Vehicle lamp and vehicle lamp control method

Abstract

The headlamp comprises: a lighting control unit (52) for controlling the emission timing of light emitted from a light source (31); and a rotation scanning unit (32) for repeatedly scanning the light of the light source while rotating, and illuminating a used area with the scanned light. The rotation scanning unit performs multiple repeated scans when rotating one circle. The lighting control unit comprises: a cycle detection unit (524) for detecting the rotation cycle of the rotation scanning unit; and a cycle division unit (525) for equally dividing the rotation cycle and controlling the emission timing of the light source. The lighting control unit controls the emission timing of the light source based on the rotation cycle and the divided cycle.

Description

Technical Field

[0001] The present invention relates to a vehicle lamp that performs light scanning illumination and a method for controlling the vehicle lamp. Background Art

[0002] The following technology is known, that is, detecting objects such as preceding vehicles, oncoming vehicles, pedestrians, etc. in the area in front of the car, and performing light distribution control so that the detected objects do not cause dazzle. For example, the ADB (Adaptive Driving Beam) light distribution control of the car is to control the light distribution so that when illuminating the area above the light-dark cutoff line of the low beam light distribution, the light distribution is selectively not illuminated. The ADB light distribution control uses a light scanning lamp.

[0003] As a vehicle lamp for performing light scanning, the following headlight is known, which uses a scanning mirror that changes the irradiation direction of light emitted from a light source while performing light irradiation. For example, the headlight of Patent Document 1 has a rotating mirror (rotating reflector) that reflects light from the light source as a scanning mirror, and the rotating mirror is driven to rotate by a motor, thereby changing the reflection angle at the rotating mirror, changing the light irradiation direction, and performing light scanning.

[0004] Patent Document 1: International Publication No. 2016 / 104319

[0005] Patent document 2: Japanese Patent Application Laid-Open No. 2020-026170 Summary of the invention

[0006] When controlling the light scanning implemented by the rotating mirror, it is required to detect the rotation position of the rotating mirror and control the rotation of the motor based on the detected rotation position. Patent document 1 discloses the following technologies as technologies for detecting the rotation position of the rotating mirror, namely, a technology for detecting the position of the reflection sheet (light reflection blade) of the rotating mirror and a technology for detecting the rotation position of the motor using a Hall element. Patent document 1 does not record a detailed description of the specific structure of these position detectors. The former technology is speculated to be a technology for detecting the position of the reflection sheet using a photointerrupter, etc., and the latter technology is speculated to be a technology for detecting the magnetic pole position of a magnet constituting the rotor of the motor.

[0007] In the technology using a position detector such as a photointerrupter, it is necessary to arrange the position detector near the reflector of the rotating mirror. This position detector is difficult to miniaturize, and it is necessary to ensure a space for arranging the position detector near the rotating mirror, so it is difficult to miniaturize the rotating mirror. In addition, position detectors such as photointerrupters are generally expensive, so it is difficult to reduce the price of the rotating mirror.

[0008] On the other hand, in the technology using the Hall element, the Hall element is small and relatively cheap, so it is easy to achieve miniaturization and low price of the rotating mirror. However, the Hall element detects the rotation position of the motor, so if there is a positional offset in the rotation direction between the motor and the reflector installed on the motor, a detection error sometimes occurs between the detected rotation position and the actual rotation position of the rotating mirror. In particular, if there is a fluctuation in the position of the S pole and the N pole of the magnet of the motor in the rotation direction, the fluctuation directly becomes a detection error. If the detection error as described above occurs, it is difficult to perform high-precision optical scanning of the rotating mirror even if the rotation of the motor is accurately controlled.

[0009] In addition, in Patent Document 1, when realizing the lighting of the desired area under ADB light distribution control, it is necessary to match the light emission of the light source with the rotation timing of the rotating mirror. If the rotating mirror starts to rotate in accordance with the timing of the ADB light distribution control, the lighting flickers accompanying the change of the motor rotation speed during the rise time from the start of the motor to the stabilization of the rotation speed. As a result, in Patent Document 1, the light distribution characteristics are degraded, causing the driver to feel a sense of disharmony and discomfort.

[0010] In addition, if the rotation of the rotating mirror is stopped when the ADB light distribution control is not performed, the viscosity of the lubricating oil of the bearings of the motor, such as ball bearings and sliding bearings, changes during the stop period. The lubricity may be reduced and the life of the bearings may be shortened. In particular, if the rotating mirror is stopped when the lamp is turned on by the low beam light distribution, the temperature of the headlights accompanying the lighting increases, which has a negative impact on the lubricating oil.

[0011] Patent Document 2 continues to rotate the rotating mirror even when the ADB light distribution control stops. As described above, if the rotating mirror is continuously rotated, the lubricity of the lubricating oil can be suppressed from decreasing. However, Patent Document 2 always rotates the rotating mirror at a predetermined rotation speed, that is, the rotation speed when the ADB light distribution control is performed. Therefore, if the lighting time of the headlight becomes longer, the total number of rotations of the rotating mirror increases and the wear of the motor bearings increases. As a result, the life of the rotating scanning unit including the motor and the rotating mirror may be shortened.

[0012] An object of the present invention is to provide a small vehicle lamp capable of realizing high-precision light scanning in a rotating mirror.

[0013] Furthermore, an object of the present invention is to provide a vehicle lamp that achieves a longer life of a rotation scanning unit and a control method thereof.

[0014] The vehicle lamp of the present invention has:

[0015] light source;

[0016] a lighting control unit that controls emission timing of light emitted from the light source; and

[0017] a rotary scanning unit that repeatedly scans the light emitted from the light source while rotating,

[0018] The area of ​​interest is illuminated by scanning light.

[0019] In the vehicle lamp,

[0020] The rotating scanning unit is a structure that performs multiple repeated scans during one rotation.

[0021] The lighting control unit detects a rotation period of the rotary scanning unit, and controls the emission timing of the light source at timings obtained by equally dividing the detected rotation period.

[0022] In the present invention, it is preferred that the rotary scanning unit includes: a rotary mirror having a plurality of light reflecting sheets of the same shape arranged in a rotation direction; and a motor that rotationally drives the rotary mirror. The lighting control unit includes: a cycle detection unit that detects a rotation cycle of the motor; and a cycle division unit that detects a plurality of divided cycles obtained by equally dividing the detected rotation cycle. The lighting control unit controls the emission timing of the light source based on the detected rotation cycle and the divided cycle.

[0023] The vehicle lamp of the present invention comprises: a first lamp that performs illumination with a first light distribution; a second lamp that performs illumination with a second light distribution different from the first light distribution; and a lamp control unit that controls the rotation speed of a rotation scanning unit of the second lamp, wherein the second lamp has the rotation scanning unit that scans light emitted from a light source while rotating. The lamp control unit sets the rotation speed of the rotation scanning unit to a first rotation speed when the first lamp is on and the second lamp is on, and controls the rotation speed of the rotation scanning unit to another rotation speed that is lower than the first rotation speed when the first lamp is on and the second lamp is off.

[0024] The rotary scanning unit of the vehicle lamp of the present invention may include: a motor; and a rotary mirror which is rotationally driven by the motor and reflects the light emitted from the light source in different directions according to the change of the rotation position. In addition, the motor may include a bearing lubricated by a lubricant.

[0025] The lamp control unit of the present invention controls the rotation speed of the rotation scanning unit to a second rotation speed that is lower than the first rotation speed when the second lamp is turned off. In addition, when the second lamp is turned off, the lamp control unit may control the rotation speed of the rotation scanning unit to a third rotation speed that is lower than the first rotation speed and higher than the second rotation speed that is lower than the first rotation speed during a predetermined time from the time when the second lamp is turned off. Furthermore, when the second lamp is turned off, the lamp control unit may change the rotation speed of the rotation scanning unit from the first rotation speed to the second rotation speed that is lower than the first rotation speed continuously or in stages during a predetermined time from the time when the second lamp is turned off.

[0026] The vehicle lamp control method of the present invention comprises: a first lamp which performs illumination with a first light distribution; a second lamp which performs illumination with a second light distribution different from the first light distribution; and a lamp control unit which controls the lighting state of the light source of the second lamp, the second lamp having a rotating scanning unit which scans the light emitted from the light source, the vehicle lamp control method comprises: controlling the rotation speed of the rotating scanning unit to a first rotation speed when the first lamp is lit and the second lamp is lit, and controlling the rotation speed of the rotating scanning unit to a second rotation speed which is lower than the first rotation speed when the first lamp is lit and the second lamp is off, through the lamp control unit.

[0027] Effects of the Invention

[0028] The present invention is a lighting control unit that detects the rotation period of the rotating scanning unit, and controls the emission timing of the light source at a timing that divides the detected rotation period into equal parts, thereby obtaining a vehicle lamp that controls the emission timing of the light source and can perform ADB control with high precision.

[0029] Furthermore, the present invention controls the rotation speed of the rotating scanning unit when the light is off to be lower than the rotation speed when the light is on, thereby improving the lubricity of the bearings in the rotating scanning unit, reducing the total number of revolutions of the rotating scanning unit, and extending the life of the rotating scanning unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic horizontal cross-sectional view of a vehicle headlight to which the present invention is applied.

[0031] Figure 2 This is a schematic perspective view showing a portion of the rotary scanning unit cut away.

[0032] Figure 3 It is a cross-sectional view of the rotation scanning unit.

[0033] Figure 4 It is part of the structural block diagram of the lighting control device.

[0034] Figure 5 It is another part of the structural block diagram of the lighting control device.

[0035] Fig. 6A This is the light distribution characteristic diagram of low beam light distribution.

[0036] Figure 6B It is a light distribution characteristic diagram of high beam.

[0037] Figure 7 This is a light distribution characteristic diagram that explains ADB light distribution.

[0038] Figure 8 This is a diagram for explaining the correlation between the magnetization of a designed magnet and the scanning timing.

[0039] Fig. 9 This is a diagram for explaining the correlation between the magnetization of the magnet and the scanning timing, which is the first problem.

[0040] Fig.10 This is a diagram for explaining the correlation between the magnetization of the magnet and the scanning timing in the present invention.

[0041] Fig.11 This is a timing chart of motor rotation control for explaining Problem 2 of the prior art.

[0042] Fig.12 This is a timing chart of motor rotation control for explaining Problem 3 of the prior art.

[0043] Fig.13 This is a timing chart of lighting control according to Embodiment 1 of the present invention.

[0044] Fig.14 This is a timing chart of lighting control according to Embodiment 2 of the present invention.

[0045] Fig.15 This is a timing chart of a modified example of the lighting control of the second embodiment. DETAILED DESCRIPTION

[0046] Next, embodiments of the present invention will be described with reference to the drawings. Figure 1 1 is a schematic horizontal cross-sectional view of a headlamp HL (a vehicle lamp for illuminating a used area) of an automobile to which the present invention is applied. The headlamp HL has a lamp housing 1 composed of a lamp body 11 and a light-transmitting front cover 12. The headlamp HL also has a low beam lamp unit 2 and a high beam lamp unit 3 built into the lamp housing 1. In the following description, the front-back direction is a direction based on the front-back direction of the automobile and the lamp.

[0047] The low beam lamp unit 2 is the first lamp for performing the first light distribution in the present invention, and is configured as a projection type lamp unit. The low beam lamp unit 2 includes: a first white LED (light emitting diode) 21 as a light source for emitting white light; a reflector 22 that reflects the white light emitted from the first white LED 21 into a focused state; and a projection lens 23 that projects the white light focused by the reflector 22 to a forward area.

[0048] The high beam lamp unit 3 is a second lamp in the present invention that performs illumination of a second light distribution different from the first light distribution, and is configured as a lamp unit for ADB light distribution control of a light scanning method. The high beam lamp unit 3 includes: a second white LED 31 that emits white light; a rotating scanning unit 32 that reflects the white light emitted from the second white LED 31 and deflects the reflection direction of the white light in the horizontal direction; and a projection lens 33 that projects the reflected white light toward the front area of ​​the vehicle.

[0049] The lamp housing 1 contains an object detection device 4 (object detection unit) and a lighting control device 5 (light control unit). The object detection device 4 includes: a camera element 41 that captures the area in front of the car; and an image analysis unit 42 that analyzes the image captured by the camera element 41 to detect the object. If there is an object in the area in front of the car, the object is captured by the camera element 41 and detected by the image analysis unit 42, and position information including the position and direction of the object relative to the car is detected. The lighting control device 5 controls the light emission (emission timing) of the second white LED 31 based on the detected position information of the object. The object detection device 4 can be set outside the lamp housing 1. For example, the object detection device 4 can be set at a position facing the front window in the interior of the car, or at the front bumper or roof.

[0050] Figure 2 This is a schematic perspective view of a portion of the rotating scanning unit 32 that is cut away. The rotating scanning unit 32 includes: a brushless motor (hereinafter referred to as a motor) 6; and a rotating mirror 7, which is driven to rotate by the motor 6. The rotating mirror 7 is formed in a roughly circular plate shape as a whole by supporting two semicircular light reflecting sheets (hereinafter referred to as reflecting sheets) 71 and 72 on a boss 73. The boss 73 is integrally supported on one end of the rotating shaft 61 of the motor 6 in the rotation direction by a keyway or the like. The surface of each reflecting sheet 71 and 72, that is, the surface facing the oblique front of the car, is a light reflecting surface. The two reflecting sheets 71 and 72 have the same shape and are integrally formed together with the boss 73 by resin molding. A light reflecting film obtained by evaporation, plating, etc. of an aluminum film is formed on the surface of at least the two reflecting sheets 71 and 72.

[0051] The two reflection sheets 71 and 72 are point-symmetrically centered on the boss 73. The inclination angle of the surface as the light reflecting surface, that is, the inclination angle of the surface perpendicular to the axial direction of the rotating shaft 61 of the motor 6, changes continuously (gradually) along the rotation direction. As a result, when the rotating mirror 7 is rotationally driven by the motor 6, the horizontal angle of the reflection surface relative to the second white LED 31 changes continuously. The rotating mirror 7 is configured to scan the white light of the second white LED 31 in the horizontal direction by the angle change. In other words, the rotating mirror 7 reflects the light emitted from the second white LED 31 in different directions according to the rotation position change of the rotating mirror 7. In addition, a gap extending in the radial direction is provided between the circumferential direction of the two reflection sheets 71 and 72, and the gap is configured as a non-reflection area 74 where no light is reflected.

[0052] Figure 3 : is a cross-sectional view of the motor 6 and the rotating mirror 7. The motor 6 is assembled to a base 62 set in a circular shallow plate shape. The base 62 is fixed with a stator barrel 63 facing a hole 62a opened at the center. The rotating shaft 61 is rotatably supported by a pair of ball bearings 64 separated and arranged in the barrel axis direction inside the stator barrel 63. One end of the rotating shaft 61 extends to the surface side of the base 62, and the rotating mirror 7 is mounted on one end of the rotating shaft 61.

[0053] Coils 65 (four in this case) formed by winding a conductive wire around a core (iron core) are arranged at equal intervals in the circumferential direction on the outer peripheral surface of the stator cylinder 63. These coils 65 and the stator cylinder 63 constitute the stator of the motor 6.

[0054] A rotor yoke 66 is mounted on the other end of the rotating shaft 61. The rotor yoke 66 is configured as a short cylindrical container arranged at the outer circumference of the stator tube 63 and the coil 65. The rotor yoke 66 is made of a strong magnet and is integrally mounted on the other end of the rotating shaft 61 at the center of the circular bottom wall. A cylindrical magnet 67 is mounted on the inner surface of the circumferential wall of the rotor yoke 66. Figure 2 As shown, the magnet 67 is magnetized to form a plurality of pairs of magnetic poles in an area roughly divided into four equal parts in the circumferential direction, and the S poles and N poles are arranged alternately. In the circumferential direction, one of the plurality of pairs of magnetic poles is located at a position corresponding to one light reflecting sheet. The magnet 67 and the rotor yoke 66 together constitute the rotor of the motor 6.

[0055] A circuit board 8 is mounted on the back side of the base 62. Circuit components constituting the lighting control device 5 are mounted on the circuit board 8. The lighting control device 5 has a motor control unit 51 and a lighting control unit 52. The motor control unit 51 controls the rotation of the motor 6, and the lighting control unit 52 controls the lighting state of the first white LED 21 (low beam unit 2) and the second white LED 31 (high beam unit 3). In addition, a Hall element 81 for detecting the rotation state of the motor 6 is mounted on the circuit board 8 as one of the circuit components. A connector 82 for electrical connection with an external power source or the like is mounted on the circuit board 8.

[0056] At least one Hall element 81 is usually arranged in a part of the circumferential direction. The Hall element 81 detects the change of the S pole and the N pole of the magnet 67 by using the Hall effect, thereby detecting the rotation state of the rotor yoke 66, that is, the rotating shaft 61. And, based on this detection, the power supply to the coil 65 is controlled to control the rotation of the motor 6. The detailed description of the motor control by the Hall element 81 is omitted. In addition, when the motor control is to be controlled with high precision, two or three Hall elements 81 may be provided.

[0057] In the present invention, the lighting control unit 52 controls the lighting state of the second white LED 31 of the high beam lamp unit 3 , that is, light emission and light extinction (including dimming), based on the detection signal detected by the Hall element 81 .

[0058] Figure 4 It is a part of the structural block diagram of the lighting control device 5. As described in detail later, the lighting control unit 52 includes: a rotation position detection unit 521, which detects the rotation position of the motor 6 and the rotating mirror 7 based on the detection signal of the Hall element 81; a timing detection unit 522, which detects the light emission timing according to the detected rotation position; and a light emission control unit 523, which controls the light emission of the second white LED 31 based on the detected timing.

[0059] Figure 5 It is another part of the structural block diagram of the lighting control device (light control unit) 5. The lighting control unit 52 includes: a low beam control unit 526, which controls the light emission of the first white LED 21 of the low beam lamp unit 2 based on the on signal of the light switch LSW; and a high beam control unit 527, which controls the light emission of the second white LED 31 of the high beam lamp unit 3. When the ADB switch ASW is turned on and switched to the ADB light distribution control, the high beam control unit 527 can control the light emission of the second white LED 31 based on the detection signal detected by the Hall element 81.

[0060] The motor control unit 51 includes a rotation speed control unit 511 for controlling the rotation speed of the motor 6. The rotation speed control unit 511 controls the rotation speed of the motor 6 based on the lighting control state in the lighting control unit 52, that is, the light emission state of the first white LED 21 and the second white LED 31. Here, the rotation speed control unit 511 can control the motor 6 to a predetermined first rotation speed set in advance in order to rotate the rotating mirror 7 at a predetermined rotation speed when performing ADB light distribution control. In addition, it is also possible to control the motor 6 to a rotation speed lower than the first rotation speed. In addition, the motor control unit 51 includes a timer 512 for executing the embodiment of the present invention.

[0061] In the above headlamp HL, when the light switch LSW is turned on, if the low beam lamp unit 2 is turned on by the lighting control unit 52 (low beam control unit 526) of the lighting control device 5, Fig. 6A As shown in the light distribution characteristic diagram, the low beam distribution area PL (Lo distribution lighting) is illuminated. That is, when the first white LED 21 emits light, a cut-off line COL is provided that extends approximately along the horizontal line H in the front area of ​​the vehicle, and the low beam distribution area PL (upper left dashed line area) below the cut-off line COL is illuminated. The cut-off line COL has a height difference between the right side (oncoming vehicle line side) and the left side (own vehicle line side) of the vertical line V.

[0062] On the basis of the lighting of the low beam lamp unit 2, if the high beam lamp unit 3 is lit by the high beam control unit 527 of the lamp control unit 5, Figure 6B As shown in the light distribution characteristic diagram, the high beam light distribution area PH (Hi light distribution illumination) is illuminated on the basis of the low beam light distribution area PL. That is, if the second white LED 31 emits light, the light emitted from the LED 31 is projected onto the surfaces of the reflection sheets 71 and 72 of the rotating mirror 7, and is reflected on the surfaces of the reflection sheets 71 and 72. The reflected light beam enters the projection lens 33, and is projected toward the front of the headlight HL, that is, the front of the car, and illuminates the area in front of the car.

[0063] When the rotating mirror 7 is rotated by the motor 6 at the same time as the second white LED 31 emits light, the position in the circumferential direction at which the light from the second white LED 31 is incident on the surfaces of the reflective sheets 71 and 72 of the rotating mirror 7 changes in the circumferential direction. The inclination angle of the surfaces of the reflective sheets 71 and 72 changes in the circumferential direction, so that the incident angle of the incident light beam changes with the rotation of the rotating mirror 7, and the reflection angle of the reflected light also changes and scans in the horizontal direction. The white light (white light beam) L from the second white LED 31 is repeatedly scanned in the horizontal direction by the rotation of the rotating mirror 7. By this scanning, as shown in the figure, the high-beam distribution area PH in the area (upper right dotted line area) above the cut-off line COL of the low-beam distribution area PL is illuminated (Hi distribution illumination).

[0064] In the case of high-beam illumination (Hi-beam illumination), the image sensor 41 in the object detection device 4 captures the area in front of the vehicle (the surroundings of the vehicle), and the image analysis unit 42 detects the object based on the captured image. Figure 7 In the example shown, pedestrians M1, M2 and an oncoming vehicle CAR are detected. When these objects are detected, the lighting control unit 52 controls the timing and light intensity of the second white LED 31 based on the position (direction) of the object detected by the object detection device 4 and the rotation position of the rotating mirror 7 detected by the Hall element 81. Here, the lighting control unit 52 includes extinguishing or dimming the second white LED 31.

[0065] Therefore, if Figure 7 As shown, in the high-beam light distribution area PH, the light beam L of the second white LED 31 is not irradiated in the area where the objects M1, M2, and CAR exist, and the illumination by the high-beam lamp unit 3 is limited. Outside the area where the objects M1, M2, and CAR exist, the illumination of the required light intensity is performed by the light beam L of the second white LED 31. Therefore, the oncoming vehicle CAR and the pedestrians M1 and M2, which are the objects, are not dazzled, and the ADB light distribution control that improves the visual recognition of the area in front of the car is realized. Hereinafter, the Hi light distribution lighting that can perform the ADB light distribution control will be referred to as Hi light distribution lighting (ADB light distribution control).

[0066] In the high beam lamp unit 3, the lighting control unit 52 controls the light emission of the second white LED 31 based on the detection signal of the Hall element 81. For the light emission control of the second white LED 31, refer to Figure 8 For explanation. Figure 8 As shown in the upper part of the magnet 67, the magnet 67 is magnetized to have two N poles and S poles in the circumferential direction. If the motor 6 rotates one circle, the Hall element 81 outputs Figure 8The horizontal axis is the rotation angle (time), and the vertical axis is the output level. The rotation position detection unit 521 detects the first rotation position θ1 and the second rotation position θ2 where the signal switches from negative to positive. These rotation positions θ1 and θ2 correspond to the rotation positions of 0° and 180° during one rotation of the rotating mirror 7.

[0067] The timing detection unit 522 detects the first timing t1 and the second timing t2 which are delayed by the time Δt corresponding to the predetermined rotation angle Δθ from the rotation positions θ1 and θ2. The light control unit 523 starts the light emission of the second white LED 31 based on the first timing t1, and after continuing the light emission for the predetermined time ts, turns off the light or dims the light. Next, the light control unit 523 starts the light emission of the second white LED 31 again based on the second timing t2, and after continuing the light emission for the predetermined time ts, turns off the light or dims the light.

[0068] Therefore, if Figure 8 As shown in the lower part of the figure, in the rotating mirror 7 rotating in the counterclockwise direction, scanning is performed in the respective areas r1 and r2 in the circumferential direction of the two reflective sheets 71 and 72, that is, the areas with the same tilt angle. Therefore, the reflection direction of the light that is periodically and regularly changed and scanned by the two reflective sheets 71 and 72, that is, the illumination area is completely consistent, realizing high-precision illumination of the high-beam distribution area and ADB distribution control.

[0069] However, in the magnetization process of the magnet 67 when manufacturing the motor 6, it is difficult to accurately manufacture the four magnetic poles, and sometimes errors (fluctuations) occur in the length of each magnetic pole in the circumferential direction. Fig. 9 As shown in the upper part of , in magnet 67, even if four magnetic poles (two N poles and two S poles each) are magnetized based on the set first rotation position θ1, sometimes the circumferential length of one S pole is magnetized longer than the design value, and the boundary between the S pole and the next N pole, i.e., the second rotation position θ2, is offset in the clockwise direction compared to the design, as in the second rotation position θ2'.

[0070] Here, when the rotating mirror 7 is mounted on the motor 6, although detailed description is omitted, the non-reflection area 74 of the rotating mirror 7 is detected using a light reflecting mirror, and the rotation position of the detected non-reflection area 74 is set as the reference rotation position. In addition, one boundary between the N pole and the S pole in the magnet 67 of the motor 6 is set as the first rotation position, and the first rotation position is positioned relative to the reference rotation position, and the rotating mirror 7 is mounted on the motor 6 in this state. Therefore, the first rotation position θ1 can be accurately positioned relative to the non-reflection area 74 of the rotating mirror 7.

[0071] As described above, if the positional deviation occurs such that the second rotational position θ2 becomes the second rotational position θ2′, the Hall element 81 outputs the signal after the motor 6 rotates once. Fig. 9 The first rotational position θ1 detected by the rotational position detection unit 521 is the same, but the second rotational position θ2' is delayed on the time axis compared to the normal rotational position θ2.

[0072] The timing detection unit 522 detects the timing t1 and t2' which are delayed by a time Δt corresponding to a predetermined rotation angle Δθ from the rotation positions θ1 and θ2'. The light control unit 523 starts the light emission of the second white LED 31 based on the timing t1 and t2', and then turns off or dims the light after continuing to emit light for a predetermined time ts. Fig. 9 As shown in the lower part of the rotating mirror 7, the tilt angle of the circumferential area r1 in one reflective sheet 71 and the tilt angle of the circumferential area r2' in the other reflective sheet 72 are different from each other, and scanning is performed in these areas r1 and r2'. Therefore, the reflection direction of the light that is periodically and regularly changed and scanned by the two reflective sheets 71 and 72, that is, the projection direction, is different. Due to this difference, deviation occurs in the scanning, making it difficult to achieve high-precision lighting of the high-beam distribution area and ADB distribution control.

[0073] In the above case, the light reflected by the reflection sheet 72 becomes scanning light that moves in a more horizontal direction than the light reflected by the reflection sheet 71. Figure 7 As shown by the two-dot chain line, the scanning light sometimes irradiates the oncoming vehicle CAR and pedestrians M1 and M2 as the target, causing the target to be blinded. This is also the case when the second rotation position θ2' is earlier than the normal second rotation position θ2 on the time axis, and becomes the scanning light delayed in the horizontal direction.

[0074] In the present invention, if Figure 4 As shown, the timing detection unit 522 of the lighting control unit 52 includes a period detection unit 524 and a period division unit 525. The period detection unit 524 detects the time for the rotating mirror 7 to rotate one circle as a period 1T. The period division unit 525 detects a divided period 1 / 2T in which the detected period is divided into 1 / 2. Moreover, the timing detection unit 522 outputs the first timing and the second timing to the light emission control unit 523 based on the detected period and the divided period, and the light emission control unit 523 is configured to control the light emission of the second white LED 31 based on the first and second timings.

[0075] As described above, the timing detection unit 522 has a period detection unit 524 and a period division unit 525, thereby solving the problem of Fig. 9 The problem 1 shown. That is, Fig.10 The upper part, with Fig. 9 Similarly, if the circumferential length of one S pole of the magnet 67 is longer than the designed value, and the boundary between the S pole and the N pole, i.e., the second rotation position θ2', is offset in the clockwise direction compared to the designed value, then Fig.10 After the motor 6 rotates one circle, the Hall element 81 outputs Fig.10 The signal D' in the middle.

[0076] If the first rotation position θ1 based on the non-reflection area 74 of the rotating mirror 7 is detected in the timing detection unit 522, the period 1T from the first rotation position θ1 to the next first rotation position θ1 is detected based on the signal D' in the period detection unit 524. At this time, the second rotation position is not detected. Next, the period division unit 525 detects the divided period 1 / 2T that divides the detected period 1T into 1 / 2, and outputs the rotation position corresponding to the divided period as the second rotation position θ2. That is, the second rotation position θ2 is a position 180° in the circumferential direction of the rotating mirror 7 relative to the first rotation position θ1.

[0077] In the period detection unit 524, the motor 6 performs a constant speed rotation motion, so the period 1T can be easily and accurately detected based on the rotation speed of the motor 6. In addition, in the period division unit 525, the period 1T is halved, so that the second rotation position θ2 can be easily and accurately calculated.

[0078] The timing detection unit 522 detects the first timing t1 and the second timing t2 which are delayed by the time Δt corresponding to the predetermined rotation angle Δθ from the first and second rotation positions θ1 and θ2. The light emission control unit 523 starts the light emission of the second white LED 31 based on the first timing t1, and after continuing the light emission for the predetermined time ts, turns off the light or dims the light. Next, the light emission control unit 523 starts the light emission of the second white LED 31 based on the second timing t2, and after continuing the light emission for the predetermined time ts, turns off the light or dims the light.

[0079] Therefore, if Fig.10 As in the lower part, the magnet 67 is correctly magnetized with the magnetic poles Figure 8 Similarly, the two reflection plates 71 and 72 of the rotating mirror 7 are scanned in the areas r1 and r2 with the same inclination angle. In the rotating mirror 7, the reflection direction of the light alternately scanned by the two reflection plates 71 and 72, that is, the projection direction is completely consistent, so that the following is achieved: Figure 7 High-precision lighting of the high-beam distribution area and ADB distribution control as shown by the solid line.

[0080] If the lighting control device 5 detects the rotation cycle of the motor 6 driving the rotating mirror 7, the first and second timings are detected based on the rotation cycle, thereby controlling the light emission of the second white LED 31 of the high beam unit 3 and realizing ADB control with high accuracy. In addition, only small electronic components such as Hall elements can be used when detecting the rotation cycle, so that the high beam unit 3 and the headlight HL can be miniaturized.

[0081] In the above-described embodiment, the present invention is applied to the high beam unit 3 of the headlight, but a scanning type lamp may be configured by arranging a rotating mirror in the low beam unit 2. In the above case, the present invention can also be applied to the rotating mirror of the low beam unit 2.

[0082] In the embodiment, the structure in which the rotating mirror has two reflectors is described, but the rotating mirror may also have more than or equal to 3 reflectors. In the present invention, when the reflectors are composed of n (n is an integer greater than or equal to 2), the period is divided into n equal parts in the period dividing unit of the timing detection unit.

[0083] Regarding the motor, a configuration example in which the magnet has four magnetic poles in the circumferential direction is described, but the number of magnetic poles is not limited. In addition, regarding the lighting control device, a rotation position detection unit for detecting the rotation position of the motor may be a configuration using a position detector other than a Hall element.

[0084] The light control unit can not only control the light emission and extinction of the light source, but also control the light reduction of the light source. In addition, it can also be configured to control the emission state of light from the light source while continuing the light emission and moving the light shielding material (light shield) forward and backward relative to the light path of the light source. In particular, it is effective to control the emission of light through the light shield when the light source uses a light emitting body different from the semiconductor light emitting element.

[0085] In the embodiment, the object detection device is disposed in the lamp housing, but the present invention is not limited thereto and may be disposed in a vehicle body panel such as in the vehicle interior facing the front window or in the engine compartment, or even in the bumper.

[0086] In a headlamp that performs ADB light distribution control, when the high beam lamp unit 3 is turned on, the conventional technology of controlling the rotating mirror 7 to rotate synchronously therewith causes a second problem. That is, Fig.111 is a timing chart showing the correlation between the lighting control of the low beam unit 2 and the high beam unit 3 and the rotation speed of the rotating mirror 7 (motor 6). Hereinafter, the rotation of the rotating mirror 7 is assumed to be the rotation of the motor 6. The horizontal axis shows the change of time (t), and the low beam unit 2 is lit from t1 to t2 and from t3 to t4, and the high beam unit 3 is also lit from t4 to t5. t1 and t3 are the lighting times of the low beam unit 2, t4 is the lighting time of the high beam unit 3, and t5 is the lighting time of the high beam unit 3. In this lighting control, if the rotation of the motor 6 is started only at the same time as the light emission of the second white LED 31 of the high beam unit 3, the rotation speed is unstable during the rise time Δt3 until the motor 6 reaches the first rotation speed v1, and the light distribution characteristics of the Hi light distribution lighting (ADB light distribution control) are reduced.

[0087] In order to solve the problem 2, Patent Document 2 discloses a solution, but Problem 3 may arise in Patent Document 2. Fig.12 As shown, when the low beam unit 2 is turned on, the motor 6 is controlled to rotate at the first rotation speed v1 regardless of the turning on / off of the high beam unit 3. That is, it is self-evident that the motor 6 is controlled to rotate during t4 to t5 when the high beam unit 3 is turned on in Patent Document 2, but the motor 6 is also controlled to rotate during t1 to t2, t3 to t4, and t5 when only the low beam unit 2 is turned on.

[0088] According to Patent Document 2, when the high beam lamp unit 3 is turned on and Hi light distribution lighting (ADB light distribution control) is started, the motor 6 has already reached the predetermined first rotation speed v1. The flickering of lighting accompanying the change of the rotation speed of the motor 6 in the rise time Δt3 of the motor 6 is prevented. In addition, when the Hi light distribution lighting (ADB light distribution control) is set, the light switch LSW must be turned on in advance to turn on the low beam lamp unit 2, so the motor 6 reaches the first rotation speed v1 when the high beam lamp unit 3 is turned on.

[0089] In addition, according to Patent Document 2, the motor 6 also rotates during the Lo distribution lighting when the high beam lamp unit 3 is turned off, so that the viscosity of the lubricating oil of the bearing (ball bearing) 64 of the motor 6 is prevented from increasing when the motor 6 stops, thereby suppressing the shortening of the life of the bearing 64 due to the reduction of lubricity. However, when the Hi distribution lighting (ADB distribution control) stops, the motor 6 also rotates at the first rotation speed v1, so the total number of revolutions of the motor 6 increases, and the wear of the bearing 64 becomes a problem, resulting in the problem 3 that the life of the motor 6 is shortened.

[0090] In the present invention, the lamp control unit 5 is similar to the prior art. When the low beam lamp unit 2 is turned on by the lighting control unit 52, the motor 6 is rotated by the motor control unit 51 simultaneously with the turning on of the low beam lamp unit 2. In addition, when the high beam lamp unit 3 is turned on in addition to the turning on of the low beam lamp unit 2, the motor 6 rotates at the first rotation speed v1, and the Hi light distribution lighting (ADB light distribution control) is performed in the same manner.

[0091] On the other hand, when the low beam lamp unit 2 is on and the high beam lamp unit 3 is not on, that is, when only the low beam lamp unit 2 is on for Lo light distribution, the lamp control unit 5 controls the motor 6 to rotate at a speed lower than the first rotation speed v1. Next, an embodiment of the rotation control of the motor 6 will be described.

[0092] (Implementation Method 1)

[0093] Fig.13 It is a timing diagram showing the correlation between the lighting state of the low beam unit 2 and the high beam unit 3 and the rotation speed of the motor 6 in the first embodiment. The horizontal axis t1 to t5 is the time. The headlight HL is turned off during the period t0 to t1 and t2 to t3. That is, both the low beam unit 2 and the high beam unit 3 are turned off. During the period t1 to t2, t3 to t4, and t5, only the low beam unit 2 is turned on for Lo light distribution illumination, and during the period t4 to t5, the high beam unit 3 is also turned on to perform Hi light distribution illumination and ADB light distribution control.

[0094] During the period of t1 to t2 and t3 to t4 of the Lo light distribution lighting, the high beam lamp unit 3 is off, but the motor 6 rotates. The rotation speed of the motor 6 is controlled to be a second rotation speed v2 (other rotation speed) lower than the first rotation speed v1 when the Hi light distribution lighting (ADB light distribution control) is executed (v1>v2). Here, the second rotation speed v2 is set to a rotation speed of 50% of the first rotation speed v1.

[0095] In the Hi lighting and ADB lighting control from t4 to t5 when the high beam unit 3 is turned on based on the Lo lighting, the rotation speed of the motor 6 is increased from the second rotation speed v2 to the first rotation speed v1. As a result, light scanning is performed in the high beam unit 3 by the rotating mirror 7, and the high beam area PH is illuminated (ADB lighting control). At this time, the motor 6 is increased from the second rotation speed v2 of 50% of the first rotation speed v1 to the first rotation speed v1, so compared with the case where the motor 6 starts to rotate from a stopped state, the rise time Δt1 to reach the first rotation speed v1 becomes extremely short, and the influence of the flicker of the lighting accompanying the change of the rotation speed is almost not generated, thereby preventing the reduction of the lighting characteristics due to the sense of incongruity and discomfort to the driver.

[0096] Furthermore, the motor 6 is also continuously controlled to rotate during the Lo light distribution illumination, thereby suppressing the reduction in lubricity of the lubricating oil in the bearing 64. Therefore, even when the temperature of the headlamp HL rises due to the lighting of the low beam lamp unit 2, the reduction in lubricity of the lubricating oil is suppressed even when the temperature of the motor 6 rises.

[0097] Furthermore, even if the Hi light distribution lighting (ADB light distribution control) ends and becomes the Lo light distribution lighting, the motor 6 continues to rotate, so there is a concern about the influence of wear in the bearing 64 of the motor 6. However, the rotation speed of the motor 6 is the second rotation speed v2 which is 50% of the first rotation speed v1, so the increase in the total number of revolutions of the motor 6 relative to the rotation time is suppressed, and the life of the motor 6 can be extended.

[0098] Furthermore, when the headlights HL are turned off as in t2 to t3, the rotation of the motor 6 also stops. However, the temperature of the motor 6 hardly rises when the headlights HL are turned off. Therefore, even if the rotation of the motor 6 stops, the lubricity of the lubricating oil in the bearing 64 of the motor 6 is suppressed from decreasing.

[0099] (Implementation Method 2)

[0100] Fig.14 1 is a timing diagram showing the lighting of the low beam lamp unit 2 and the high beam lamp unit 3 and the rotation control of the motor 6 by the lamp control unit 5 in Embodiment 2. In Embodiment 2, similarly to Embodiment 1, the motor 6 rotates at the first rotation speed v1 in Hi light distribution lighting (ADB light distribution control), and rotates at the second rotation speed v2 which is lower than the first rotation speed v1 in Lo light distribution lighting.

[0101] On the other hand, in the second embodiment, when the Hi light distribution control (ADB light distribution control) is switched to the Lo light distribution lighting at t5, that is, when only the high beam lamp unit 3 is turned off among the low beam lamp unit 2 and the high beam lamp unit 3 that are turned on, during the prescribed switching time tx thereafter (predetermined time from the time when the high beam lamp unit 3 is turned off), as shown in FIG. Fig.14 As shown by the solid line in the middle, the rotation speed of the motor 6 is controlled to be a third rotation speed v3 (other rotation speed) which is higher than the second rotation speed v2 (v1>v3>v2). Here, the third rotation speed v3 is set to 70% of the first rotation speed v1. In addition, the conversion time tx is Figure 5 The timer 512 of the motor control unit 51 shown is set in advance.

[0102] In the second embodiment, similarly to the first embodiment, the motor 6 is still controlled to rotate when only the low beam lamp unit 2 is turned on, thereby suppressing the reduction of the lubricity of the lubricating oil. In addition, when the high beam lamp unit 3 is turned off, the motor 6 is still rotated at the second rotation speed v2 or the third rotation speed v3 which is lower than the first rotation speed v1, thereby suppressing the increase of the total number of revolutions of the motor 6 relative to the rotation time, and the life of the motor 6 can be extended.

[0103] In implementation mode 2, if Fig.14 As shown by the two-dot chain line, when the Hi light distribution lighting (ADB light distribution control) is switched to the Lo light distribution lighting at t5, the rotation speed of the motor 6 can be continuously reduced from the first rotation speed v1 toward the second rotation speed v2 during the switching time tx.

[0104] Alternatively, although not shown in the figure, the rotation speed of the motor 6 may be reduced stepwise from the first rotation speed v1 to the second rotation speed v2 instead of continuously reducing the rotation speed from the first rotation speed v1 to the second rotation speed v2 at the switching time tx.

[0105] In addition, in Embodiment 2, Fig.15 As shown, when switching from Hi light distribution lighting (ADB light distribution control) to Lo light distribution lighting at t5, the motor 6 rotates at the third rotation speed v3 during the switching time tx. Therefore, when switching to Hi light distribution lighting (ADB light distribution control) again at t6 during the switching time tx, the motor 6 increases from the third rotation speed v3 of 70% of the first rotation speed to the first rotation speed v1. As a result, compared with the case of rotating at the second rotation speed v2 as in the first embodiment, the rise time Δt2 until reaching the first rotation speed v1 is shortened, thereby improving the effect of preventing the flicker of the lighting accompanied by the change of the rotation speed.

[0106] In the second embodiment, after the predetermined switching time tx has passed, the rotation speed is reduced to the second rotation speed v2, which is the same as in the first embodiment. As described above, when the switching from the Lo light distribution to the Hi light distribution (ADB light distribution control) is not achieved even after the switching time tx has passed, the life of the bearing 64 can be given priority over the rise time in the motor 6.

[0107] In the first and second embodiments, the second rotational speed v2 is set to 50% of the first rotational speed v1, and in the second embodiment, the third rotational speed v3 is set to 70% of the first rotational speed v1, but these values ​​can be set appropriately. When the life of the bearing is given priority, the second rotational speed v2 is set to a lower speed than 50% of the first rotational speed v1, and when the starting characteristics of the motor are given priority, the second rotational speed v2 is set to a higher speed than 50% of the first rotational speed v1.

[0108] In the second embodiment, the light control unit 5 monitors the switching state of the Lo light distribution illumination and the Hi light distribution control (ADB light distribution control), and can perform control at the third rotation speed v3 when the frequency of switching within a preset time is high, and can perform control at the second rotation speed v2 when the frequency of switching is low. Alternatively, at least one of the second rotation speed v2 and the third rotation speed v3 can be appropriately changed and controlled according to the degree of frequency.

[0109] In the first and second embodiments, the vehicle lamps include a low beam unit and a high beam unit and are applied to headlamps that perform ADB light distribution control. However, the present invention can be applied to lamps that include a rotating scanning unit driven by a motor such as a rotating mirror.

[0110] The motor for rotationally driving the rotating mirror is not limited to the brushless motor described in the embodiment, and the present invention can be applied to any motor having a structure in which the bearing is lubricated by a lubricant. In addition, the bearing is not limited to the ball bearing described in the embodiment, and may be a sliding bearing.

[0111] This application claims the benefit of priority based on Japanese Application No. 2019-114172 filed on June 20, 2019 and Japanese Application No. 2019-114173 filed on June 20, 2019, and all the contents described in the aforementioned Japanese Applications are cited.

Claims

1. A vehicle lamp, comprising: a first lamp for performing illumination with a first light distribution; a second lamp for illuminating with a second light distribution different from the first light distribution; and a lamp control unit that controls the rotation speed of the rotation scanning unit of the second lamp, The second lamp has the rotating scanning unit that scans the light emitted from the light source while rotating. The lamp control unit sets the rotation speed of the rotation scanning unit when the first lamp is on and the second lamp is on to a first rotation speed, and controls the rotation speed of the rotation scanning unit when the first lamp is on and the second lamp is off to another rotation speed that is lower than the first rotation speed. When the second lamp is turned off, the lamp control unit controls the rotation speed of the rotation scanning unit to a third rotation speed for a predetermined time period from the time of the second lamp being turned off, the third rotation speed being lower than the first rotation speed and higher than the second rotation speed which is lower than the first rotation speed, Alternatively, when the second lamp is turned off, the lamp control unit changes the rotation speed of the rotation scanning unit from the first rotation speed to a second rotation speed that is lower than the first rotation speed continuously or stepwise during a predetermined time from the turning off of the second lamp.

2. The vehicle lamp according to claim 1, wherein: An object detection unit is provided, the object detection unit detects an object existing around the vehicle, The first lamp is a lamp for lighting a low beam. The second lamp is a lamp for performing ADB light distribution. The lamp control unit turns on the second lamp and controls the rotation scanning unit based on the detection by the object detection unit.

3. The vehicle lamp according to claim 1, wherein: The rotary scanning unit includes a motor and a rotary mirror that is rotationally driven by the motor and reflects the light emitted from the light source in different directions according to a change in a rotational position.

4. The vehicle lamp according to claim 3, wherein: The electric motor has bearings lubricated by a lubricant.

5. The vehicle lamp according to any one of claims 1 to 4, wherein: The lamp control unit controls the rotation speed of the rotation scanning unit to a second rotation speed that is lower than the first rotation speed when the second lamp is turned off.

6. A method for controlling a vehicle lamp, the vehicle lamp comprising: a first lamp that performs illumination with a first light distribution; a second lamp that performs illumination with a second light distribution different from the first light distribution; and a lamp control unit that controls a lighting state of a light source of the second lamp, The second lamp has a rotating scanning unit for scanning the light emitted from the light source. The vehicle lamp control method comprises: controlling the rotation speed of the rotation scanning unit to a first rotation speed when the first lamp is on and the second lamp is on, and controlling the rotation speed of the rotation scanning unit to a second rotation speed which is lower than the first rotation speed when the first lamp is on and the second lamp is off, through the lamp control unit. When the second lamp is turned off, the lamp control unit controls the rotation speed of the rotation scanning unit to a third rotation speed for a predetermined time period from the time of the second lamp being turned off, the third rotation speed being lower than the first rotation speed and higher than the second rotation speed which is lower than the first rotation speed, Alternatively, when the second lamp is turned off, the lamp control unit changes the rotation speed of the rotation scanning unit from the first rotation speed to a second rotation speed that is lower than the first rotation speed continuously or stepwise during a predetermined time from the turning off of the second lamp.

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