeded in overcoming the noted
`weakness of the prior art and in providing a truly satis
`weakness of the prior art and in providing a truly satis-
`factory beam pattern leveling system which is respon
`factory beam pattern leveling system which is respon-
`sive to the lateral tipping of the vehicle with respect to
`sive to the lateral tipping of the vehicle with respect to
`the road surface rather than to the perpendicular.
`the road surface rather than to the perpendicular.
`Our invention may be summarized as a beam pattern
`Our invention may be summarized as a beam pattern
`leveling headlamp system for use on a motorcycle or
`leveling headlamp system for use on a motorcycle or
`like vehicle that is subject to lateral tipping as when
`like vehicle that is subject to lateral tipping as when
`taking a curve, comprising a headlamp unit on the vehi
`taking a curve, comprising a headlamp unit on the vehi-
`cle for emitting a light beam having a prescribed beam
`cle for emitting a light beam having a prescribed beam
`pattern, the headlamp unit being capable of angularly
`pattern, the headlamp unit being capable of angularly
`displacing the beam pattern about the lamp axis. The
`displacing the beam pattern about the lamp axis. The
`headlamp unit is provided with beam pattern leveling
`headlamp unit is provided with beam pattern leveling
`means acting thereon for causing the headlamp unit to
`means acting thereon for causing the headlamp unit to
`angularly displace the beam pattern about the lamp axis.
`angularly displace the beam pattern about the lamp axis.
`The headlamp system further comprises vehicle inclina
`The headlamp system further comprises vehicle inclina-
`tion detector means sensitive to a“road surface on which
`tion detector means sensitive to a road surface on which
`the vehicle is traveling, for detecting the degree of
`the vehicle is traveling, for detecting the degree of
`lateral tipping of the vehicle with respect to the road
`lateral tipping of the vehicle with respect to the road
`surface. In response to signals from the vehicle inclina
`surface. In response to signals from the vehicle inclina-
`tion detector means, control means actuates the beam
`tion detector means, control means actuates the beam
`pattern leveling means so as to cause the head lamp unit
`pattern leveling means so as to cause the head lamp unit
`to angularly displace the beam pattern about the lamp
`to angularly displace the beam pattern about the lamp
`axis to an extent necessary for leveling the beam pattern
`axis to an extent necessary for leveling the beam pattern
`in the face of the lateral tipping of the vehicle out of the
`in the face of the lateral tipping of the vehicle out of the
`right angular relationship to the road surface.
`right angular relationship to the road surface.
`According to more specific aspects of our invention,
`According to more specific aspects of our invention,
`the vehicle inclination detector means comprises at least
`the vehicle inclination detector means comprises at least
`one road sensor which transmits some radiation, such as
`one road sensor which transmits some radiation, such as
`an ultrasonic wave or infrared rays, toward the road
`an ultrasonic wave or infrared rays, toward the road
`surface and which receives the reflection of the radia-
`surface and which receives the reflection of the radia
`tion from the road surface. One or two such road sen-
`tion from the road surface. One or two such road sen
`sors may be employed in combination with the same
`sors may be employed in combination with the same
`number of angle sensor or sensors. By oscillating the
`number of angle sensor or sensors. By oscillating the
`road sensor or sensors transversely of the road while the
`road sensor or sensors transversely of the road while the
`vehicle is running, there can be obtained signals repre
`vehicle is running, there can be obtained signals repre-
`sentative of the direction (either rightward or leftward
`sentative of the direction (either rightward or leftward
`of the vehicle) and angle of the lateral tipping of the
`of the vehicle) and angle of the lateral tipping of the
`vehicle with respect to the road surface. Alternatively,
`vehicle with respect to the road surface. Alternatively,
`a greater number of road sensors may be fixedly
`a greater number of road sensors may be fixedly
`mounted to the vehicle in suitable arrangement for pro
`mounted to the vehicle in suitable arrangement for pro-
`viding such signals.
`viding such signals.
`Thus, as the lateral inclination of the vehicle is de-
`Thus, as the lateral inclination of the vehicle is de
`tected with respect to the road surface, instead of to the
`tected with respect to the road surface, instead of to the
`perpendicular, in accordance with our invention, the
`perpendicular, in accordance with our invention, the
`beam pattern can always be maintained in the level
`beam pattern can always be maintained in the level
`
`BACKGROUND OF THE INVENTION
`BACKGROUND OF THE INVENTION
`Our invention relates generally to vehicular head
`Our invention relates generally to vehicular head-
`lamps and more specifically to those suitable for use on
`lamps and more specifically to those suitable for use on
`motorcycles or like vehicles that tilt laterally as when
`motorcycles or like vehicles that tilt laterally as when
`10
`10
`taking a curve or bend in a road. Still more specifically,
`taking a curve or bend in a road. Still more specifically,
`our invention pertains to a system for use with such
`our invention pertains to a system for use with such
`vehicular headlamps for automatically maintaining the
`vehicular headlamps for automatically maintaining the
`pattern of the light beam, particularly the lower beam,
`pattern of the light beam, particularly the lower beam,
`thrown thereby in a level position about the beam axis
`thrown thereby in a level position about the beam axis
`in the face of variations in the lateral angle of the vehi
`in the face of variations in the lateral angle of the vehi-
`cle with respect to the road surface.
`cle with respect to the road surface.
`Vehicle headlamps today are usually constructed to
`Vehicle headlamps today are usually constructed to
`provide the so called “upper beam” and “lower beam”.
`provide the so called “upper beam” and “lower beam”.
`The upper beam is intended primarily for distant illumi
`The upper beam is intended primarily for distant illumi-
`20
`20
`nation when the vehicle is not meeting or following
`nation when the vehicle is not meeting or following
`other vehicles. The lower beam is intended to illuminate
`other vehicles. The lower beam is intended to illuminate
`the road ahead of the vehicle when it is meeting or
`the road ahead of the vehicle when it is meeting or
`following another vehicle. The pattern or cross sec
`following another vehicle. The pattern or cross sec-
`tional shape of the lower beam, in particular, is defi
`tional shape of the lower beam, in particular, is defi-
`25
`nitely determined (see FIG. 10 of the drawing attached
`25
`nitely determined (see FIG. 10 of the drawing attached
`hereto) for the dual purpose of providing optimum road
`hereto) for the dual purpose of providing optimum road
`illumination for safe driving and of protecting other
`illumination for safe driving and of protecting other
`drivers from glare.
`drivers from glare.
`A problem has been encountered in connection with
`A problem has been encountered in connection with
`30
`such two beam headlamps on motorcycles or like two
`30
`such two beam headlamps on motorcycles or like two
`wheeled vehicles. The vehicles of this class must tilt
`wheeled vehicles. The vehicles of this class must tilt
`laterally when taking a curve or bend in a road, in order
`laterally when taking a curve or bend in a road, in order
`to avoid being centrifugally carried off the road or
`to avoid being centrifugally carried off the road or
`toppling over. As the vehicle tips in either of the oppo
`toppling over. As the vehicle tips in either of the oppo-
`35
`site lateral directions, so does the pattern of the lower
`35
`site lateral directions, so does the pattern of the lower
`beam emitted by its headlamp. Thus angularly displaced
`beam emitted by its headlamp. Thus angularly displaced
`from its level position, the lower beam pattern fails to
`from its level position, the lower beam pattern fails to
`perform its intended functions, illuminating the road
`perform its intended functions, illuminating the road
`either too close to, or too far away from, the vehicle, or
`either too close to, or too far away from, the vehicle, or
`not illuminating its lane at all, and possibly dazzling the
`not illuminating its lane at all, and possibly dazzling the
`drivers of oncomming vehicles.
`drivers of oncomming vehicles.
`Miyauchi et al. U.S. patent application Ser. No.
`Miyauchi et al. U.S. patent application Ser. No.
`07/137,021, pending filed Dec. 22, 1987, represents an
`07/137,021, pending filed Dec. 22, 1987, represents an
`attempted solution to the above stated problem. This
`attempted solution to the above stated problem. This
`45
`prior application teaches a motorcycle headlamp unit
`prior application teaches a motorcycle headlamp unit
`45
`wherein the bulb and the control lens are rigidly inter
`wherein the bulb and the control lens are rigidly inter-
`connected for joint bidirectional rotation, within limits,
`connected for joint bidirectional rotation, within limits,
`about the lamp axis with respect to the lamp housing,
`about the lamp axis with respect to the lamp housing,
`thereby making possible the angular displacement of the
`thereby making possible the angular displacement of the
`50
`beam pattern about the lamp axis. It also suggests a
`beam pattern about the lamp axis. It also suggests a
`50
`gyroscopic vehicle inclination detector for detecting
`gyroscopic vehicle inclination detector for detecting
`the lateral, as well as longitudinal, tilting of the motor
`the lateral, as well as longitudinal, tilting of the motor-
`cycle with respect to the perpendicular. As an electric
`cycle with respect to the perpendicular. As an electric
`output signal of the detector indicates the lateral tilting
`output signal of the detector indicates the lateral tilting
`of the vehicle in either direction, the interconnected
`of the vehicle in either direction, the interconnected
`bulb and control lens of the headlamp unit is revolved in
`bulb and control lens of the headlamp unit is revolved in
`the required direction to such an extent that the beam
`the required direction to such an extent that the beam
`pattern is maintained level about the lamp axis despite
`pattern is maintained level about the lamp axis despite
`the vehicle tipping.
`the vehicle tipping.
`We have found this known beam pattern leveling
`We have found this known beam pattern leveling
`system unsatisfactory because of the use of the gyro
`system unsatisfactory because of the use of the gyro-
`scopic vehicle inclination detector. Operating gyro
`scopic vehicle inclination detector. Operating gyro-
`scopically, the prior art vehicle inclination detector can
`scopically, the prior art vehicle inclination detector can
`find the lateral vehicle angle with respect to the perpen
`find the lateral vehicle angle with respect to the perpen-
`65
`dicular and not to the road surface on which the vehicle
`dicular and not to the road surface on which the vehicle
`65
`is traveling. For this reason the known leveling system
`is traveling. For this reason the known leveling system
`works well only as long as the vehicle is running on a
`works well only as long as the vehicle is running on a
`road surface that is horizontal transversely. This limited
`road surface that is horizontal transversely. This limited
`
`15
`15
`
`55
`55
`
`

`
`3
`position required by the lateral angle between the vehi-
`cle and the road surface. We are using the term “level
`position” of the light beam in reference to the transverse
`angle of the road surface which, of course, is not neces-
`sarily horizontal. When the road is banked, the vehicle 5
`will naturally incline out of the perpendicular into right
`angular relation with the road surface. Then the beam
`pattern will be in the “level position” with respect to
`the road surface even though it will be at an angle to the
`horizon. Thus our invention will contribute materially
`to safe driving on both banked and unbanked roads in
`the nighttime through enhancement of forward visibil-
`ity and reduction of glare.
`The above and other features and advantages of our
`invention and the manner of realizing them will become
`more apparent, and the invention itself will best be
`understood, from a study of the following description
`and appended claims, with reference had to the at-
`tached drawings showing some preferable embodiments
`of the invention.
`
`l0
`
`15
`
`20
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`25
`
`30
`
`FIG. 1 is a block diagram showing the general con-
`figuration of the road surface sensitive beam pattern
`leveling system in accordance with our invention;
`FIG. 2 is a top plan of the motorcycle headlamp
`assembly suitable for use with the beam pattern leveling
`system of our invention;
`FIG. 3 is a side elevation of the headlamp assembly of
`FIG. 2;
`FIG. 4 is an axial section through the headlamp as-
`sembly, taken along the line IV——IV in FIG. 2;
`FIG. Sis a perceptive view showing in particular the
`interconnected bulb and control lens of the headlamp
`assembly which are jointly rotatable relative to the 35
`lamp housing in order to revolve the beam pattern
`about the lamp axis;
`FIG. 6 is an enlarged perspective view of the bulb of
`the headlamp assembly;
`FIG. 7 is an enlarged end elevation of the bulb shown 40
`together with the connector, by which the bulb is con-
`nected to the control lens as best seen in FIG. 5, and
`means for mounting the bulb to the connector in the
`correct angular position about the lamp axis;
`FIG. 8 is a transverse section through the shield cap
`of the bulb, taken along the line VIII—VIII in FIG. '6
`and explanatory of how the lower beam of the desired
`pattern is emitted by the bulb;
`FIG. 9 is a diagram the lower beam pattern produced
`by the bulb having the shield cap of FIG. 8;
`FIG. 10 is a more concrete illustration of the pattern
`of the lower beam emitted by the bulb, the lower beam
`pattern being shown as actually thrown on the road on
`which the motorcycle is traveling;
`FIG. 11A is a end elevation of the motorcycle, to-
`gether with a rider thereon, incorporating the beam
`pattern leveling headlamp system of our invention, the
`view being explanatory of how the lateral vehicle angle
`is detected with respect to the road surface when the
`vehicle is traveling in an upstanding attitude or at right
`angles with the road surface;
`'
`FIG. 11B is an illustration similar to FIG. 11A and
`explanatory of how the lateral vehicle angle is detected
`with respect to the road surface when the vehicle is
`running at an angle thereto;
`FIG. 12 is a section through the vehicle inclination
`detector, forming a part of the beam pattern leveling
`headlamp system of our invention, for detecting the
`
`45
`
`50
`
`55
`
`65
`
`4,868,720
`
`4
`lateral angle of the vehicle with respect to the road
`surface, the section being taken along a vertical plane
`transverse to the motorcycle to which the detector is
`mounted;
`FIG. 13 is a section through the vehicle inclination
`detector of FIG. 12, taken along the line XIII—XIII in
`FIG. 12;
`FIG. 14 is an exploded perspective view of the road
`sensor, "angle sensor, and road sensor drive motor in-
`cluded in the vehicle clination detector of FIGS. 12 and
`13;
`FIG. 15 is a vertical section through a modified vehi-
`cle inclination detector in accordance with our inven-
`tion;
`FIG. 16 is a vertical section through another modi-
`fied vehicle inclination detector in accordance with our
`invention;
`FIG. 17 is a section through the vehicle inclination
`detector of FIG. 16, the section being taken along the
`line XVII—XVII in FIG. 16;
`FIG. 18 is a block diagram of the general electrical
`configuration of the beam pattern leveling headlamp
`system in accordance with our invention;
`FIG. 19 is a block diagram showing in more detail the
`electric circuitry associated with the road sensor used in
`any of the three different forms of the vehicle inclina-
`tion detector shown in FIGS. 12-17;
`FIG. 20 is a diagram of waveforms appearing in the
`various parts of the road sensor circuitry of FIG. 19, the
`waveforms being useful in explaining the operation of
`the road sensor circuitry;
`FIG. 21 is a schematic electrical diagram, partly in
`block form, of the circuitry for controllably driving the
`reversible electric motor of the beam pattern leveling
`mechanism incorporated with the headlamp assembly
`of FIGS. 2-4;
`FIG. 22 is a schematic electrical diagram, partly in
`block form, of the circuitry associated with the angle
`sensor used in any of the three different forms of the
`vehicle inclination detector shown in FIGS. 12-17;
`FIG. 23 is a waveform diagram showing signals use-
`ful in explaining how the direction and angle of lateral
`tipping of the vehicle are ascertained from the output
`signals of the angle sensor circuitry of FIG. 22 and the
`road sensor circuitry of FIG. 19;
`FIG. 24 is a side elevation of a motorcycle, shown
`together with a rider thereon, having a pair of vehicle
`inclination detectors mounted thereto as an alternative
`
`means for detecting the lateral tipping of the vehicle
`with respect to the road surface;
`FIG. 25 is a schematic illustration of how the pair of
`vehicle inclination detectors of FIG. 24 scan the road
`surface for the detection of lateral vehicle inclination;
`FIG. 26 is a schematic illustration of how the pair of
`vehicle inclination detectors of FIG. 24 detects the
`
`lateral tipping of the vehicle when it is rounding a right-
`ward curve;
`FIG. 27 is a front elevation of a motorcycle, shown
`together with a rider thereon, having a plurality of road
`sensors mounted thereto as a second alternative means
`for detecting the lateral tipping of the vehicle with
`respect to the road surface, the view being explanatory
`of the arrangement of the road sensors as seen from the
`front of the motorcycle;
`FIG. 28 is a side elevation of the motorcycle of FIG.
`27, the view being explanatory of the arrangement of
`the road sensors as seen from the side of the vehicle; and
`
`

`
`15
`15
`
`30
`30
`
`4,868,720
`4,868,720
`6
`6
`5
`5
`26 and control lens 30 are jointly rotatable within limits
`FIG. 29 is a rear elevation of the motorcycle of
`FIG. 29 is a rear elevation of the motorcycle of
`26 and control lens 30 are jointly rotatable within limits
`in both directions about the lamp axis x–x with respect
`FIGS. 27 and 28, the vehicle being shown inclined in
`in both directions about the lamp axis x-—x with respect
`FIGS. 27 and 28, the vehicle being shown inclined in
`to the lamp housing 24 and reflector 28 for the lateral
`order to explain how such vehicle inclination is de
`to the lamp housing 24 and reflector 28 for the lateral
`order to explain how such vehicle inclination is de-
`leveling of the pattern of the beam emitted by the lamp
`tected by the road sensors.
`tected by the road sensors.
`leveling of the pattern of the beam emitted by the lamp
`unit 23.
`unit 23.
`DESCRIPTION OF THE PREFERRED
`DESCRIPTION OF THE PREFERRED
`Both FIGS. 4 and 5 reveal the noted beam pattern
`Both FIGS. 4 and 5 reveal the noted beam pattern
`EMBODIMENTS
`EMBODIMENTS
`leveling mechanism 16, including a reversible electric
`leveling mechanism 16, including a reversible electric
`1. General
`1. General
`motor 34, which is compactly accommodated in the
`motor 34, which is compactly accommodated in the
`space bounded between the lamp housing 24 and the
`We will now describe the road surface sensitive beam
`space bounded between the lamp housing 24 and the
`We will now describe the road surface sensitive beam
`10
`reflector 28. We will refer to the motor 34 as the level-
`10
`reflector 28. We will refer to the motor 34 as the level
`pattern leveling system of our invention in detail as
`pattern leveling system of our invention in detail as
`ing motor in contradistinction from other motors to be
`adapted for use with a motorcycle headlamp. The gen
`ing motor in contradistinction from other motors to be
`adapted for use with a motorcycle headlamp. The gen-
`set forth subsequently. The leveling mechanism 16 acts
`eral organization of the leveling system will become
`set forth subsequently. The leveling mechanism 16 acts
`eral organization of the leveling system will become
`in this embodiment to bidirectionally revolve the bulb
`apparent from its block diagrammatic representation in
`in this embodiment to bidirectionally revolve the bulb
`apparent from its block diagrammatic representation in
`26 and control lens 30 about the lamp axis x—x for
`FIG. 1. The leveling system has a central processor unit
`26 and control lens 30 about the lamp axis x——-x for
`FIG. 1. The leveling system has a central processor unit
`maintaining the beam pattern in the level position with
`(CPU) or very small computer 10, commercially avail
`maintaining the beam pattern in the level position with
`(CPU) or very small computer 10, commercially avail-
`able in the form of a microprocessor on an integrated
`respect to the road surface despite the lateral tipping of
`able in the form of a microprocessor on an integrated
`respect to the road surface despite the lateral tipping of
`circuit chip, for performing the various processing and
`the motorcycle. Seen in the same figures, the aforesaid
`the motorcycle. Seen in the same figures, the aforesaid
`circuit chip, for performing the various processing and
`control functions hereinafter set forth. Connected to the
`beam pattern angle detector 14 functions to detect the
`control functions hereinafter set forth. Connected to the
`beam pattern angle detector 14 functions to detect the
`CPU 10 is, first of all, a vehicle inclination detector 12
`lateral inclination of the beam pattern on the basis of the
`CPU 10 is, first of all, a vehicle inclination detector 12
`lateral inclination of the beam pattern on the basis of the
`20
`for detecting the lateral angular position of the vehicle
`20
`angular displacement of the bulb 26 and control lens 30
`for detecting the lateral angular position of the vehicle
`angular displacement of the bulb 26 and control lens 30
`with respect to the road surface and, if the vehicle is
`with respect to the nonrotatable parts of the lamp unit
`with respect to the road surface and, if the vehicle is
`with respect to the nonrotatable parts of the lamp unit
`laterally inclined out of the right angular relation with
`23.
`laterally inclined out of the right angular relation with
`23.
`the road surface, the direction and angle of the inclina
`the road surface, the direction and angle of the inclina-
`The headlamp assembly 22 further includes a vertical
`The headlamp assembly 22 further includes a vertical
`tion. A beam pattern angle detector 14 is also connected
`tion. A beam pattern angle detector 14 is