Control device, program, and vehicle lamp fitting

Abstract

A control device (60) controls an actuator (50) and includes a signal output unit (61) and a power supply control unit (62), wherein: in a calibration mode, if the absolute value of a difference between an emission direction angle and a target angle (TA) is less than a first threshold value (TH1) and equal to or greater than a reference threshold value (THB), the signal output unit (61) performs, one or more times, a signal output for outputting, to the power supply control unit (62) for a second time period (T2), a signal related to a specific direction from the emission direction angle toward the target angle (TA), and upon accepting input of the signal relating to the specific direction, the power supply control unit (62) controls the actuator (50) by causing a prescribed voltage to be applied to a motor (52) during the period in which the signal is being input; and in a leveling mode, if the absolute value of the difference between the emission direction angle and the target angle (TA) is less than the first threshold value (TH1) and the signal relating to the specific direction is being input, the power supply control unit (62) does not cause the voltage to be applied to the motor (52).

Description

Control device, program, and vehicle lighting fixture

[0001] The present invention relates to a control device, a program, and a vehicle lighting device.

[0002] 2. Description of the Related Art Vehicle lamps are known in which the orientation of a lamp unit can be changed by an actuator, and Patent Document 1 listed below discloses such a vehicle headlamp.

[0003] The vehicle headlamp disclosed in Patent Document 1 below includes a lamp unit, an actuator, and a control device that controls the actuator. The actuator is capable of changing the orientation of the lamp unit by using the torque of a motor to tilt the light emission direction of the lamp unit vertically. The control device controls the actuator based on the detection value of an inclination detection device that can detect the inclination angle of the vehicle. Therefore, with this vehicle headlamp, the vertical tilt of the light emission direction of the lamp unit can be changed in accordance with the inclination of the vehicle.

[0004] Patent No. 5947947

[0005] Generally, in a vehicle headlamp, the light emission direction relative to the vehicle is adjusted during calibration, such as when the headlamp is installed on the vehicle. Such adjustment of the light emission direction is performed, for example, by controlling an actuator based on measurement results from a measurement device that measures the emission direction of light emitted from a lamp unit. However, in order to prevent malfunction of the actuator, control of the actuator that finely changes the orientation of the lamp unit may be avoided. Therefore, if the deviation between the vertical angle of the emission direction and the target angle is small, the deviation may not be corrected. Furthermore, an actuator that can change the orientation of the lamp unit using the torque of a motor generally tends to have difficulty finely changing the orientation of the lamp unit. Therefore, if the deviation between the vertical angle of the emission direction and the target angle is small, the deviation may be difficult to correct. Therefore, there is a demand for improving the accuracy of adjustment of the emission direction of light emitted from the lamp unit.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a control device, a program, and a vehicle lamp that can improve the accuracy of adjusting the emission direction of light emitted from a lamp unit.

[0007] A first aspect of the present invention is a control device that controls an actuator that transmits torque of a motor to a lamp unit and can change the orientation of the lamp unit so that the light emission direction is tilted along a predetermined plane, and is switchable between a calibration mode and a mode other than the calibration mode, and includes a signal output unit and a power supply control unit, wherein in the calibration mode, the signal output unit is configured to output a signal that outputs a signal to the motor when the absolute value of the difference between the angle of the emission direction and a target angle is less than a first threshold that is the absolute value of the amount of change in the angle of the emission direction when a predetermined voltage is applied to the motor for a first period, or is equal to or greater than a reference threshold that is the absolute value of the amount of change in the angle of the emission direction when the predetermined voltage is applied to the motor for a reference period that is shorter than the first period. The present invention is characterized in that the power supply control unit outputs a signal relating to a specific direction from the angle of the emission direction toward the target angle to the power supply control unit for a second period that is equal to or less than twice the reference period, at least once, until the absolute value of the difference from the reference angle becomes less than the reference threshold value, and when the signal relating to the specific direction is input, the power supply control unit controls the actuator by applying the predetermined voltage to the motor for the period when the signal is input, so that the angle of the emission direction changes to the specific direction, and during at least a part of the period of the mode other than the calibration mode, when the absolute value of the difference between the angle of the emission direction and the target angle is less than the first threshold value and the signal relating to the specific direction is input, the power supply control unit does not apply voltage to the motor.

[0008] A second aspect of the present invention is a program executed by a control device that controls an actuator that transmits torque of a motor to a lamp unit and can change the orientation of the lamp unit so that the light emission direction is tilted along a predetermined plane, and that is switchable between a calibration mode and a mode other than the calibration mode, and that includes a signal output unit and a power supply control unit, wherein in the calibration mode, the signal output unit is configured to output a signal that, when an absolute value of a difference between the angle of the emission direction and a target angle is less than a first threshold value that is an absolute value of an amount of change in the angle of the emission direction when a predetermined voltage is applied to the motor for a first period, or is equal to or greater than a reference threshold value that is an absolute value of an amount of change in the angle of the emission direction when the predetermined voltage is applied to the motor for a reference period that is shorter than the first period, the absolute value of the difference between the angle of the emission direction and the target angle is equal to or greater than the reference threshold value. the step of outputting a signal relating to a specific direction from the angle of the emission direction toward the target angle to the power supply control unit for a second period that is equal to or less than twice the reference period one or more times until the absolute value of the difference between the angle of the emission direction and the target angle becomes less than a predetermined value; the step of controlling the actuator by applying the predetermined voltage to the motor for a period during which the signal is being input, when the signal relating to the specific direction is input to the power supply control unit, so that the angle of the emission direction changes to the specific direction; and the step of not applying voltage to the motor when the absolute value of the difference between the angle of the emission direction and the target angle is less than the first threshold value and a signal relating to the specific direction is input, during at least a part of the period of the mode other than the calibration mode.

[0009] A third aspect of the present invention provides a vehicle lamp comprising: an actuator that transmits torque of a motor to a lamp unit and changes the orientation of the lamp unit so that the light emission direction is tilted along a predetermined plane; and a control device that controls the actuator and is switchable between a calibration mode and a mode other than the calibration mode, the control device including a signal output unit and a power supply control unit, wherein in the calibration mode, the signal output unit outputs a signal indicating that the lamp unit is in a calibration state when an absolute value of a difference between an angle of the emission direction and a target angle is less than a first threshold value that is an absolute value of an amount of change in the angle of the emission direction when a predetermined voltage is applied to the motor for a first period, or is equal to or greater than a reference threshold value that is an absolute value of an amount of change in the angle of the emission direction when the predetermined voltage is applied to the motor for a reference period that is shorter than the first period. The present invention is characterized in that the power supply control unit outputs a signal relating to a specific direction from the angle of the emission direction toward the target angle to the power supply control unit for a second period that is equal to or less than twice the reference period, at least once, until the absolute value of the difference between the angle of the emission direction and the target angle becomes less than the reference threshold value, and when the signal relating to the specific direction is input, the power supply control unit controls the actuator by applying the predetermined voltage to the motor for the period when the signal is input, so that the angle of the emission direction changes to the specific direction, and during at least a portion of the period of the mode other than the calibration mode, when the absolute value of the difference between the angle of the emission direction and the target angle is less than the first threshold value and the signal relating to the specific direction is input, the power supply control unit does not apply voltage to the motor.

[0010] In the control device, program, and vehicular lamp according to the first to third aspects, during at least a portion of a mode other than the calibration mode, if the absolute value of the difference between the emission direction angle and the target angle is less than the first threshold, the orientation of the actuator is not changed. This can prevent malfunction of the actuator. However, in the calibration mode, if the absolute value of the difference between the emission direction angle and the target angle is less than the first threshold and equal to or greater than the reference threshold, the emission direction angle may be changed one or more times until the absolute value of the difference between the emission direction angle and the target angle becomes less than the reference threshold. Therefore, in the calibration mode, the emission direction angle may be brought closer to the target angle even if the absolute value of the difference between the emission direction angle and the target angle is less than the first threshold and equal to or greater than the reference threshold. Therefore, the control device, program, and vehicular lamp according to the first to third aspects can improve the accuracy of adjusting the emission direction of light emitted from the lamp unit, even in such a case.

[0011] The signal related to the specific direction may be a signal indicating a specific angle where the absolute value of the difference between the target angle on the angle side of the emission direction and the target angle on the opposite side of the emission direction from the target angle is equal to or greater than the first threshold. Alternatively, the signal related to the specific direction may be a signal indicating a value obtained by subtracting the angle of the emission direction from a specific angle where the absolute value of the difference between the target angle on the angle side of the emission direction and the target angle on the opposite side of the emission direction from the target angle is equal to or greater than the first threshold.

[0012] During the entire period of the modes other than the calibration mode, the power supply control unit may not apply voltage to the motor if the absolute value of the difference between the angle of the emission direction and the target angle is less than the first threshold value and a signal related to the specific direction is input.

[0013] In at least one of the calibration mode and the mode other than the calibration mode, the power supply control unit may not apply voltage to the motor if the absolute value of the difference between the target angle and one of the two ends of the angular range of the emission direction that can be changed by the actuator is equal to or less than a second threshold that is equal to or greater than the first threshold.

[0014] With this configuration, when the target angle is close to one of the two ends of the angular range of the emission direction that can be changed by the actuator, the orientation of the actuator can be prevented from changing, which can, for example, prevent malfunctions in the actuator.

[0015] As described above, according to the first to third aspects of the present invention, it is possible to provide a control device, a program, and a vehicle lamp that can improve the accuracy of adjusting the emission direction of light emitted from a lamp unit.

[0016] A fourth aspect of the present invention is a control device for an actuator that can change the orientation of a lamp unit by transmitting the torque of a motor to the lamp unit so that the light emission direction is tilted along a predetermined plane, and is characterized in that, when the absolute value of the difference between the angle of the emission direction and a target angle is equal to or greater than a first threshold value that is the absolute value of the amount of change in the angle of the emission direction when a first voltage is applied to the motor for a period of a time constant of the motor, a first control is performed to control the actuator by applying the first voltage to the motor for a first period of time equal to or greater than the time constant so that the angle of the emission direction approaches the target angle, and when the absolute value of the difference between the angle of the emission direction and the target angle is equal to or greater than a reference threshold value that is the absolute value of the amount of change in the angle of the emission direction when a second voltage is applied to the motor for a reference period shorter than the time constant but less than the first threshold value, a second control is performed to control the actuator by applying the second voltage to the motor for a second period of time that is equal to or less than twice the reference period one or more times until the absolute value of the difference between the angle of the emission direction and the target angle becomes less than the reference threshold value.

[0017] A fifth aspect of the present invention is a program executed by a control device of an actuator that can change the orientation of a lamp unit by transmitting torque of a motor to the lamp unit so that the light emission direction is tilted along a predetermined plane, the program including the step of causing the control device to apply the first voltage to the motor for a first period equal to or greater than the time constant so that the angle of the light emission direction approaches the target angle when an absolute value of a difference between the angle of the light emission direction and a target angle is equal to or greater than a first threshold value that is an absolute value of an amount of change in the angle of the light emission direction when a first voltage is applied to the motor for a period equal to a time constant of the motor. a step of performing a first control for controlling the actuator, and when the absolute value of the difference between the angle of the emission direction and the target angle is equal to or greater than a reference threshold which is the absolute value of the amount of change in the angle of the emission direction when a second voltage is applied to the motor for a reference period shorter than the time constant and is less than the first threshold, performing a second control for controlling the actuator by applying the second voltage to the motor for a second period which is equal to or less than twice the reference period one or more times until the absolute value of the difference between the angle of the emission direction and the target angle becomes less than the reference threshold.

[0018] A sixth aspect of the present invention provides a vehicle lamp comprising: a lamp unit; an actuator that can change the orientation of the lamp unit by transmitting torque of a motor to the lamp unit so that the light emission direction is tilted along a predetermined plane; and a control device that controls the actuator, wherein the control device is configured to apply the first voltage to the motor for a period of time constant of the motor when an absolute value of a difference between an angle of the emission direction and a target angle is equal to or greater than a first threshold that is an absolute value of an amount of change in the angle of the emission direction when a first voltage is applied to the motor for a period of time constant of the motor so that the angle of the emission direction approaches the target angle. a first control is performed to control the actuator by applying a second voltage for a first period equal to or greater than a constant; and when the absolute value of the difference between the angle of the emission direction and the target angle is equal to or greater than a reference threshold which is the absolute value of the amount of change in the angle of the emission direction when a second voltage is applied to the motor for a reference period shorter than the time constant and is less than the first threshold, a second control is performed to control the actuator by applying the second voltage to the motor one or more times for a second period which is equal to or less than twice the reference period until the absolute value of the difference between the angle of the emission direction and the target angle becomes less than the reference threshold.

[0019] In the control device, program, and vehicular lamp according to the fourth to sixth aspects, when the absolute value of the difference between the angle of the light emission direction and the target angle is equal to or greater than the reference threshold and less than the first threshold, a second voltage is applied to the motor for a second period at least once until the absolute value becomes less than the reference threshold. The reference threshold is the absolute value of the amount of change in the angle of the light emission direction when the second voltage is applied to the motor for a reference period shorter than the time constant, and the second period is equal to or less than twice the reference period. Therefore, with the control device, program, and vehicular lamp described above, even when the absolute value of the difference between the angle of the light emission direction and the target angle is equal to or greater than the reference threshold and less than the first threshold, making it difficult to correct the deviation between the angle of the light emission direction and the target angle, the angle of the light emission direction can be brought closer to the target angle. This improves the accuracy of adjusting the light emission direction of the lamp unit.

[0020] The second period may be equal to or less than the reference period.

[0021] With this configuration, the amount of change in angle due to one voltage application is small, making it easier to bring the angle of the light emission direction closer to the target angle.

[0022] The control device may perform the voltage application a plurality of times in the second control.

[0023] In this case, the period between voltage applications may be longer than the second period, or alternatively, the period between voltage applications may be shorter than the second period.

[0024] The former configuration can make it easier to measure the light emission direction during voltage application in the second control, while the latter configuration can prevent the time required to adjust the light emission direction from becoming long.

[0025] The second period in the voltage application performed later may be shorter, and the second voltage in the voltage application performed later may be smaller.

[0026] According to the former and latter configurations, the amount of change in the orientation of the lamp unit due to voltage application can be made smaller the later the voltage application is performed, so that the amount of change in the orientation of the lamp unit can be made smaller as the angle of the light emission direction approaches the target angle, making it easier to bring the angle of the light emission direction closer to the target angle.

[0027] The above-mentioned control device performs the second control when the absolute value of the difference between the angle of the emission direction and the target angle after the first control is equal to or greater than the reference threshold value and less than the first threshold value, and when the voltage application is performed multiple times in the second control, the period from the end of the first control to the start of the second control may be longer than the period between the voltage applications.

[0028] Since the period during which the motor rotates during the first control is longer than when the voltage is applied only once, the motor tends to continue rotating due to inertial force immediately after the end of the first control. With the above configuration, the second control can be started while the motor is stopped, thereby preventing a decrease in the accuracy of the adjustment of the light emission direction.

[0029] The second voltage may be less than the first voltage.

[0030] With this configuration, the amount of change in the orientation of the lighting unit due to voltage application can be reduced, making it easier to bring the angle of the light emission direction closer to the target angle.

[0031] When the first voltage is applied to the motor, the increase in rotational speed of the motor per unit time may gradually increase and then gradually decrease to zero, and the second period may be longer than the period from when the first voltage is applied to the motor to when the increase in rotational speed begins to decrease.

[0032] With this configuration, it is possible to prevent the orientation of the lamp unit from becoming unchangeable due to the application of voltage.

[0033] The control device may receive a signal relating to the angle of the emission direction from a measuring device that receives light emitted from the lighting unit and measures the emission direction.

[0034] As described above, according to the fourth to sixth aspects of the present invention, it is possible to provide a control device, a program, and a vehicle lamp that can improve the accuracy of adjusting the emission direction of light emitted from a lamp unit.

[0035] FIG. 1 is a schematic diagram showing an adjustment system for adjusting the emission direction of light emitted from a vehicle lamp according to a first embodiment. FIG. 2 is a schematic diagram showing a vehicle headlamp according to the first embodiment. FIG. 3 is a diagram showing a light distribution pattern of a low beam in the first embodiment. FIG. 4 is a flowchart showing an example of the operation of the control device in a calibration mode in the first embodiment. FIG. 5 is a diagram for explaining a target angle and a first threshold in the first embodiment. FIG. 6 is a timing chart showing an example of the operation of the actuator when a first control is performed. FIG. 7 is a diagram showing the change over time in the number of times the motor is rotated when a predetermined voltage is applied to the motor. FIG. 8 is a timing chart showing an example of the operation of the actuator when a second control is performed. FIG. 9 is a flowchart showing an example of the operation of the control device in a leveling mode in the first embodiment. FIG. 10 is a timing chart showing an example of the operation of the actuator when the second control in Modification 1 is performed. FIG. 11 is a schematic diagram showing an adjustment system for adjusting the emission direction of light emitted from a vehicle lamp according to a third embodiment. Fig. 12 is a diagram schematically showing a vehicle headlamp according to a third embodiment. Fig. 13 is a diagram for explaining a target angle and a first threshold value in the third embodiment. Fig. 14 is a diagram for explaining an electrical time constant of a motor. Fig. 15 is a timing chart schematically showing an example of the operation of the actuator when the second control is performed after the first control in the third embodiment. Fig. 16 is a timing chart schematically showing an example of the operation of the actuator when the second control is performed after the first control in Modification 2. Fig. 17 is a timing chart schematically showing an example of the operation of the actuator when the second control is performed after the first control in Modification 3.

[0036] Preferred embodiments of a control device, a program, and a vehicle lamp according to the present invention will be described in detail below with reference to the drawings. The embodiments exemplified below are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved from the embodiments exemplified below within the scope of the claims. Furthermore, the present invention may also be implemented by appropriately combining the components in the embodiments exemplified below. Note that in the drawings referred to below, the dimensions of each component may be changed to facilitate understanding. Furthermore, in the drawings, for ease of viewing, similar components may be assigned reference symbols only in some cases, and some reference symbols may be omitted.

[0037] First Embodiment A first embodiment will be described as first to third aspects of the present invention. FIG. 1 is a schematic diagram showing an adjustment system for adjusting the emission direction of light emitted from a vehicle lamp according to this embodiment. As shown in FIG. 1 , the adjustment system SY of this embodiment includes a vehicle 100 equipped with a vehicle headlamp 1 as a vehicle lamp, and a measurement device 110 for measuring the emission direction of light emitted from the vehicle headlamp 1. In FIG. 1 , the X-axis direction indicates the front of the vehicle 100, the Z-axis direction indicates the upward direction, and the Y-axis direction perpendicular to the paper surface and pointing toward the rear indicates the rightward direction of the vehicle 100. In this embodiment, the vehicle 100 is placed on a generally horizontal floor FL, and the measurement device 110 is placed on the floor FL in front of the vehicle 100 so as to directly face the vehicle headlamp 1 at a predetermined distance. In addition, "approximately horizontal" includes, for example, a state in which the object is horizontal, as well as a state in which the object is tilted from the horizontal to such an extent that the effect on the calibration of the vehicle headlamp 1 described later can be ignored, and an example of this state in which the object is tilted from the horizontal by a reference threshold value described later can be mentioned.

[0038] First, a description will be given of the vehicle headlamp 1. The vehicle headlamp 1 according to this embodiment mainly comprises a lamp unit 10, a control device 60, a memory 70, a first power supply circuit 81, and a second power supply circuit 82.

[0039] 2 is a diagram schematically illustrating the vehicle headlamp 1 according to this embodiment. As shown in FIG. 2, the lamp section 10 according to this embodiment mainly includes a housing 20, a lamp unit 30, a support member 40, and an actuator 50.

[0040] The housing 20 has a lamp housing 21 and a front cover 22. The front of the lamp housing 21 is open, and the front cover 22 is fixed to the lamp housing 21 so as to close the opening. The space formed by the lamp housing 21 and the front cover 22 is an accommodation space, and the lamp unit 30, the support member 40, and the actuator 50 are accommodated in this accommodation space. The front cover 22 transmits light emitted from the lamp unit 30.

[0041] The lamp unit 30 of this embodiment mainly comprises a main body 31 equipped with a light source (not shown), an upper connection part 32, and a lower connection part 35. Note that the internal structure of the main body 31 is not shown in Fig. 2 .

[0042] In this embodiment, the main body 31 emits light emitted from the light source forward so as to form a low beam light distribution. The low beam emitted from the main body 31 is irradiated forward of the vehicle 100 through the front cover 22. The main body 31 may include a reflector, a projection lens, or the like so that the light from the light source forms a low beam light distribution. An example of the light source is an LED (Light Emitting Diode). The light emitted by the main body 31 is not limited and may be, for example, a high beam, and the main body 31 may be capable of changing the light distribution pattern of the emitted light.

[0043] The upper connection portion 32 of this embodiment includes a base portion 33 extending upward from the main body portion 31 and a connection portion 34 fixed to the rear side of the base portion 33, and the connection portion 34 is connected to the support member 40. The support member 40 of this embodiment is a rod-shaped member extending in the front-to-rear direction and has a generally spherical pivot portion 41 at its front end. The rear end of the support member 40 is fixed to the lamp housing 21. The connection portion 34 has a recess into which the pivot portion 41 fits, and the upper connection portion 32 is connected to the support member 40 by fitting the pivot portion 41 into the recess. The lamp unit 30, with the upper connection portion 32 connected to the support member 40 in this manner, can swing up and down and left and right within a predetermined range relative to the support member 40, with the pivot portion 41 as a fulcrum.

[0044] The lower connecting portion 35 of this embodiment includes a base portion 36 extending downward from the main body portion 31 and a connecting portion 37 fixed to the rear side of the base portion 36, and is connected to a shaft 53 of an actuator 50 (described later). The lamp unit 30 is supported by the support member 40 and the shaft 53.

[0045] The actuator 50 of this embodiment mainly comprises a case 51, a motor 52, a shaft 53, and a position sensor 57.

[0046] In this embodiment, the case 51 is a box-shaped member having an internal storage space, and is fixed to the lamp housing 21. The motor 52 is a DC motor, and is housed in the storage space of the case 51. The type of the motor 52 is not limited.

[0047] In this embodiment, the shaft 53 is a rod-shaped member extending in the front-rear direction. The shaft 53 has a generally spherical pivot portion 54 at its front end, and a rack 55 behind the pivot portion 54. A hole through which the shaft 53 is inserted is formed in the front portion of the case 51, and the portion of the shaft 53 including the pivot portion 54 is located forward of the case 51, while the portion of the shaft 53 including the rack 55 is located within the accommodation space of the case 51. The shaft 53 is supported by a support mechanism (not shown) so as to be movable along the front-rear direction, which is the direction in which the shaft 53 extends.

[0048] The connection portion 37 of the lower connection portion 35 described above has a recess into which the pivot portion 54 fits, and the pivot portion 54 fits into this recess, thereby connecting the lower connection portion 35 to the shaft 53. The lighting unit 30, with the lower connection portion 35 connected to the shaft 53 in this way, can swing up and down and left and right within a predetermined range relative to the shaft 53, with the pivot portion 54 as a fulcrum.

[0049] The rack 55 is a gear provided on the outer circumferential surface of the shaft 53 along the longitudinal direction of the shaft 53, and meshes with a pinion gear 56 fixed to the output shaft 52a of the motor 52. When the pinion gear 56 rotates due to the torque of the motor 52, the shaft 53 moves in the front-to-rear direction, and when the rotation direction of the motor 52 is reversed, the movement direction of the shaft 53 is reversed.

[0050] The position sensor 57 detects the position of the shaft 53 in the front-rear direction. The position sensor 57 is electrically connected to the control device 60 and outputs a signal related to the detected position to a power supply control unit of the control device 60, which will be described later. An example of the position sensor 57 is a potentiometer. Note that the position sensor 57 only needs to be able to detect the position of the shaft 53 in the front-rear direction. For example, the position sensor 57 may be a rotation angle sensor that detects the rotation angle of the output shaft of the motor 52. In this case, the position of the shaft 53 in the front-rear direction can be detected from the rotation angle.

[0051] Although not illustrated, as the shaft 53 moves forward, the torque of the motor 52 is transmitted to the lamp unit 30, and the lamp unit 30 tilts so as to face upward, with the pivot portion 41 of the support member 40 as a fulcrum. The light emission direction of the main body 31 of the lamp unit 30 is then changed to be upward from before the movement. As the shaft 53 moves rearward, the torque of the motor 52 is transmitted to the lamp unit 30, and the lamp unit 30 tilts so as to face downward, with the pivot portion 41 as a fulcrum, and the light emission direction of the main body 31 is then changed to be downward from before the movement.

[0052] In other words, the pinion gear 56 and the shaft 53 are torque transmission members that transmit the torque of the motor 52 to the lamp unit 30, and the actuator 50 transmits the torque of the motor 52 to the lamp unit 30 and can change the orientation of the lamp unit 30 so that the light emission direction is tilted along a plane that is approximately parallel to a vertical plane extending in the front-to-rear direction. Note that "approximately parallel to the vertical plane" includes, for example, a state parallel to the vertical plane as well as a state tilted from the vertical plane to an extent that the influence of the calibration of the vehicle headlamp 1, which will be described later, is negligible. An example of this tilted state from the vertical plane is a state tilted at a predetermined angle from the vertical plane, which will be described later. Furthermore, the angle of the light emission direction tilts along the above plane depending on the position of the shaft 53 in the front-to-rear direction. In this embodiment, information related to the relationship between the position of the shaft 53 in the front-to-rear direction and the angle of the light emission direction is stored in the memory 70.

[0053] In addition, the center of gravity 30G of the lighting unit 30 in this embodiment is located forward of the pivot portion 41 and the pivot portion 54, and the weight of the lighting unit 30 generates a torque in the lighting unit 30 that changes the direction of light emission downward.

[0054] The control device 60 includes a signal output unit 61 and a power supply control unit 62 and is switchable between a calibration mode and a mode other than the calibration mode. The signal output unit 61 and the power supply control unit 62 are configured, for example, by an integrated circuit such as a microcontroller, an integrated circuit (IC), a large-scale integrated circuit (LSI), or an application-specific integrated circuit (ASIC), or a numerical control (NC) device. The signal output unit 61 and the power supply control unit 62 may or may not use a machine learning device. In this embodiment, the signal output unit 61 is electrically connected to the power supply control unit 62, a memory 70, a first power supply circuit 81, a transceiver unit 120 and an inclination sensor 130 provided in the vehicle 100 (described later). The power supply control unit 62 is electrically connected to the memory 70, the second power supply circuit 82, and a position sensor 57, and receives a signal output from the position sensor 57 indicating the longitudinal position of the shaft 53.

[0055] The memory 70 is configured to store information and to be able to read the stored information. The memory 70 is, for example, a non-transitory recording medium, and is preferably a semiconductor recording medium such as a random access memory (RAM) or a read-only memory (ROM), but may also include any type of recording medium, such as an optical recording medium or a magnetic recording medium. Note that "non-transitory" recording medium includes all computer-readable recording media except for transient, propagating signals, and does not exclude volatile recording media. Note that the memory 70 may be composed of a first memory connected to the signal output unit 61 and a second memory connected to the power supply control unit 62. The memory 70 stores programs for controlling the lamp unit 30 and the actuator 50 and information necessary for such control. The signal output unit 61 and the power supply control unit 62 read the programs and information stored in the memory 70. The memory 70 also stores information in response to instructions from the signal output unit 61 and the power supply control unit 62.

[0056] The signal output unit 61 of this embodiment reads out a program for controlling the lighting unit 30 from the memory 70, outputs a signal to the first power supply circuit 81, and controls the first power supply circuit 81, thereby controlling the lighting unit 30.

[0057] The first power supply circuit 81 includes a driver, and when a control signal is input from the signal output unit 61, the driver adjusts the power supplied from a power supply (not shown) to the light source in the main body 31 of the lamp unit 30. When power is supplied to the light source, light is emitted from the light source, and a low beam is emitted from the lamp unit 30.

[0058] Furthermore, the signal output unit 61 and the power supply control unit 62 of this embodiment read out a program for controlling the actuator 50 from the memory 70, and the signal output unit 61 outputs a signal to the power supply control unit 62. The power supply control unit 62 outputs a signal to the second power supply circuit 82 in response to the signal from the signal output unit 61, and controls the second power supply circuit 82, thereby controlling the actuator 50.

[0059] The second power supply circuit 82 includes a driver, and when a control signal is input from the power supply control unit 62, the driver adjusts the voltage applied to the motor 52 of the actuator 50 from a power supply (not shown), and the output shaft 52a of the motor 52 rotates in accordance with the applied voltage. The shaft 53 then moves forward and backward, and the torque of the motor 52 is transmitted to the lamp unit 30, changing the orientation of the lamp unit 30 so that the light emission direction is tilted upward and downward.

[0060] Furthermore, the signal output unit 61 of this embodiment outputs a control signal to the transceiver unit 120 provided in the vehicle 100 to instruct the measuring device 110 to perform measurement.

[0061] In the present embodiment, the signal output unit 61, the power supply control unit 62, the memory 70, the first power supply circuit 81, and the second power supply circuit 82 are disposed outside the housing 20. However, at least one of these may be housed in the housing space of the housing 20, and at least one of the power supply control unit 62 and the second power supply circuit 82 may be housed in the housing space of the case 51 of the actuator 50. Furthermore, the signal output unit 61 may include at least one of the power supply control unit 62, the first power supply circuit 81, and the second power supply circuit 82, and may be included in a vehicle control device that controls the engine of the vehicle 100, etc. Furthermore, the power supply control unit 62 may include the second power supply circuit 82. Furthermore, at least two of the signal output unit 61, the power supply control unit 62, the memory 70, the first power supply circuit 81, and the second power supply circuit 82 may be provided in an integrated package.

[0062] The transceiver 120 provided in the vehicle 100 is configured to transmit signals to and receive signals from the outside. An example of the transceiver 120 is an antenna. In this embodiment, the transceiver 120 transmits signals input from the control device 60 to an external device as electromagnetic waves, and receives signals transmitted from an external device as electromagnetic waves and outputs the signals to the control device 60.

[0063] The tilt sensor 130 provided in the vehicle 100 detects the tilt angle in the longitudinal direction of the vehicle 100. The tilt sensor 130 is electrically connected to the signal output unit 61, and outputs a signal related to the detected tilt angle to the signal output unit 61. An example of the tilt sensor 130 is a gyro sensor.

[0064] 1 , the measuring device 110 will be described. The measuring device 110 according to this embodiment mainly includes a control device 111, a memory 112, a light receiving unit 113, a calculation unit 114, and a transmission / reception unit 115.

[0065] The control device 111 has a configuration similar to that of, for example, the signal output unit 61, and controls several components of the measurement device 110. The control device 111 is electrically connected to a memory 112, a light receiving unit 113, a calculation unit 114, and a transmission / reception unit 115.

[0066] The memory 112 has a configuration similar to that of the memory 70, for example. The memory 112 stores programs for controlling several components of the measuring device 110 and information necessary for the control. The control device 111 reads out the programs and information stored in the memory 112. The memory 112 also stores information in response to instructions from the control device 111.

[0067] The light receiving unit 113 of this embodiment has a light receiving surface 113s that receives light, and generates image information indicating an image of the light irradiated onto the light receiving surface 113s. The generated image information is output to the calculation unit 114 via the control device 111. The light receiving unit 113 may be configured, for example, with semiconductor light receiving elements arranged in a matrix. The measurement device 110 is placed on the floor FL so that the light receiving surface 113s faces the vehicle headlamp 1 at a predetermined distance. When a low beam is emitted from the vehicle headlamp 1, the low beam is irradiated onto the light receiving surface 113s, and image information indicating the low beam light distribution pattern, which is an image of the low beam, is output to the calculation unit 114 via the control device 111.

[0068] 3 is a diagram showing a low beam light distribution pattern according to this embodiment, specifically, a low beam light distribution pattern formed on the light receiving surface 113s when the low beam is irradiated onto the light receiving surface 113s. The low beam light distribution pattern PL according to this embodiment is suitable for countries and regions where vehicles drive on the left side of the road. The cutoff line CL, which is the upper edge of the low beam light distribution pattern PL, includes a first line CL1, a second line CL2, and a third line CL3. The first line CL1 extends generally horizontally, the second line CL2 extends leftward and upward from the left end of the first line CL1, and the third line CL3 extends generally horizontally from the left end of the second line CL2 to the left. The junction of the first line CL1 and the second line CL2 is an elbow point EP, and a hot zone (not shown), which is the area where the light intensity is highest, is located near the elbow point EP.

[0069] The calculation unit 114 in this embodiment has a configuration similar to that of the signal output unit 61, for example. The calculation unit 114 calculates the emission direction of the low beam with respect to the vehicle 100 based on information about the input image and information previously stored in the memory 112. Examples of the information stored in the memory 112 include the distance between the vehicle 100 and the measurement device 110 and the height from the floor FL to the vehicle headlamp 1. In this embodiment, the calculation unit 114 extracts a position representing the elbow point EP in the image and calculates the angle of the emission direction of the low beam in the vertical direction from the extracted position. Information about the calculated angle is output to the transmission / reception unit 115 via the control device 111. In this embodiment, the angle of the emission direction is defined as zero degrees in a direction parallel to the horizontal direction, a positive angle in an angle formed between a direction above the horizontal direction and the horizontal direction, and a negative angle in an angle formed between a direction below the horizontal direction and the horizontal direction. In this embodiment, the low beam is emitted in a direction from the lamp unit 30 toward the elbow point EP. When the orientation of the lamp unit 30 is changed by the actuator 50, the emission direction is tilted along a plane VP that is generally parallel to a vertical plane extending in the front-to-rear direction and passes through the elbow point EP.

[0070] The calculation unit 114 is only required to detect the emission direction of light emitted from the lamp unit 30, and the method for detecting the emission direction is not limited. For example, the calculation unit 114 may extract a position representing a hot zone in the low beam light distribution pattern in the image, and calculate the angle of the low beam emission direction in the vertical direction from that position. Furthermore, if the light emitted from the lamp unit 30 is a high beam, for example, the calculation unit 114 may extract a position representing a hot zone in the high beam light distribution pattern, and calculate the angle of the high beam emission direction in the vertical direction from that position. Furthermore, the control device 111 may also function as the calculation unit 114.

[0071] The transceiver 115 has a configuration similar to that of the transceiver 120 provided in the vehicle 100, for example. In this embodiment, when the transceiver 115 receives a control signal transmitted from the transceiver 120, the transceiver 115 transmits the control signal to the control device 111. Furthermore, when information on the angle of the emission direction calculated by the calculation unit 114 is input from the control device 111, the transceiver 115 transmits a signal related to the angle to the outside. The transceiver 120 receives the signal related to the angle transmitted from the transceiver 115 and transmits the signal to the signal output unit 61 of the control device 60. In this way, the control signal output from the signal output unit 61 is input to the control device 111, and the signal related to the emission direction of the low beam emitted from the lamp unit 30 is input to the signal output unit 61.

[0072] Next, the operation of the control device 60 in the calibration mode will be described.

[0073] FIG. 4 is a flowchart showing an example of the operation of the control device 60 in the calibration mode in this embodiment. A program for executing the operation of this flowchart is stored in the memory 70. Therefore, the signal output unit 61 and the power supply control unit 62 of the control device 60 execute the flowchart of FIG. 4 by reading the program from the memory 70. As shown in FIG. 4, the operation of the control device 60 in this embodiment includes steps S1 to S5. Note that, in the starting state of FIG. 4, as shown in FIG. 1, the vehicle 100 is placed on the floor FL, and the measuring device 110 is placed on the floor FL in front of the vehicle 100 so as to directly face the vehicle headlamp 1 at a predetermined distance.

[0074] <Step S1> This step acquires information about the angle of the emission direction of light emitted from the lamp unit 30 in the vertical direction. In this step, first, the signal output unit 61 outputs a control signal to the first power supply circuit 81, controlling the first power supply circuit 81 to emit a low beam from the lamp unit 30. Next, the signal output unit 61 outputs a control signal to the transceiver unit 120 to instruct the measuring device 110 to perform measurement, causing the transceiver unit 120 to transmit the control signal. The control signal is received by the transceiver unit 115 of the measuring device 110 and sent to the control device 111. In response to the input of the control signal, the control device 111 measures the emission direction of light emitted from the lamp unit 30. Specifically, the control device 111 causes the light receiving unit 113 to generate image information representing an image of light irradiated on the light receiving surface 113s and output the image information to the control device 111. Next, the control device 111 outputs the information to the calculation unit 114. The calculation unit 114 extracts the position representing the elbow point EP in the image, calculates the angle of the low beam emission direction in the vertical direction from that position, and outputs information about the calculated angle to the control device 111. The control device 111 outputs the angle information to the transceiver unit 115, which outputs a signal related to the angle. The signal is received by the transceiver unit 120 and sent to the signal output unit 61. In this way, the signal output unit 61 obtains information about the angle of the emission direction of the light emitted from the lamp unit 30 and stores the information in the memory 70, although the information does not necessarily have to be stored in the memory 70. After this step, the control device 60 advances the flow to step S2.

[0075] <Step S2> This step determines the next step depending on the information about the angle of the light emission direction acquired in step S1. In this step, if the absolute value of the difference between the angle and the target angle TA is equal to or greater than the first threshold, the signal output unit 61 advances the flow to step S3. Furthermore, if the absolute value of the difference between the angle and the target angle TA is less than the first threshold, the signal output unit 61 advances the flow to step S4. The target angle TA is a target angle when adjusting the angle of the light emission direction, and is set in advance and stored in, for example, the memory 70.

[0076] FIG. 5 is a diagram illustrating the target angle and the first threshold value in this embodiment. As shown in FIG. 5 , in this embodiment, the target angle TA is zero degrees, but this is not limited to this. The first threshold value TH1 is the absolute value of the change in the angle of the light emission direction when a predetermined voltage is applied to the motor 52 for a first period of time. In this embodiment, the first period is approximately 250 ms, which is approximately the same as the electrical time constant of the motor 52, but this is not limited to this and may be longer or shorter than the electrical time constant of the motor 52. The electrical time constant of the motor 52 is the time required for the current value to rise to 63% of its saturation value after a certain voltage is applied to the motor 52 while the output shaft 52a of the motor 52 is constrained from rotating. The electrical time constant of the motor 52 can be expressed as L / R, where L is the equivalent inductance of the motor 52 and R is the winding resistance of the motor 52. Hereinafter, the electrical time constant may be simply referred to as the time constant. The predetermined voltage is, for example, 12 V or more and 16 V or less, and in this embodiment the predetermined voltage is 13.5 V. The first threshold value TH1 in this embodiment is approximately 0.20 degrees. Note that the predetermined voltage and the first threshold value TH1 are not limited.

[0077] <Step S3> This step is a step of performing first control, in which a predetermined voltage is applied to the motor 52 to control the actuator 50 so that the angle of the light emission direction approaches the target angle TA. FIG. 6 is a timing chart schematically illustrating an example of the operation of the actuator 50 when the first control is performed. The absolute value of the amount of change in the angle of the light emission direction in the first control is equal to or greater than a first threshold value TH1. In this step, the signal output unit 61 first outputs a first signal indicating the target angle TA to the power supply control unit 62. In this embodiment, the output of this first signal continues until the absolute value of the difference between the angle of the light emission direction and the target angle TA becomes less than a reference threshold value. As shown in FIG. 6 , the reference threshold value THB is smaller than the first threshold value TH1 and is the absolute value of the amount of change in the angle of the light emission direction when a predetermined voltage is applied to the motor 52 for a reference period shorter than the first period. The reference period is preferably, for example, equal to or greater than half the time constant of the motor 52 and equal to or less than two-thirds the time constant. In this embodiment, the reference period is approximately 1 / 2 of the time constant, and the reference threshold value THB is approximately 0.05 degrees. Note that the reference period and the reference threshold value THB are not limited to these values.

[0078] In this embodiment, the power supply control unit 62 controls the second power supply circuit 82 based on the input first signal and the signal input from the position sensor 57 to apply a predetermined voltage to the motor 52 and control the actuator 50 so that the angle of the light emission direction approaches the target angle TA. When the absolute value of the difference between the angle of the light emission direction and the target angle becomes less than a reference threshold value THB, the power supply control unit 62 stops applying the predetermined voltage to the motor 52, terminates control of the actuator 50, and outputs a signal indicating the end of control to the signal output unit 61. The signal output unit 61 terminates output of the first signal based on this signal. Note that the period during which the signal output unit 61 outputs the first signal may be a predetermined period, and the power supply control unit 62 does not need to output a signal indicating the end of control to the signal output unit 61. In this case, the period only needs to be longer than the period required for the absolute value of the difference between the angle of the light emission direction and the target angle to become less than the reference threshold value through control of the actuator 50. Furthermore, in this embodiment, the power supply control unit 62 connects the motor 52 to ground after finishing applying the predetermined voltage to the motor 52. As a result, the induced electromotive force generated in the motor 52 is short-circuited, and a current flows through the motor 52. The direction of this current is opposite to that when the motor 52 was being rotated, and a braking force is applied to the motor 52. In other words, a so-called short brake effect occurs in the motor 52, and the rotation of the motor 52 stops. Note that the power supply control unit 62 does not need to connect the motor 52 to ground when finishing applying the predetermined voltage to the motor 52. After this step, the signal output unit 61 disables the emission of low beams from the lamp unit 30, and the calibration mode ends.

[0079] <Step S4> This step determines the next step depending on the information about the angle of the light emission direction acquired in step S1. In this step, if the absolute value of the difference between the angle and the target angle TA is less than the reference threshold value THB, the signal output unit 61 stops the emission of low beams from the lamp unit 30 and ends the calibration mode. Also, if the absolute value of the difference between the angle and the target angle TA is equal to or greater than the reference threshold value THB, the signal output unit 61 advances the flow to step S5.

[0080] <Step S5> This step is a second control step for controlling the actuator 50 by applying a predetermined voltage to the motor 52 at least once for a second period that is equal to or less than twice the reference period until the absolute value of the difference between the angle of the light emission direction and the target angle TA becomes less than the reference threshold THB. In this step, the signal output unit 61 outputs a second signal to the power supply control unit 62 at least once for a second period that is equal to or less than twice the reference period, the second signal relating to a specific direction from the angle of the emission direction toward the target angle TA. In this embodiment, the second signal is a signal indicating a specific angle SA where the absolute value of the difference between the target angle TA on the angle side of the emission direction and the target angle TA on the opposite side is equal to or greater than the first threshold TH1. This signal output is performed until the absolute value of the difference between the angle of the light emission direction and the target angle TA becomes less than the reference threshold THB. 5, in this embodiment, for example, when the angle of the light emission direction is less than −0.05 degrees and equal to or greater than −0.20 degrees, the specific angle SA is an angle of +0.20 degrees or greater, and in this embodiment, it is 0.30 degrees. Also, when the angle of the light emission direction is equal to or greater than +0.05 degrees and equal to or less than +0.20 degrees, the specific angle SA is an angle of −0.20 degrees or less, and in this embodiment, it is −0.30 degrees. Note that the specific angle SA may be any angle as long as the absolute value of the difference between the target angle TA on the angle side of the emission direction and the target angle TA on the opposite side is equal to or greater than the first threshold value TH1.

[0081] The second period is preferably equal to or shorter than the reference period. In this embodiment, as shown in FIG. 7 , when a predetermined voltage is applied to the motor 52, the increase in the rotational speed of the motor 52 per unit time gradually increases and then gradually decreases to zero. In this embodiment, the period T3 from when the predetermined voltage is applied to the motor 52 until the increase begins to decrease is preferably shorter than the reference period, and the second period T2 is preferably longer than this period T3. In this embodiment, the second period T2 is equal to or shorter than the reference period, is greater than or equal to ⅕ of the time constant and less than or equal to ⅓ of the time constant, is longer than the period T3, and is approximately 100 ms. Note that the second period T2 is not limited as long as it is equal to or shorter than twice the reference period.

[0082] When a second signal indicating a specific angle SA is input, the power supply control unit 62 controls the actuator 50 by applying a predetermined voltage to the motor 52 during the period in which the second signal is input, so that the angle of the light emission direction changes to a specific direction. As described above, the power supply control unit 62 outputs the second signal indicating the specific angle SA to the power supply control unit 62 for the second period T2 at least once until the absolute value of the difference between the angle of the light emission direction and the target angle TA becomes less than the reference threshold value THB. Therefore, the second control described above is performed. Furthermore, in this embodiment, the power supply control unit 62 connects the motor 52 to ground each time the voltage application for applying a predetermined voltage to the motor 52 for the second period T2 ends. Therefore, each time the voltage application ends, a so-called short brake effect occurs in the motor 52, causing the motor 52 to stop rotating. It should be noted that the power supply control unit 62 does not necessarily have to connect the motor 52 to ground each time the voltage application ends.

[0083] In this embodiment, the absolute value of the change in the angle of the light emission direction due to the application of a predetermined voltage to the motor 52 during the second period T2 is approximately 0.03 degrees. The signal output unit 61 in this embodiment calculates the number of signal outputs from the absolute value of the difference between the angle of the light emission direction and the target angle TA, and outputs the signal the calculated number of times. For example, the signal output unit 61 determines the number of signal outputs as the quotient obtained by dividing the absolute value of the difference between the angle of the light emission direction and the target angle TA by 0.03. By outputting the signal this number of times, the absolute value of the difference between the angle of the light emission direction and the target angle TA becomes less than the reference threshold value THB. Note that the method for calculating the number of signal outputs is not limited.

[0084] 8 is a timing chart schematically illustrating an example of the operation of the actuator 50 when the second control is performed. In the example shown in FIG. 8, the absolute value of the difference between the angle of the light emission direction and the target angle TA is approximately 0.1 degrees, which is equal to or greater than the reference threshold THB and less than the first threshold TH1, so the second control is performed. In this example, the second control performs a signal output for outputting a second signal indicating the specific angle SA to the power supply control unit 62 for the second period T2 three times, and a voltage application for applying a predetermined voltage to the motor 52 for the second period T2 three times.

[0085] In this embodiment, when signal output is performed multiple times, the period T4 between signal outputs is shorter than the second period T2, but longer than half the second period T2, i.e., approximately 90 ms. The second period T2 for each signal output is the same. The signal output unit 61 stops emitting low beams from the lamp unit 30 and ends the calibration mode.

[0086] In this way, in the calibration mode of this embodiment, one of the first control and the second control is performed so that the absolute value of the difference between the angle of the emission direction of light emitted from the lighting unit 30 and the target angle TA is less than the reference threshold value THB.

[0087] Next, the operation of the control device 60 in the leveling mode, which is a mode other than the calibration mode, will be described.

[0088] 9 is a flowchart showing an example of the operation of the control device 60 in the leveling mode in this embodiment. A program for executing the operation of this flowchart is stored in the memory 70. Therefore, the signal output unit 61 and the power supply control unit 62 of the control device 60 execute the flowchart of FIG. 9 by reading the program from the memory 70. As shown in FIG. 9, the operation of the control device 60 in this embodiment includes steps S21 to S25. This mode is a mode in which the angle of the emission direction of light from the lamp unit 30 is changed in accordance with the tilt of the vehicle 100 in the longitudinal direction.

[0089] <Step S21> This step is a step for acquiring information on the tilt angle of the vehicle 100 in the longitudinal direction. In this step, the signal output unit 61 acquires information related to the tilt angle of the vehicle 100 in the longitudinal direction from the tilt sensor 130 and stores the information in the memory 70. However, the information does not have to be stored in the memory 70. After this step, the control device 60 advances the flow to step S2.

[0090] <Step S22> This step determines the next step depending on the tilt angle information acquired in step S21. As shown in FIG. 5 , the actuator 50 has an angular range RA of the emission direction that can be changed. In this embodiment, the angular range RA is −3.0 degrees to +3.0 degrees. In this step, the signal output unit 61 proceeds to step S23 if the absolute value of the difference between the target angle TA and one of the two ends of the angular range RA of the emission direction that can be changed by the actuator 50 is equal to or less than a second threshold value that is equal to or greater than the first threshold value TH1. Note that in this embodiment, the second threshold value TH2 is the same as the first threshold value TH1. Furthermore, the signal output unit 61 proceeds to step S24 if the absolute value of the difference between the target angle TA and both the upper and lower limits of the angle of the emission direction that can be changed by the actuator 50 is equal to or greater than the second threshold value TH2.

[0091] Here, when the vehicle 100 tilts in the longitudinal direction, the vehicle headlamp 1 also tilts along with the vehicle 100. For this reason, for example, when the vehicle 100 tilts downward, the angle of the light emission direction from the lamp unit 30 also tilts downward from the target angle TA by the same amount, and when the vehicle 100 tilts upward, the angle of the light emission direction from the lamp unit 30 also tilts upward from the target angle TA by the same amount. For this reason, the target angle TA in this mode is the angle obtained by subtracting the tilt angle of the vehicle 100 from the target angle TA in the calibration mode.

[0092] <Step S23> This step is a step in which no voltage is applied to the motor 52 and the actuator 50 is not controlled. In this step, the signal output unit 61 does not output a signal to the power supply control unit 62. Therefore, the power supply control unit 62 does not apply a voltage to the motor 52 and does not control the actuator 50. After this step, the signal output unit 61 ends the leveling mode.

[0093] <Step S24> This step determines the next step depending on the tilt angle information acquired in step S21. In this step, if the absolute value of the difference between the tilt angle and the target angle TA is equal to or greater than the first threshold value TH1, the signal output unit 61 proceeds to step S25. On the other hand, if the absolute value of the difference between the tilt angle and the target angle TA is less than the first threshold value TH1, the signal output unit 61 proceeds to step S23.

[0094] <Step S25> Similar to step S3, this step is a step of performing third control in which a predetermined voltage is applied to the motor 52 to control the actuator 50 so that the angle of the light emission direction approaches the target angle TA. In this step, first, the signal output unit 61 outputs a first signal indicating the target angle TA and a signal indicating the tilt angle to the power supply control unit 62. In this embodiment, the output of the first signal and the signal indicating the tilt angle are continued until the absolute value of the difference between the angle of the light emission direction and the target angle TA becomes less than the reference threshold value THB.

[0095] In this embodiment, the power supply control unit 62 controls the second power supply circuit 82 based on the input first signal, the signal indicating the tilt angle, and the signal input from the position sensor 57 to apply a predetermined voltage to the motor 52 and control the actuator 50 so that the angle of the light emission direction approaches the target angle TA. Note that the angle of the light emission direction here is the angle of the light emission direction after adjustment in the calibration mode. When the absolute value of the difference between the angle of the light emission direction and the target angle becomes less than the reference threshold value THB, the power supply control unit 62 stops applying the predetermined voltage to the motor 52, terminates control of the actuator 50, and outputs a signal indicating the end of control to the signal output unit 61. The signal output unit 61 terminates output of the first signal based on this signal. Note that the period during which the signal output unit 61 outputs the first signal may be a predetermined period, and the power supply control unit 62 does not have to output a signal indicating the end of control to the signal output unit 61. In this case, the period should be longer than the period required for the absolute value of the difference between the angle of the light emission direction and the target angle to become less than the reference threshold value THB through control of the actuator 50. After this step, the signal output unit 61 ends the leveling mode.

[0096] In this way, in the leveling mode of this embodiment, if the absolute value of the difference between the angle of the emission direction and the target angle TA is equal to or greater than the first threshold value TH1, a predetermined voltage is applied to the motor 52, and the angle of the emission direction of light emitted from the lighting unit 30 approaches the target angle TA. Also, if the absolute value of the difference between the angle of the emission direction and the target angle TA is less than the first threshold value TH1, no voltage is applied to the motor, and the actuator 50 is not controlled.

[0097] As described above, the control device 60 of this embodiment as a first aspect controls the actuator 50, which transmits the torque of the motor 52 to the lamp unit 30 to change the orientation of the lamp unit 30 so that the light emission direction is tilted along a plane VP that is approximately parallel to the vertical plane, is switchable between a calibration mode and a mode other than the calibration mode, and includes a signal output unit 61 and a power supply control unit 62. In the calibration mode, when the absolute value of the difference between the angle of the emission direction and the target angle TA is less than the first threshold value TH1 and equal to or greater than the reference threshold value THB, the signal output unit 61 outputs a second signal related to a specific direction from the angle of the emission direction toward the target angle TA to the power supply control unit 62 for a second period T2, one or more times until the absolute value of the difference between the angle of the emission direction and the target angle TA becomes less than the reference threshold value THB. The first threshold TH1 is the absolute value of the amount of change in the angle of the emission direction when a predetermined voltage is applied to the motor 52 for a first period, the reference threshold THB is the absolute value of the amount of change in the angle of the emission direction when a predetermined voltage is applied to the motor 52 for a reference period shorter than the first period, and the second period T2 is equal to or less than twice the reference period. In the calibration mode, when a second signal relating to a specific direction is input, the power supply control unit 62 controls the actuator by applying a predetermined voltage to the motor 52 for the period during which the signal is input, so that the angle of the emission direction changes in the specific direction. In a leveling mode, which is a mode other than the calibration mode, when the absolute value of the difference between the angle of the emission direction and the target angle TA is less than the first threshold TH1 and a second signal relating to the specific direction is input, the power supply control unit 62 does not apply voltage to the motor 52.

[0098] Furthermore, a program of the present embodiment as a second aspect is a program that controls the actuator 50, which transmits the torque of the motor 52 to the lamp unit 30 and can change the orientation of the lamp unit 30 so that the light emission direction is tilted along a plane VP that is approximately parallel to the vertical plane, is switchable between a calibration mode and a mode other than the calibration mode, and is executed by a control device 60 that includes a signal output unit 61 and a power supply control unit 62. In the calibration mode, this program causes the signal output unit 61 to execute a step of outputting, to the power supply control unit 62, a second signal relating to a specific direction from the angle of the emission direction toward the target angle TA for a second period T2, one or more times until the absolute value of the difference between the angle of the emission direction and the target angle TA becomes less than the reference threshold value THB, when the absolute value of the difference between the angle of the emission direction and the target angle TA is less than a first threshold value TH1 and equal to or greater than a reference threshold value THB. The first threshold TH1 is the absolute value of the amount of change in the angle of the emission direction when a predetermined voltage is applied to the motor 52 for a first period, the reference threshold THB is the absolute value of the amount of change in the angle of the emission direction when a predetermined voltage is applied to the motor 52 for a reference period shorter than the first period, and the second period T2 is equal to or less than twice the reference period. This program causes the power supply control unit 62 to execute a step of controlling the actuator by applying a predetermined voltage to the motor 52 for the period during which the signal is input, so that the angle of the emission direction changes in the specific direction, when a second signal related to a specific direction is input. This program causes the power supply control unit 62 to execute a step of not applying voltage to the motor 52 when the absolute value of the difference between the angle of the emission direction and the target angle TA is less than the first threshold TH1 and when a second signal related to the specific direction is input.

[0099] Furthermore, the vehicle headlamp 1 of this embodiment as a third aspect includes an actuator 50 and a control device 60 that controls the actuator 50. The actuator 50 transmits torque of a motor 52 to the lamp unit 30 to change the orientation of the lamp unit 30 so that the light emission direction is tilted along a plane VP that is generally parallel to a vertical plane. The control device 60 is switchable between a calibration mode and a mode other than the calibration mode, and includes a signal output unit 61 and a power supply control unit 62. In the calibration mode, when the absolute value of the difference between the emission direction angle and the target angle TA is less than a first threshold value TH1 and greater than or equal to a reference threshold value THB, the signal output unit 61 outputs a second signal related to a specific direction from the emission direction angle toward the target angle TA to the power supply control unit 62 for a second period T2 one or more times until the absolute value of the difference between the emission direction angle and the target angle TA becomes less than the reference threshold value THB. The first threshold TH1 is the absolute value of the amount of change in the angle of the emission direction when a predetermined voltage is applied to the motor 52 for a first period, the reference threshold THB is the absolute value of the amount of change in the angle of the emission direction when a predetermined voltage is applied to the motor 52 for a reference period shorter than the first period, and the second period T2 is equal to or less than twice the reference period. In the calibration mode, when a second signal relating to a specific direction is input, the power supply control unit 62 controls the actuator by applying a predetermined voltage to the motor 52 for the period during which the signal is input, so that the angle of the emission direction changes in the specific direction. In a leveling mode, which is a mode other than the calibration mode, when the absolute value of the difference between the angle of the emission direction and the target angle TA is less than the first threshold TH1 and a second signal relating to the specific direction is input, the power supply control unit 62 does not apply voltage to the motor 52.

[0100] In the control device 60, the program, and the vehicle headlamp 1 according to the first to third aspects of the present embodiment, in a leveling mode other than the calibration mode, if the absolute value of the difference between the emission direction angle and the target angle TA is less than the first threshold value TH1, the orientation of the actuator 50 is not changed. This can prevent malfunction of the actuator 50. However, in the calibration mode, if the absolute value of the difference between the emission direction angle and the target angle TA is less than the first threshold value TH1 and equal to or greater than the reference threshold value THB, the emission direction angle is changed to approach the target angle TA one or more times until the absolute value of the difference between the emission direction angle and the target angle TA becomes less than the reference threshold value THB. This means that in the calibration mode, the emission direction angle can approach the target angle TA even if the absolute value of the difference between the emission direction angle and the target angle TA is less than the first threshold value TH1 and equal to or greater than the reference threshold value THB. Therefore, according to the control device 60, the program, and the vehicle headlamp 1 of this embodiment, even in such a case, the accuracy of adjusting the emission direction of the light emitted from the lamp unit 30 can be improved.

[0101] In the control device 60, the program, and the vehicle headlamp 1 of this embodiment, in a leveling mode other than the calibration mode, the power supply control unit 62 does not apply voltage to the motor 52 when the absolute value of the difference between the target angle TA and one of the two ends of the angular range RA of the emission direction that can be changed by the actuator 50 is equal to or smaller than a second threshold TH2 that is equal to or larger than a first threshold TH1. Therefore, when the target angle TA is close to one of the two ends of the angular range RA of the emission direction that can be changed by the actuator 50, the orientation of the actuator 50 can be prevented from changing, which can prevent, for example, malfunctions of the actuator 50. From this perspective, in at least one of the calibration mode and a mode other than the calibration mode, the power supply control unit 62 does not apply voltage to the motor 52 when the absolute value of the difference between the target angle TA and one of the two ends of the angular range RA of the emission direction that can be changed by the actuator 50 is equal to or smaller than a second threshold TH2 that is equal to or larger than the first threshold TH1. For example, the power supply control unit 62 may not apply voltage to the motor 52 in the calibration mode as well. However, the power supply control unit 62 may apply voltage to the motor 52 if the absolute value of the difference between the target angle TA and one of the two ends of the angle range RA of the emission direction that can be changed by the actuator 50 is less than or equal to a second threshold value TH2 that is greater than or equal to the first threshold value TH1.

[0102] In the control device 60, program, and vehicle headlamp 1 of this embodiment, when signal outputs are performed multiple times in the second control, the period T4 between signal outputs is shorter than the second period T2. Therefore, the control device 60, program, and vehicle headlamp 1 of this embodiment can prevent the time required to adjust the light emission direction from becoming long. Note that the period T4 may be the same as the second period T2 or may be longer than the second period T2. When the period T4 is longer than the second period T2, it can be easier to measure the light emission direction between signal outputs in the second control.

[0103] Second Embodiment Next, a second embodiment as the first to third aspects of the present invention will be described in detail. Note that components that are the same as or equivalent to those in the first embodiment will be assigned the same reference numerals and will not be described again unless otherwise specified. In this embodiment, the signal output by the signal output unit 61 is different from the signal output by the signal output unit 61 in the first embodiment. Furthermore, the flow of the calibration mode in this embodiment is the same as the flow in the first embodiment, except for steps S3 and S5. Therefore, steps S3 and S5 will be described with reference to FIG. 4, and a description of steps other than steps S3 and S5 will be omitted.

[0104] <Step S3> In this embodiment, as in the first embodiment, this step is a step of performing first control, in which a predetermined voltage is applied to the motor 52 to control the actuator 50 so that the angle of the light emission direction approaches the target angle TA. Therefore, the absolute value of the amount of change in the angle of the light emission direction in the first control is equal to or greater than the first threshold value TH1. However, in this step of the present embodiment, the signal output unit 61 first outputs a first signal to the power supply control unit 62, the first signal indicating the value obtained by subtracting the angle of the emission direction from the target angle TA. In other words, the first signal in this embodiment is a signal indicating the amount of change in the angle. For example, if the target angle TA is +0.1 degrees and the angle of the emission direction is -0.1 degrees, the value indicated by the first signal is 0.2 degrees. Furthermore, if the target angle TA is +0.1 degrees and the angle of the emission direction is +0.1 degrees, the value indicated by the first signal is 0.0 degrees.

[0105] In this embodiment, similar to the first embodiment, the power supply control unit 62 controls the second power supply circuit 82 based on the input first signal and the signal input from the position sensor 57 to apply a predetermined voltage to the motor 52 and control the actuator 50 so that the angle of the light emission direction approaches the target angle TA. When the absolute value of the difference between the angle of the light emission direction and the target angle becomes less than the reference threshold value THB, the power supply control unit 62 stops applying the predetermined voltage to the motor 52, ends control of the actuator 50, and outputs a signal indicating the end of control to the signal output unit 61. Based on this signal, the signal output unit 61 ends output of the first signal. After this step, the signal output unit 61 disables low beam emission from the lamp unit 30 and ends the calibration mode.

[0106] <Step S5> In this embodiment, similar to the first embodiment, this step is a step of performing second control to control the actuator 50 by applying a predetermined voltage to the motor 52 for a second period T2, which is equal to or less than twice the reference period, one or more times until the absolute value of the difference between the angle of the light emission direction and the target angle TA becomes less than the reference threshold THB. In this step in the first embodiment, the signal output unit 61 outputs a second signal relating to a specific direction from the angle of the emission direction toward the target angle TA to the power supply control unit 62 for a second period T2, which is equal to or less than twice the reference period, one or more times. In the first embodiment, the second signal was a signal indicating a specific angle SA, at which the absolute value of the difference between the target angle TA on the angle side of the emission direction and the target angle TA on the opposite side of the emission direction is equal to or greater than the first threshold TH1. However, in this embodiment, the second signal is a signal indicating a value obtained by subtracting the angle of the emission direction from a specific angle SA, at which the absolute value of the difference between the target angle TA on the angle side of the emission direction and the target angle TA on the opposite side of the emission direction is equal to or greater than the first threshold TH1. For example, if the angle of the emission direction is -0.1 and the specific angle SA is +0.30, the second signal is 0.4 degrees. Also, if the angle of the emission direction is +0.1 and the specific angle SA is -0.30, the second signal is -0.4 degrees. This signal output is continued until the absolute value of the difference between the angle of the emission direction of light and the target angle TA becomes less than the reference threshold value THB.

[0107] When the second signal is input, the power supply control unit 62 controls the actuator 50 by applying a predetermined voltage to the motor 52 for the period during which the second signal is input, so that the angle of the emission direction changes in a specific direction, as in the first embodiment. As described above, a second signal indicating the value obtained by subtracting the angle of the emission direction from the specific angle SA is output to the power supply control unit 62 for the second period T2 one or more times until the absolute value of the difference between the angle of the light emission direction and the target angle TA becomes less than the reference threshold value THB. Therefore, the above-mentioned second control is performed.

[0108] In the control device 60, program, and vehicle headlamp 1 of this embodiment, similar to the control device 60, program, and vehicle headlamp 1 of the first embodiment, during the leveling mode, if the absolute value of the difference between the angle of the emission direction and the target angle TA is less than the first threshold value TH1, the orientation of the actuator 50 is not changed, thereby preventing malfunction of the actuator. Furthermore, in the calibration mode, even if the absolute value of the difference between the angle of the emission direction and the target angle TA is less than the first threshold value TH1 and equal to or greater than the reference threshold value THB, the angle of the emission direction can be brought closer to the target angle TA. Therefore, with the above-described control device 60, program, and vehicle headlamp 1, even in such a case, the accuracy of adjusting the emission direction of light emitted from the lamp unit 30 can be improved. The second signal relating to the specific direction is not limited.

[0109] Although the first to third aspects of the present invention have been described using the first and second embodiments as examples, the first to third aspects of the present invention are not limited to these.

[0110] For example, in the first and second embodiments, the actuator 50 is described as being capable of changing the orientation of the lamp unit 30 so that the light emission direction tilts along a plane VP generally parallel to the vertical plane. However, the actuator 50 may be configured to transmit the torque of the motor 52 to the lamp unit 30 and change the orientation of the lamp unit 30 so that the light emission direction tilts along a predetermined plane. For example, the configuration for transmitting the torque of the motor 52 to the lamp unit 30 is not limited. Furthermore, the predetermined plane is not limited to the plane VP generally parallel to the vertical plane. For example, the actuator 50 may be configured to change the orientation of the lamp unit 30 so that the light emission direction tilts along a plane generally parallel to the horizontal plane. Although not illustrated, an example of such an actuator 50 is a configuration including an output shaft extending in the vertical direction and having an upper end fixed to the lower side of the lamp unit 30. In this case, the torque of the motor 52 rotates the output shaft about its central axis. With this configuration, the direction of light emitted from the lighting unit 30 can be adjusted in the left-right direction along a plane that is roughly parallel to the horizontal plane.

[0111] Furthermore, in the first and second embodiments, when a signal output is performed multiple times, the second period T2 is the same for each signal output. However, the second period T2 is not limited. FIG. 10 is a timing chart schematically illustrating an example of the operation of the actuator 50 when the second control in Modification 1 is performed. In the example shown in FIG. 10, when a signal output is performed multiple times in the second control, the second period T2 is shorter for the later signal output. According to this modification, the amount of change in the orientation of the lamp unit 30 at the signal output can be made smaller for later signal outputs. Therefore, the closer the angle of the light emission direction to the target angle TA, the smaller the amount of change in the orientation of the lamp unit 30 can be, making it easier to bring the angle of the light emission direction closer to the target angle TA.

[0112] When the signal output is performed multiple times in the second control, the second period T2 may be shorter in the signal output that is performed last, or may be longer in the signal output that is performed last.

[0113] In the first and second embodiments, the angle of the light emission direction is measured before the second control is performed, but this measurement is not performed during the second control. However, for example, if the number of signal outputs in the second control is multiple, the angle of the light emission direction may be measured each time a signal is output, and at least one of the predetermined voltage and the second period T2 for the next signal output may be determined from the measured angle of the light emission direction. The above-described first modification is particularly useful in such a configuration.

[0114] In the first and second embodiments, the weight of the lamp unit 30 generates torque in the lamp unit 30 such that the light emission direction changes downward. However, the direction of the torque generated in the lamp unit 30 by the weight of the lamp unit 30 is not limited. Furthermore, the position of the center of gravity 30G of the lamp unit 30 is not limited.

[0115] Furthermore, in the first and second embodiments, in the leveling mode, the power supply control unit 62 did not apply voltage to the motor 52 when the absolute value of the difference between the angle of the emission direction and the target angle TA was less than the first threshold value TH1. However, the operation of the power supply control unit 62 not applying voltage to the motor 52 when the absolute value of the difference between the angle of the emission direction and the target angle TA is less than the first threshold value TH1 may be performed during at least a portion of a mode other than the calibration mode. For example, during the entire period of a mode other than the calibration mode, the power supply control unit 62 may not apply voltage to the motor 52 when the absolute value of the difference between the angle of the emission direction and the target angle TA is less than the first threshold value TH1 and a second signal related to a specific direction is input.

[0116] Furthermore, there is no limitation to the flowchart of the operation of the control device 60 in the calibration mode and the leveling mode of the vehicle headlamp 1. For example, after step S3 in the first embodiment, the signal output unit 61 may return the flow to step S1.

[0117] Furthermore, in the adjustment system SY of the first and second embodiments, the measuring device 110 receives light emitted from the lighting unit 30, measures the emission direction of the light from the lighting unit 30, and outputs a signal related to the emission direction of the light from the lighting unit 30 to the control device 60. However, the device for measuring the emission direction of the light from the lighting unit 30 is not limited. For example, if the emission direction of the light changes vertically as the lighting unit 30 tilts along a plane VP that is approximately parallel to the vertical plane as described above, the tilt angle of the lighting unit 30 in the vertical direction is also the angle of the emission direction of the light in the vertical direction. Therefore, for example, a sensor that tilts along the plane VP together with the lighting unit 30 and outputs a signal related to the tilt angle of the lighting unit 30 indirectly measures the angle of the emission direction of the light within the plane VP, and the signal output from the sensor is a signal related to the emission direction of the light. Therefore, such a sensor may output a signal related to the emission direction of the light to the control device 60. An example of such a sensor is a three-axis acceleration sensor attached to the lighting unit 30.

[0118] In the first and second embodiments, the vehicle lamp is described as a vehicle headlamp 1. However, the vehicle lamp is not limited to a vehicle headlamp, and may be, for example, a road surface drawing device that draws a predetermined image on a road surface by emitting light.

[0119] (Third Embodiment) Next, a third embodiment will be described as fourth to sixth aspects of the present invention. Components that are the same as or equivalent to those in the first embodiment will be assigned the same reference numerals and will not be described again unless otherwise specified. Fig. 11 is a schematic diagram showing an adjustment system that adjusts the emission direction of light emitted from a vehicle lamp according to this embodiment. The vehicle lamp of this embodiment is a vehicle headlamp 1, similar to the first embodiment. Fig. 12 is a diagram that schematically shows the vehicle headlamp 1 according to this embodiment.

[0120] In this embodiment, the control device 60 is electrically connected to the memory 70, the first power supply circuit 81, the second power supply circuit 82, and the transceiver unit 120. In this embodiment, the memory 70 and the control device 60 may be provided in an integrated package. In this embodiment, the control device 60 reads out programs and information stored in the memory 70. In addition, the memory 70 stores information in response to instructions from the control device 60.

[0121] The control device 60 of this embodiment reads out a program for controlling the lighting unit 30 from the memory 70, and controls the lighting unit 30 by outputting a signal to the first power supply circuit 81 and controlling the first power supply circuit 81.

[0122] In addition, the control device 60 of this embodiment reads out a program for controlling the actuator 50 from the memory 70 , and controls the actuator 50 by outputting a signal to the second power supply circuit 82 and controlling the second power supply circuit 82 .

[0123] Furthermore, the control device 60 of this embodiment outputs a control signal to the transceiver unit 120 provided in the vehicle 100 to instruct the measuring device 110 to perform measurement.

[0124] In the present embodiment, the control device 60, the memory 70, the first power supply circuit 81, and the second power supply circuit 82 are disposed outside the housing 20. However, at least one of these may be housed in the housing 20, and the second power supply circuit 82 may be housed in the housing space of the case 51 of the actuator 50. The control device 60 may include at least one of the first power supply circuit 81 and the second power supply circuit 82, and may be included in a vehicle control device that controls the engine of the vehicle 100, etc. The first power supply circuit 81 and the second power supply circuit 82 may be provided in an integrated package. The control device 60, the first power supply circuit 81, and the second power supply circuit 82 may be provided in an integrated package. At least one of the first power supply circuit 81 and the second power supply circuit 82 and the memory 70 may be provided in an integrated package, and the control device 60, the memory 70, the first power supply circuit 81, and the second power supply circuit 82 may be provided in an integrated package.

[0125] In this embodiment, a control signal output from the control device 60 is input to the control device 111 of the measuring device 110 , and a signal relating to the emission direction of the low beam emitted from the lamp unit 30 is input to the control device 60 .

[0126] Next, calibration of the vehicle headlamp 1 of this embodiment will be described.

[0127] The flowchart of the operation of the control device 60 in the calibration of the vehicle headlamp 1 of this embodiment is the same as the flowchart of the operation of the control device 60 in the calibration mode of the first embodiment shown in Fig. 4. Therefore, the description will be made with reference to Fig. 4.

[0128] <Step S1> In this embodiment, as in the first embodiment, this step is a step for acquiring information on the angle of the emission direction of light emitted from the lamp unit 30 in the vertical direction. In this embodiment, first, the control device 60 controls the lamp unit 30 to emit a low beam from the lamp unit 30. Specifically, the control device 60 outputs a control signal to the first power supply circuit 81 to control the first power supply circuit 81, thereby causing the lamp unit 30 to emit a low beam. Next, the control device 60 outputs a control signal to the transceiver 120 to instruct the measuring device 110 to perform measurement, and causes the transceiver 120 to transmit the control signal. The control signal is received by the transceiver 115 of the measuring device 110 and sent to the control device 111. The control device 111 measures the emission direction of light emitted from the lamp unit 30 in response to the input of the control signal. Specifically, the control device 111 causes the light receiving unit 113 to generate image information representing an image of light irradiated onto the light receiving surface 113s and output the image information to the control device 111. Next, the control device 111 outputs the image information to the calculation unit 114. The calculation unit 114 extracts a position representing the elbow point EP in the image, calculates the angle of the low beam emission direction in the vertical direction from the extracted position, and outputs the calculated angle information to the control device 111. The control device 111 outputs the angle information to the transceiver unit 115, which then outputs a signal related to the angle. The signal is received by the transceiver unit 120 and sent to the control device 60. In this way, the control device 60 obtains information on the angle of the emission direction of light emitted from the lamp unit 30 and stores the information in the memory 70; however, the information does not necessarily have to be stored in the memory 70. After this step, the control device 60 advances the flow to step S2.

[0129] <Step S2> In this embodiment, as in the first embodiment, this step is a step in which the next step is changed depending on the information on the angle of the light emission direction acquired in step S1. In this embodiment, the control device 60 advances the flow to step S3 if the absolute value of the difference between the angle and the target angle TA is equal to or greater than a first threshold. Also, the control device 60 advances the flow to step S4 if the absolute value of the difference between the angle and the target angle TA is less than the first threshold.

[0130] FIG. 13 is a diagram illustrating the target angle and the first threshold value in this embodiment. As shown in FIG. 13 , in this embodiment, the target angle TA is zero degrees, but is not limited to this. The first threshold value TH1 is the absolute value of the amount of change in the angle of the light emission direction when a predetermined first voltage is applied to the motor 52 for a period equal to the electrical time constant of the motor 52. FIG. 14 is a diagram illustrating the electrical time constant of the motor 52, showing the change in current value over time when a first voltage is applied to the motor 52 while the output shaft 52a of the motor 52 is constrained to prevent rotation. Note that the electrical time constant may be referred to as the time constant below. As described in the first embodiment, the time constant τ of the motor 52 is the time required for the current value to rise to 63% of its saturation value after a predetermined voltage is applied to the motor 52 while the output shaft 52a of the motor 52 is constrained to prevent rotation. The time constant τ of the motor 52 can be expressed as L / R, where L is the equivalent inductance of the motor 52 and R is the winding resistance of the motor 52. In this embodiment, the time constant τ of the motor 52 is approximately 250 ms. The first voltage is, for example, 12 V or more and 16 V or less, and the predetermined voltage in this embodiment is 13.5 V. The first threshold TH1 in this embodiment is approximately 0.20 degrees. Note that the time constant τ, the first voltage, and the first threshold TH1 are not limited.

[0131] <Step S3> Unlike the first embodiment, this step in the present embodiment is a step of performing first control to control the actuator 50 by applying a first voltage to the motor 52 for a first period equal to or greater than the time constant τ so that the angle of the light emission direction approaches the target angle TA. In this step, the control device 60 performs the first control by outputting a control signal to the second power supply circuit 82 to control the second power supply circuit 82. In this embodiment, the control device 60 performs the first control based on information about the angle of the light emission direction acquired in step S1. In this embodiment, the first period is longer the greater the absolute value of the difference between the angle of the light emission direction acquired in step S1 and the target angle TA. After this step, the control device 60 returns the flow to step S1.

[0132] <Step S4> In this embodiment, as in the first embodiment, this step is a step in which the next step is changed depending on the information on the angle of the light emission direction acquired in step S1. In this embodiment, if the absolute value of the difference between the angle and the target angle TA is less than a reference threshold, the control device 60 stops the emission of low beams from the lamp unit 30 and ends control of the calibration. Furthermore, if the absolute value of the difference between the angle and the target angle TA is equal to or greater than the reference threshold, the control device 60 advances the flow to step S5.

[0133] Generally, an actuator that can change the orientation of a lamp unit using motor torque may have difficulty precisely adjusting the orientation of the lamp unit. As shown in FIG. 13 , the reference threshold THB is smaller than the first threshold TH1 and is the absolute value of the change in the angle of the light emission direction when a second power is applied to the motor 52 for a reference period shorter than the time constant τ. The reference period is preferably, for example, greater than or equal to half the time constant τ of the motor 52 and less than or equal to two-thirds of the time constant τ. In this embodiment, the reference period is approximately half the time constant τ, and the reference threshold THB is approximately 0.05 degrees. Furthermore, in this embodiment, the second voltage is smaller than the first voltage, approximately two-thirds the first voltage, or 10V. The reference threshold THB and the second voltage are not limited.

[0134] <Step S5> In this embodiment, unlike the first embodiment, this step is a step of performing second control to control the actuator 50 by applying a second voltage to the motor 52 for a second period, which is equal to or less than twice the reference period, at least once until the absolute value of the difference between the angle of the light emission direction and the target angle TA becomes less than the reference threshold THB. In this step, the control device 60 performs the second control by outputting a control signal to the second power supply circuit 82 to control the second power supply circuit 82. The second period is preferably equal to or less than the reference period. Also, in this embodiment, as in the first embodiment, when the first voltage is applied to the motor 52, as shown in FIG. 7 , the increase in the rotational speed of the motor 52 per unit time gradually increases and then gradually decreases to zero. In this embodiment, the period T3 from when the first voltage is applied to the motor 52 until the increase begins to decrease is preferably shorter than the reference period, and the second period T2 is preferably longer than the period T3. In this embodiment, the second period T2 is equal to or shorter than the reference period, is equal to or longer than ⅕ of the time constant τ and equal to or shorter than ⅓ of the time constant τ, is longer than the period T3, and is approximately 100 ms. Note that the second period T2 is not limited as long as it is equal to or shorter than twice the reference period.

[0135] In this embodiment, the absolute value of the change in the angle of the light emission direction due to the voltage application when the second voltage is applied to the motor 52 for the second period T2 is approximately 0.03 degrees. The control device 60 of this embodiment calculates the number of times to apply voltage from the absolute value of the difference between the angle of the light emission direction and the target angle TA, and controls the second power supply circuit 82 to apply the voltage the calculated number of times. For example, the control device 60 determines the number of times to apply voltage as the quotient obtained by dividing the absolute value of the difference between the angle of the light emission direction and the target angle TA by 0.03. By applying voltage this number of times, the absolute value of the difference between the angle of the light emission direction and the target angle TA becomes less than the reference threshold value THB. Note that the method for calculating the number of times to apply voltage is not limited. After this step, the control device 60 disables the emission of low beams from the lamp unit 30 and ends control of the calibration.

[0136] Here, the flow returns to step S1 after step S3, and therefore may proceed to step S5 after step S3. That is, the control device 60 may perform the second control when the absolute value of the difference between the angle of the light emission direction and the target angle TA after the first control is equal to or greater than the reference threshold THB and less than the first threshold TH1. FIG. 15 is a timing chart schematically illustrating an example of the operation of the actuator 50 when the second control is performed after the first control in this embodiment. In the example shown in FIG. 15 , the absolute value of the difference between the angle of the light emission direction and the target angle TA is approximately 1.0 degrees, which is equal to or greater than the first threshold TH1, so the first control is performed. In this first control, a first voltage is applied to the motor 52 for a first period T1, and the angle of the light emission direction is brought closer to the target angle TA. The absolute value of the difference between the angle of the light emission direction and the target angle TA after the first control is approximately 0.1 degrees, which is equal to or greater than the reference threshold THB and less than the first threshold TH1, so the second control is performed. In the second control of this example, the voltage application VA in which the second voltage is applied to the motor 52 for the second period T2 is performed three times.

[0137] In this embodiment, when the voltage application VA is performed multiple times, the period T4 between the voltage applications VA is shorter than the second period T2, but longer than half the second period T2, i.e., approximately 90 ms. The second period T2 and the second voltage are the same for each voltage application VA. The period T5 between the end of the first control and the start of the second control is longer than the period T4 between the voltage applications VA in the second control, being at least twice the period T4.

[0138] In this way, in the calibration of the vehicle headlamp 1 of this embodiment, the acquisition of information on the angle of the emission direction of light and one of the first control and the second control are repeated until the absolute value of the difference between the angle of the emission direction of light emitted from the lighting unit 30 and the target angle TA becomes less than the reference threshold value THB.

[0139] As described above, the control device 60 of this embodiment as the fourth aspect is a control device for the actuator 50 that transmits the torque of the motor 52 to the lamp unit 30 and changes the orientation of the lamp unit 30 so that the light emission direction is tilted along a plane VP that is generally parallel to the vertical plane. The control device 60 performs the first control when the absolute value of the difference between the angle of the emission direction and the target angle TA is equal to or greater than the first threshold value TH1. The first threshold value TH1 is the absolute value of the amount of change in the angle of the emission direction when a first voltage is applied to the motor 52 for a period equal to or greater than the time constant τ of the motor 52. The first control controls the actuator 50 by applying the first voltage to the motor 52 for a first period T1 that is equal to or greater than the time constant τ so that the angle of the emission direction approaches the target angle TA. The control device 60 performs the second control when the absolute value of the difference between the angle of the emission direction and the target angle TA is equal to or greater than the reference threshold value THB and less than the first threshold value TH1. The reference threshold THB is the absolute value of the amount of change in the angle of the emission direction when the second voltage is applied to the motor 52 for a reference period shorter than the time constant τ. The second control is a control that controls the actuator 50 by applying the second voltage to the motor 52 for a second period T2, which is equal to or shorter than twice the reference period, one or more times until the absolute value of the difference between the angle of the emission direction and the target angle TA becomes less than the reference threshold THB.

[0140] Furthermore, a program according to the fifth aspect of the present embodiment is a program executed by a control device 60 of an actuator 50 that can transmit torque of a motor 52 to the lamp unit 30 to change the orientation of the lamp unit 30 so that the light emission direction is tilted along a plane VP that is generally parallel to the vertical plane. This program causes the control device 60 to execute a first control when the absolute value of the difference between the angle of the emission direction and a target angle TA is equal to or greater than a first threshold value TH1, and execute a second control when the absolute value of the difference between the angle of the emission direction and the target angle TA is equal to or greater than a reference threshold value THB and less than the first threshold value TH1. The first threshold value TH1 is the absolute value of the amount of change in the angle of the emission direction when a first voltage is applied to the motor 52 for a period equal to or greater than the time constant τ of the motor 52. The first control controls the actuator 50 by applying a first voltage to the motor 52 for a first period T1 that is equal to or greater than the time constant τ so that the angle of the emission direction approaches the target angle TA. The reference threshold THB is the absolute value of the amount of change in the angle of the emission direction when the second voltage is applied to the motor 52 for a reference period shorter than the time constant τ. The second control is a control that controls the actuator 50 by applying the second voltage to the motor 52 for a second period T2, which is equal to or shorter than twice the reference period, one or more times until the absolute value of the difference between the angle of the emission direction and the target angle TA becomes less than the reference threshold THB.

[0141] Furthermore, a vehicle headlamp 1 according to the present embodiment as a sixth aspect includes a lamp unit 30, an actuator 50, and a control device 60 that controls the actuator 50. The actuator 50 transmits torque from a motor 52 to the lamp unit 30 to change the orientation of the lamp unit 30 so that the light emission direction is tilted along a plane VP that is generally parallel to the vertical plane. The control device 60 performs a first control when the absolute value of the difference between the angle of the emission direction and a target angle TA is equal to or greater than a first threshold value TH1. The first threshold value TH1 is the absolute value of the amount of change in the angle of the emission direction when a first voltage is applied to the motor 52 for a period equal to or greater than the time constant τ of the motor 52. The first control controls the actuator 50 by applying the first voltage to the motor 52 for a first period T1 that is equal to or greater than the time constant τ so that the angle of the emission direction approaches the target angle TA. The control device 60 performs a second control when the absolute value of the difference between the angle of the emission direction and the target angle TA is equal to or greater than a reference threshold THB and less than a first threshold TH1. The reference threshold THB is the absolute value of the amount of change in the angle of the emission direction when a second voltage is applied to the motor 52 for a reference period shorter than the time constant τ. The second control is a control that controls the actuator 50 by performing a voltage application VA one or more times to apply the second voltage to the motor 52 for a second period T2, which is equal to or less than twice the reference period, until the absolute value of the difference between the angle of the emission direction and the target angle TA becomes less than the reference threshold THB.

[0142] In the control device 60, the program, and the vehicle headlight 1 according to the fourth to sixth aspects of the present embodiment, when the absolute value of the difference between the angle of the light emission direction and the target angle TA is equal to or greater than the reference threshold THB and less than the first threshold TH1, the voltage application VA is performed one or more times to apply the second voltage to the motor 52 for the second period T2 until the absolute value becomes less than the reference threshold THB. The reference threshold THB is the absolute value of the amount of change in the angle of the emission direction when the second voltage is applied to the motor 52 for a reference period shorter than the time constant τ, and the second period T2 is equal to or less than twice the reference period. Therefore, according to the control device 60, the program, and the vehicle headlight 1 according to the present embodiment, even when the absolute value of the difference between the angle of the emission direction and the target angle TA is equal to or greater than the reference threshold THB and less than the first threshold TH1, making it difficult to correct the deviation between the angle of the emission direction and the target angle TA, the angle of the emission direction can be made to approach the target angle TA. Therefore, the accuracy of adjusting the emission direction of the light emitted from the lighting unit 30 can be improved.

[0143] In the control device 60, the program, and the vehicle headlamp 1 of this embodiment, the second period T2 is equal to or shorter than the reference period. Therefore, the control device 60, the program, and the vehicle headlamp 1 of this embodiment reduce the amount of change in angle caused by a single voltage application VA, making it easier to bring the angle of the light emission direction closer to the target angle.

[0144] In the control device 60, program, and vehicle headlamp 1 of this embodiment, when the voltage application VA is performed multiple times in the second control, the period T4 between the voltage applications VA is shorter than the second period T2. Therefore, the control device 60, program, and vehicle headlamp 1 of this embodiment can prevent the time required to adjust the light emission direction from becoming longer. Note that the period T4 may be the same as the second period T2 or may be longer than the second period T2. When the period T4 is longer than the second period T2, it can be easier to measure the light emission direction between the voltage applications VA in the second control.

[0145] In the control device 60, program, and vehicle headlamp 1 of this embodiment, the second control is performed when the absolute value of the difference between the angle of the emission direction after the first control and the target angle TA is equal to or greater than the reference threshold THB and less than the first threshold TH1. When the voltage application VA is performed multiple times in this second control, the period T5 from the end of the first control to the start of the second control is longer than the period T4 between the voltage applications VA. Because the period during which the motor 52 rotates in the first control is longer than in the case of a single voltage application VA, the motor 52 tends to be in a rotating state due to inertial force immediately after the end of the first control. According to the control device 60, program, and vehicle headlamp 1 of this embodiment, the second control can be started while the motor 52 is stopped from rotating, thereby preventing a decrease in the accuracy of the adjustment of the light emission direction.

[0146] In the control device 60, program, and vehicle headlamp 1 of this embodiment, the second voltage is smaller than the first voltage. The control device 60, program, and vehicle headlamp 1 of this embodiment can reduce the amount of change in the orientation of the lamp unit 30 due to the applied voltage VA, making it easier to bring the angle of the light emission direction closer to the target angle TA. Note that the second voltage may be the same as the first voltage or may be greater than the first voltage.

[0147] In the control device 60, program, and vehicle headlamp 1 of this embodiment, when the first voltage is applied to the motor 52, the increase in the rotational speed of the motor 52 per unit time gradually increases and then gradually decreases to zero. Furthermore, the second period T2 is longer than the period T3 from when the first voltage is applied to the motor 52 until the increase in the rotational speed starts to decrease. Therefore, the control device 60, program, and vehicle headlamp 1 of this embodiment can prevent the orientation of the lamp unit 30 from becoming unchangeable due to the applied voltage VA. The second period T2 may be the same as or shorter than the period T3. Furthermore, the manner in which the increase in the rotational speed of the motor 52 per unit time changes when the first voltage is applied to the motor 52 is not limited. For example, the increase may gradually decrease to zero from the timing when the first voltage is applied.

[0148] Although the fourth to sixth aspects of the present invention have been described using the third embodiment as an example, the fourth to sixth aspects of the present invention are not limited to this.

[0149] For example, in the third embodiment, the actuator 50 is described as being capable of changing the orientation of the lamp unit 30 so that the light emission direction tilts along a plane VP generally parallel to the vertical plane. However, the actuator 50 may be configured to transmit the torque of the motor 52 to the lamp unit 30 and change the orientation of the lamp unit 30 so that the light emission direction tilts along a predetermined plane. For example, the configuration for transmitting the torque of the motor 52 to the lamp unit 30 is not limited. Furthermore, the predetermined plane is not limited to the plane VP generally parallel to the vertical plane. For example, the actuator 50 may be configured to change the orientation of the lamp unit 30 so that the light emission direction tilts along a plane generally parallel to the horizontal plane. Although not illustrated, an example of such an actuator 50 is a configuration including an output shaft extending in the vertical direction and having an upper end fixed to the lower side of the lamp unit 30. In this case, the torque of the motor 52 rotates the output shaft about its central axis. With this configuration, the direction of light emitted from the lighting unit 30 can be adjusted in the left-right direction along a plane that is roughly parallel to the horizontal plane.

[0150] Furthermore, in the third embodiment, when the voltage application VA is performed multiple times, the second period T2 and the second voltage are the same for each voltage application VA. However, the second period T2 and the second voltage are not limited. Below, Modifications 2 and 3, which are modifications of the third embodiment, are described. FIG. 16 is a timing chart schematically illustrating an example of the operation of the actuator 50 when the second control is performed after the first control in Modification 2. In the example shown in FIG. 16, when the voltage application VA is performed multiple times in the second control, the second period T2 of the voltage application VA performed later is shorter. According to this modification, the amount of change in the orientation of the lamp unit 30 during the voltage application VA can be made smaller for later voltage applications VA. Therefore, the closer the angle of the light emission direction to the target angle TA, the smaller the amount of change in the orientation of the lamp unit 30 can be, making it easier to bring the angle of the light emission direction closer to the target angle TA.

[0151] 17 is a timing chart schematically illustrating an example of the operation of the actuator 50 when the second control is performed after the first control in Modification 3. In the example shown in FIG. 17, when the voltage application VA is performed multiple times in the second control, the second voltage in the later voltage application VA is smaller. According to this modification, similar to Modification 2, the amount of change in the orientation of the lamp unit 30 in the voltage application VA can be made smaller the later the voltage application VA is performed. Therefore, the closer the angle of the light emission direction is to the target angle TA, the smaller the amount of change in the orientation of the lamp unit 30 can be made, making it easier to bring the angle of the light emission direction closer to the target angle TA.

[0152] When the voltage application VA is performed multiple times in the second control, the second voltage in the later voltage application VA may be smaller and the second period T2 in the later voltage application VA may be shorter. Also, the second voltage in the later voltage application VA may be higher and the second period T2 in the later voltage application VA may be longer.

[0153] In the third embodiment, the angle of the light emission direction is measured before the second control is performed, but this measurement is not performed during the second control. However, for example, if the voltage application VA is performed multiple times in the second control, the angle of the light emission direction may be measured each time the voltage application VA is performed, and at least one of the second voltage and the second period T2 in the next voltage application VA may be determined from the measured angle of the light emission direction. The above-mentioned Modifications 2 and 3 are particularly useful in such a configuration.

[0154] In the third embodiment, the weight of the lamp unit 30 generates torque in the lamp unit 30 such that the light emission direction changes downward. However, the direction of the torque generated in the lamp unit 30 by the weight of the lamp unit 30 is not limited. Furthermore, the position of the center of gravity 30G of the lamp unit 30 is not limited.

[0155] Furthermore, the flowchart of the operation of the control device 60 in the calibration of the vehicle headlamp 1 is not limited to this. For example, in the third embodiment, after step S5, the control device 60 stops the low beam emission from the lamp unit 30 and ends the control of the calibration. However, after step S5, the control device 60 may return the flow to step S1.

[0156] Furthermore, in the adjustment system SY of the third embodiment, the measuring device 110 receives light emitted from the lighting unit 30, measures the emission direction of the light from the lighting unit 30, and outputs a signal related to the emission direction of the light from the lighting unit 30 to the control device 60. However, the device for measuring the emission direction of the light from the lighting unit 30 is not limited to this. For example, if the emission direction of the light changes vertically as the lighting unit 30 tilts along a plane VP that is approximately parallel to the vertical plane as described above, the tilt angle of the lighting unit 30 in the vertical direction is also the angle of the emission direction of the light in the vertical direction. Therefore, for example, a sensor that tilts along the plane VP together with the lighting unit 30 and outputs a signal related to the tilt angle of the lighting unit 30 indirectly measures the angle of the emission direction of the light within the plane VP, and the signal output from the sensor is a signal related to the emission direction of the light. Therefore, such a sensor may output a signal related to the emission direction of the light to the control device 60. An example of such a sensor is a three-axis acceleration sensor attached to the lighting unit 30.

[0157] In the third embodiment, the vehicle lamp is described as a vehicle headlamp 1. However, the vehicle lamp is not limited to a vehicle headlamp, and may be, for example, a road surface drawing device that draws a predetermined image on a road surface by emitting light.

[0158] According to the first to sixth aspects of the present invention, a control device, a program, and a vehicle lamp are provided that can improve the accuracy of adjusting the emission direction of light emitted from a lighting unit, and can be used in fields such as vehicle lamps for automobiles, etc.

Claims

1. A control device that controls an actuator that transmits the torque of a motor to a lighting unit and can change the orientation of the lighting unit so that the light emission direction is tilted along a predetermined plane, and that is switchable between a calibration mode and a mode other than the calibration mode, and that includes a signal output unit and a power supply control unit, wherein in the calibration mode, when the absolute value of the difference between the angle of the emission direction and a target angle is less than a first threshold value that is the absolute value of the amount of change in the angle of the emission direction when a predetermined voltage is applied to the motor for a first period and is equal to or greater than a reference threshold value that is the absolute value of the amount of change in the angle of the emission direction when the predetermined voltage is applied to the motor for a reference period shorter than the first period, the signal output unit outputs a signal related to a specific direction from the angle of the emission direction toward the target angle to the power supply control unit for a second period that is less than twice the reference period, until the absolute value of the difference between the angle of the emission direction and the target angle becomes less than the reference threshold, the power supply control unit, when a signal relating to the specific direction is input, controls the actuator by applying the predetermined voltage to the motor for a period during which the signal is input so that the angle of the emission direction changes to the specific direction; and during at least a portion of a period of a mode other than the calibration mode, when an absolute value of a difference between the angle of the emission direction and the target angle is less than the first threshold value and a signal relating to the specific direction is input, the power supply control unit does not apply voltage to the motor.

2. The control device described in claim 1, characterized in that the signal relating to the specific direction is a signal indicating a specific angle where the absolute value of the difference between the target angle on the angle side of the emission direction and the target angle on the opposite side is greater than or equal to the first threshold value.

3. The control device described in claim 1, characterized in that the signal related to the specific direction is a signal indicating a value obtained by subtracting the angle of the emission direction from a specific angle at which the absolute value of the difference between the target angle on the angle side of the emission direction and the target angle on the opposite side is equal to or greater than the first threshold value.

4. The control device described in claim 1, characterized in that during the entire period of the modes other than the calibration mode, the power supply control unit does not apply voltage to the motor when the absolute value of the difference between the angle of the emission direction and the target angle is less than the first threshold value and a signal related to the specific direction is input.

5. The control device described in claim 1, characterized in that in at least one of the calibration mode and the mode other than the calibration mode, the power supply control unit does not apply voltage to the motor when the absolute value of the difference between the target angle and one of the two ends of the angular range of the emission direction that can be changed by the actuator is equal to or less than a second threshold that is equal to or greater than the first threshold.

6. A program executed by a control device including a signal output unit and a power supply control unit, which controls an actuator that can change the orientation of a lighting unit by transmitting the torque of a motor to the lighting unit so that the light emission direction is tilted along a predetermined plane, and which is switchable between a calibration mode and a mode other than the calibration mode, wherein in the calibration mode, the program causes the signal output unit to execute a step of outputting a signal relating to a specific direction from the light emission direction angle towards the target angle to the power supply control unit for a second period that is less than twice the reference period, when the absolute value of the difference between the light emission direction angle and the target angle is less than a first threshold that is the absolute value of the amount of change in the light emission direction angle when a predetermined voltage is applied to the motor for a first period and is equal to or greater than a reference threshold that is the absolute value of the amount of change in the light emission direction angle when the predetermined voltage is applied to the motor for a reference period that is shorter than the first period, one or more times; a step of controlling the actuator by applying the predetermined voltage to the motor for a period during which the signal is input so that the angle of the emission direction changes to the specific direction when the signal related to the specific direction is input to the power supply control unit, and a step of not applying voltage to the motor when the absolute value of the difference between the angle of the emission direction and the target angle is less than the first threshold and the signal related to the specific direction is input during at least a portion of the period of the mode other than the calibration mode.

7. A device comprising: an actuator capable of transmitting motor torque to a lamp unit to change the orientation of the lamp unit so that the light emission direction is tilted along a predetermined plane; and a control device that controls the actuator and is switchable between a calibration mode and a mode other than the calibration mode, and includes a signal output unit and a power supply control unit, wherein in the calibration mode, when the absolute value of the difference between the angle of the emission direction and the target angle is less than a first threshold value which is the absolute value of the amount of change in the angle of the emission direction when a predetermined voltage is applied to the motor for a first period and is equal to or greater than a reference threshold value which is the absolute value of the amount of change in the angle of the emission direction when the predetermined voltage is applied to the motor for a reference period shorter than the first period, the signal output unit outputs a signal relating to a specific direction from the angle of the emission direction towards the target angle to the power supply control unit for a second period which is less than twice the reference period, until the absolute value of the difference between the angle of the emission direction and the target angle becomes less than the reference threshold, When a signal related to the specific direction is input, the power supply control unit controls the actuator by applying the predetermined voltage to the motor for a period during which the signal is input so that the angle of the emission direction changes to the specific direction, and during at least a portion of a period of a mode other than the calibration mode, the power supply control unit does not apply voltage to the motor when an absolute value of a difference between the angle of the emission direction and the target angle is less than the first threshold value and a signal related to the specific direction is input.

8. A control device for an actuator that can change the orientation of a lighting unit by transmitting motor torque to the lighting unit so that the light emission direction is tilted along a predetermined plane, characterized in that, when the absolute value of the difference between the angle of the emission direction and a target angle is equal to or greater than a first threshold which is the absolute value of the amount of change in the angle of the emission direction when a first voltage is applied to the motor for a period of the motor's time constant, a first control is performed to control the actuator by applying the first voltage to the motor for a first period of time equal to or greater than the time constant so that the angle of the emission direction approaches the target angle, and when the absolute value of the difference between the angle of the emission direction and the target angle is equal to or greater than a reference threshold which is the absolute value of the amount of change in the angle of the emission direction when a second voltage is applied to the motor for a reference period shorter than the time constant but less than the first threshold, a second control is performed to control the actuator by applying the second voltage to the motor for a second period of time which is equal to or less than twice the reference period one or more times until the absolute value of the difference between the angle of the emission direction and the target angle becomes less than the reference threshold.

9. The control device according to claim 8, wherein the second period is equal to or less than the reference period.

10. The control device according to claim 8, wherein the voltage application is performed multiple times in the second control.

11. The control device of claim 10, wherein the period between voltage applications is longer than the second period.

12. The control device of claim 10, wherein the period between voltage applications is shorter than the second period.

13. The control device according to claim 10, wherein the second period in the voltage application performed later is shorter.

14. The control device according to claim 10, wherein the second voltage applied later is smaller.

15. The control device described in claim 8, characterized in that if the absolute value of the difference between the angle of the emission direction and the target angle after the first control is equal to or greater than the reference threshold and less than the first threshold, the second control is performed, and if the voltage application is performed multiple times in the second control, the period from the end of the first control to the start of the second control is longer than the period between the voltage applications.

16. The control device of claim 8, wherein the second voltage is less than the first voltage.

17. A control device as described in claim 8, characterized in that when the first voltage is applied to the motor, the increase in the rotational speed of the motor per unit time gradually increases and then gradually decreases to zero, and the second period is longer than the period from when the first voltage is applied to the motor to when the increase begins to decrease.

18. The control device according to claim 8, wherein a signal relating to the angle of the emission direction is input from a measuring device that receives light emitted from the lighting unit and measures the emission direction.

19. A program executed by a control device of an actuator capable of transmitting torque of a motor to a lighting unit and changing the orientation of the lighting unit so that the light emission direction is tilted along a predetermined plane, the program comprising: a program causing the program to execute a step of: performing a first control to control the actuator by applying the first voltage to the motor for a first period that is equal to or greater than the time constant, when an absolute value of a difference between the angle of the emission direction and a target angle is equal to or greater than a first threshold that is an absolute value of an amount of change in the angle of the emission direction when a first voltage is applied to the motor for a period that is equal to a time constant of the motor; and performing a second control to control the actuator by applying the second voltage to the motor for a second period that is equal to or less than twice the reference period, one or more times, until the absolute value of the difference between the angle of the emission direction and the target angle becomes less than the reference threshold, when the absolute value of the difference between the angle of the emission direction and the target angle is equal to or greater than a reference threshold that is an absolute value of an amount of change in the angle of the emission direction when a second voltage is applied to the motor for a reference period that is shorter than the time constant, but less than the first threshold.

20. A lighting device comprising: a lighting unit; an actuator that can change the orientation of the lighting unit by transmitting torque of a motor to the lighting unit so that the direction of light emission is tilted along a predetermined plane; and a control device that controls the actuator, the control device performs a first control of controlling the actuator by applying the first voltage to the motor for a first period equal to or greater than the time constant so that the angle of the emission direction approaches the target angle, when the absolute value of the difference between the angle of the emission direction and the target angle is equal to or greater than a first threshold which is an absolute value of an amount of change in the angle of the emission direction when a first voltage is applied to the motor for a period equal to a time constant of the motor; and performs a second control of controlling the actuator by applying the second voltage to the motor for a second period equal to or less than twice the reference period one or more times until the absolute value of the difference between the angle of the emission direction and the target angle becomes less than the reference threshold, when the absolute value of the difference between the angle of the emission direction and the target angle is equal to or greater than a reference threshold which is an absolute value of an amount of change in the angle of the emission direction when a second voltage is applied to the motor for a reference period shorter than the time constant but less than the first threshold.

Images