Vehicle headlight

Abstract

This vehicle headlight comprises a cut-off line (CL), a first optical unit (70) that emits light at an area including at least an area below the cut-off line (CL), a second optical unit (80) that can emit light at an area including at least an area above the cut-off line (CL) and can dim any area within that area, and a third optical unit (90) that emits light so as to overlap with at least a portion of the cut-off line (CL). The third optical unit (90) has a plurality of light sources, the lighting states of which can be changed independently of one another. During high-beam lighting, the first optical unit (70), the second optical unit (80), and a subset of the plurality of light sources of the third optical unit (90) are lit, and another subset of the plurality of light sources of the third optical unit (90) are lit at a reduced intensity. During low-beam lighting, the first optical unit (70) and all of the plurality of light sources of the third optical unit (90) are lit. During high-beam lighting, at least a portion of normal power, which is consumed when the subset of other light sources to be lit at a reduced intensity among the plurality of light sources of the third optical unit (90) are lit without being reduced in intensity, is supplied to the subset light sources to be lit.

Description

Vehicle headlamp

[0001] The present disclosure relates to a vehicle headlamp.

[0002] There is known a vehicle headlamp that irradiates an ADB (Adaptive Driving Beam) light distribution pattern. In Patent Document 1, in order to reduce the discomfort of the vehicle occupants, when the left - right width of the light - shielding area of the ADB light distribution pattern is relatively wide, it suppresses the excessive brightening of the ends of the light - shielding area, and when the left - right width of the light - shielding area is relatively narrow, it increases the light intensity at the ends of the light - shielding area to emphasize the ends and ensure the brightness around the light - shielding area.

[0003] Japanese Patent Application Laid - Open No. 2018 - 172038

[0004] By the way, from the viewpoint of not dazzling oncoming vehicles, etc., the cut - off line of the low - beam light distribution pattern is preferably distinct between light and dark. On the other hand, when the driver wants to see a dark area in the distance, if the contrast ratio between light and dark is too large, the dark area becomes difficult to see, so a cut - off line with a gentle gradient between light and dark is preferable.

[0005] In order to form such a cut - off line with a large contrast ratio between light and dark and a cut - off line with a small contrast ratio between light and dark, in addition to an optical unit that irradiates light to form a low - beam light distribution pattern, it is conceivable to provide an additional optical unit that irradiates light so as to overlap at least a part of the cut - off line. By turning on and off the additional optical unit, it is possible to switch between a cut - off line with a large contrast ratio between light and dark and a cut - off line with a small contrast ratio between light and dark. However, when the additional optical unit is turned off, since light cannot be irradiated for that portion, there is room for further improvement as a light distribution pattern with good visibility.

[0006] Therefore, an object of the present disclosure is to provide a vehicle headlamp that forms a light distribution pattern with better visibility.

[0007] A vehicle headlight according to one aspect of the present disclosure is a vehicle headlight installed on a vehicle, comprising: a cutoff line; a first optical unit that irradiates light to a region including at least a region below the cutoff line; a second optical unit that can irradiate light to a region including at least a region above the cutoff line and can dim any region therein; and a third optical unit that irradiates light so as to overlap at least a portion of the cutoff line, wherein the third optical unit has a plurality of light sources whose lighting state can be changed independently of each other, and when the high beam is on, the first optical unit, the second optical unit, and some of the plurality of light sources of the third optical unit are lit, and some of the other plurality of light sources of the third optical unit are lit with dimming enabled, and when the low beam is on, all of the plurality of light sources of the first optical unit and the third optical unit are lit, and when the high beam is on, at least a portion of the normal power that would be generated if the other plurality of light sources of the third optical unit that are dimmed were lit is supplied to the lit light sources.

[0008] According to this disclosure, when the low beam is illuminated, the third optical unit irradiates light so as to overlap with the cutoff line formed by the first optical unit. As a result, a low beam light distribution pattern is formed that is blurred and has good visibility compared to the cutoff line formed by the first optical unit alone.

[0009] On the other hand, when the high beams are on, a so-called ADB (Adaptive Deposition) light distribution pattern is projected, forming a distinct cutoff line. However, since the cutoff line only appears in the dimmed area, it does not significantly worsen visibility.

[0010] Furthermore, according to this disclosure, when the high beams are on, at least a portion of the normal power that would be generated if some of the light sources of the third optical unit were illuminated without dimming is supplied to some of the light sources that remain illuminated. When some of the light sources of the multiple light sources are dimmed, at least a portion of the normal power that would be generated if those other light sources were illuminated without dimming can be utilized to increase the power supplied to the light sources that remain illuminated. As a result, the third optical unit can reduce glare to oncoming vehicles by illuminating some of the other light sources while supplying more power to some of the light sources, thereby brightening at least a portion of the cutoff line and further improving the visibility of the light distribution pattern.

[0011] A vehicle headlight according to another aspect of the present disclosure is a vehicle headlight installed on a vehicle, comprising: a cutoff line; a first optical unit that irradiates light to a region including at least a region below the cutoff line; a second optical unit that can irradiate light to a region including at least a region above the cutoff line and can dim any region thereof; and a third optical unit that irradiates light so as to overlap at least a portion of the cutoff line, wherein when the high beam is on, the first optical unit and the second optical unit are lit, and at least a portion of the power when the third optical unit is lit is supplied to at least one of the first optical unit and the second optical unit; and when the low beam is on, the first optical unit and the third optical unit are lit.

[0012] According to this disclosure, when the low beam is illuminated, the third optical unit irradiates light so as to overlap with the cutoff line formed by the first optical unit. As a result, a low beam light distribution pattern is formed that is blurred and has good visibility compared to the cutoff line formed by the first optical unit alone.

[0013] On the other hand, when the high beams are on, a so-called ADB (Adaptive Deposition) light distribution pattern is projected, forming a distinct cutoff line. However, since the cutoff line only appears in the dimmed area, it does not significantly worsen visibility.

[0014] Furthermore, according to this disclosure, when the high beam is on, at least a portion of the power that would be generated if the third optical unit were lit is supplied to at least one of the first optical unit and the second optical unit. In other words, when the third optical unit is turned off, at least a portion of the power that would be generated if the third optical unit were lit can be used to increase the power supplied to at least one of the first and second optical units. As a result, at least one of the regions below the cutoff line and the region above the cutoff line can be brightened, thereby further improving the visibility of the light distribution pattern.

[0015] According to this disclosure, a vehicle headlight is provided that forms a light distribution pattern with better visibility.

[0016] Figure 1 is a block diagram of the vehicle system configuration, including the vehicle headlight. Figure 2 is a cross-sectional view of the vehicle headlight. Figure 3 is a diagram illustrating the various light distribution patterns emitted by the vehicle headlight. Figure 4 is a diagram illustrating the low beam light distribution pattern when the low beam is on. Figure 5 is a diagram illustrating the high beam light distribution pattern when the high beam is on, for a vehicle headlight according to a comparative example. Figure 6 is a diagram illustrating the high beam light distribution pattern when the high beam is on, for a vehicle headlight according to the first embodiment. Figure 7 is a diagram illustrating the high beam light distribution pattern when the high beam is on, for a vehicle headlight according to the second embodiment. Figure 8 is a flowchart illustrating the processing of a vehicle headlight according to Modification Example 1. Figure 9 is a flowchart illustrating the processing of a vehicle headlight according to Modification Example 2. Figure 10 is a diagram illustrating the various light distribution patterns emitted by the vehicle headlight according to the third embodiment. Figure 11 is a diagram illustrating the low beam light distribution pattern when the low beam is on, for a vehicle headlight according to the third embodiment. Figure 12 illustrates the high beam light distribution pattern of a vehicle headlight according to a comparative example when the high beams are on. Figure 13 illustrates the high beam light distribution pattern of a vehicle headlight according to the third embodiment when the high beams are on. Figure 14 illustrates the high beam light distribution pattern of a vehicle headlight according to the fourth embodiment when the high beams are on.

[0017] The embodiments of this disclosure will be described below with reference to the drawings. For the sake of clarity, the description of components having the same reference numeral as those already described in the description of the embodiments will be omitted. Furthermore, the dimensions of the components shown in these drawings may differ from the actual dimensions of the components for the sake of clarity.

[0018] Furthermore, in this disclosure, for the sake of explanation, the terms "left-right direction," "up-down direction," and "front-back direction" may be referred to as appropriate. These directions are relative directions set for the vehicle headlight 10 exemplified in Figure 2. Here, the "left-right direction" includes the "left direction" and the "right direction," as well as the vehicle width direction of the vehicle on which the vehicle headlight 10 is mounted. The "up-down direction" includes the "up direction" and the "down direction." The "front-back direction" is the front-back direction of the vehicle, and includes the "forward direction" and the "rear direction." The front-back direction is perpendicular to the left-right direction and the up-down direction. In each figure, the symbol U indicates the upward direction. The symbol D indicates the downward direction. The symbol F indicates the forward direction. The symbol B indicates the rear direction. The symbol L indicates the left direction. The symbol R indicates the right direction. The left-right direction is an example of the horizontal direction.

[0019] The vehicle headlight 10 according to this disclosure will be described with reference to Figures 1 to 5. The vehicle headlight 10 is mounted on the front right and front left sides of the vehicle 1, respectively. The vehicle headlight 10 is configured to form a high beam light distribution pattern PH and a low beam light distribution pattern PL.

[0020] Figure 1 is a block diagram of the system configuration of vehicle 1, including the vehicle headlight 10. As illustrated in Figure 1, vehicle 1 comprises the vehicle headlight 10, a camera 30, a light switch 40, and a vehicle control unit 50.

[0021] The vehicle headlight 10 comprises a lamp control unit 60, a first optical unit 70, a second optical unit 80, and a third optical unit 90. Details of the vehicle headlight 10 will be described later.

[0022] Camera 30 is positioned near the windshield of vehicle 1. Camera 30 is a camera that includes an image sensor such as a CCD (Charge-Coupled Device) or CMOS (Complementary MOS). Camera 30 acquires image data by imaging the area around vehicle 1 (for example, in front of vehicle 1). Camera 30 outputs the image data to vehicle control unit 50.

[0023] The light switch 40 is located near the steering mechanism of the vehicle 1. The light switch 40 is configured to switch the vehicle headlights 10 ON / OFF or to switch the light distribution pattern in response to an operation by the driver of the vehicle 1. When the driver of the vehicle 1 operates the light switch 40, the light switch 40 generates a control signal to illuminate with a light distribution pattern corresponding to the operation and transmits the signal to the vehicle control unit 50.

[0024] The vehicle control unit 50 is configured to control the driving of the vehicle 1. The vehicle control unit 50 is configured to determine the surrounding environment of the vehicle 1 based on surrounding environment information and to transmit the determination result to the lamp control unit 60 of the vehicle headlight 10. The vehicle control unit 50 is composed of, for example, at least one electronic control unit (ECU). The electronic control unit includes, for example, a computer system including one or more processors and one or more memories, and an electronic circuit composed of active elements such as transistors and passive elements.

[0025] The vehicle control unit 50 is configured to perform image analysis on the image data output from the camera 30. The vehicle control unit 50 generates ambient environment information indicating the surrounding environment of the vehicle 1 from the image data and transmits this ambient environment information to the lamp control unit 60 of the vehicle headlight 10. The ambient environment information includes, for example, positional information of objects located in front of the vehicle 1 (oncoming vehicles, vehicles ahead, signs, etc.).

[0026] The vehicle control unit 50 transmits a signal to the lamp control unit 60 of the vehicle headlight 10 to control the vehicle headlight 10 based on the control signal from the light switch 40.

[0027] The lamp control unit 60 of the vehicle headlight 10 may have the same hardware configuration as the vehicle control unit 50. The lamp control unit 60 is configured to control the first optical unit 70, the second optical unit 80, and the third optical unit 90 based on surrounding environment information received from the vehicle control unit 50.

[0028] Next, the details of the vehicle headlight 10 will be described. Figure 2 is a cross-sectional view of the vehicle headlight 10. As illustrated in Figure 2, the vehicle headlight 10 comprises a lamp body 11 having an opening in front of the vehicle headlight 10, and a translucent outer cover 12 that covers the opening of the lamp body 11. A lamp control unit 60, a first optical unit 70, a second optical unit 80, and a third optical unit 90 are housed in the lamp chamber 13 formed by the lamp body 11 and the outer cover 12.

[0029] The first optical unit 70 is configured to illuminate a region including the cutoff line and at least the region below the cutoff line. Details of the light distribution pattern illuminated by the first optical unit 70 will be described later.

[0030] The first optical unit 70 includes, for example, a plurality of light sources 71, a reflector 72, and a projection lens 73. The light sources 71 may be composed of, for example, LED (Light Emitting Diode) elements or LD (Laser Diode) elements. The light sources 71 are configured to emit light toward the reflector 72. The reflector 72 is configured to reflect the light emitted from the light sources 71 toward the projection lens 73. The projection lens 73 is, for example, an aspherical lens whose front surface is convex and its rear surface is flat. The projection lens 73 is configured to project the light reflected by the reflector 72 into the front area of ​​the vehicle 1.

[0031] The second optical unit 80 is configured to illuminate a region including at least a region above the cutoff line. Furthermore, the second optical unit 80 can attenuate any region within the region above the cutoff line. In this specification, the term "attenuating" includes blocking at least a portion of the light emitted from one optical unit and reducing the intensity of the light emitted from one optical unit.

[0032] The second optical unit 80 can, for example, emit an ADB (Adaptive Driving Beam) light distribution pattern. The ADB light distribution pattern is a high beam light distribution pattern PH that does not emit light to areas where objects that block light, such as preceding vehicles or oncoming vehicles, exist. It is a light distribution pattern that changes the non-illuminated area depending on the presence and location of such objects.

[0033] The second optical unit 80 includes a light source 81 and a projection lens 82. The light source 81 may be composed of, for example, a plurality of micro-LED light-emitting elements. The lighting state of the plurality of micro-LED light-emitting elements included in the light source 81 can be changed independently of each other. In other words, in the vehicle headlight 10, the lamp control unit 60 can perform ON / OFF control and brightness adjustment for each of the micro-LED light-emitting elements included in the light source 81. The projection lens 82 may have a configuration similar to that of the projection lens 73, for example.

[0034] The third optical unit 90 is configured to emit light so as to overlap with at least a portion of the cutoff line. The third optical unit 90 includes, for example, a light source composed of an LED array. An LED array is, for example, a light source in which multiple LED elements are arranged in an array. The illumination state of the multiple LED elements included in the third optical unit 90 can be changed independently of each other. In this case, the vehicle headlight 10 can perform ON / OFF control and brightness adjustment for each of the micro-LED elements included in the third optical unit 90 using the lamp control unit 60.

[0035] Next, with reference to Figure 3, the first light distribution pattern P11 emitted from the first optical unit 70, the second light distribution pattern P12 emitted from the second optical unit 80, and the third light distribution pattern P13 emitted from the third optical unit 90 will be described. Figure 3 is a diagram illustrating each light distribution pattern emitted by the vehicle headlight 10. In this disclosure, the case where the vehicle 1 is traveling in the right lane will be described. The first light distribution pattern P11, the second light distribution pattern P12, and the third light distribution pattern P13 illustrated in Figure 3 are shown projected onto a virtual vertical screen at a predetermined position in front of the vehicle 1 (for example, 25 m in front of the vehicle 1). The light distribution patterns illustrated in the following figures are also shown projected onto a virtual vertical screen at a predetermined position in front of the vehicle 1. Furthermore, Figure 3 shows a V-V line indicating the vertical direction (up and down direction in Figure 3) at the center of the illumination range of the vehicle headlight 10, and an H-H line perpendicular to the V-V line and extending horizontally (left and right direction in Figure 3). Similarly, subsequent diagrams illustrating light distribution patterns also show a V-V line indicating the vertical direction at the center of the illumination range of the vehicle headlight 10, and an H-H line perpendicular to the V-V line and extending horizontally.

[0036] As illustrated in Figure 3, the first light distribution pattern P11 has a cutoff line CL. The first light distribution pattern P11 is irradiated by the first optical unit 70 onto the area including the cutoff line CL and the area below the cutoff line CL (the area with downward sloping hatching in Figure 3).

[0037] The second light distribution pattern P12, together with the first light distribution pattern P11, forms a so-called high-beam light distribution pattern PH. The second light distribution pattern P12 is irradiated by the second optical unit 80 to a region that includes at least the area above the cutoff line CL (the area with upward-sloping diagonal hatching in Figure 3). In this disclosure, the second optical unit 80 irradiates the ADB light distribution pattern. Therefore, any region in the second light distribution pattern P12 may be attenuated.

[0038] The third light distribution pattern P13 is irradiated by the third optical unit 90 so as to overlap with at least a portion of the cutoff line CL of the first light distribution pattern P11 (the portion with vertical hatching in Figure 3). In this disclosure, the third light distribution pattern P13 together with the first light distribution pattern P11 forms the low beam light distribution pattern PL.

[0039] Next, with reference to Figures 4 and 5, the low-beam light distribution pattern PL emitted from the vehicle headlight 10 when the low beam is on, and the high-beam light distribution pattern PH emitted from the vehicle headlight 10 when the high beam is on will be explained, respectively. When the low beam is on, it refers to the time when the driver of vehicle 1 performs an operation on the light switch 40 to emit the low-beam light distribution pattern PL. When the high beam is on, it refers to the time when the driver of vehicle 1 performs an operation on the light switch 40 to emit the high-beam light distribution pattern PH. Figure 4 is a diagram illustrating the low-beam light distribution pattern PL when the low beam is on. Figure 5 is a diagram illustrating the high-beam light distribution pattern PH when the high beam is on in a vehicle headlight 10Z according to a comparative example. The high-beam light distribution pattern PH emitted in this disclosure is an ADB light distribution pattern.

[0040] As illustrated in Figure 4, when the low beam is on, the vehicle headlight 10 illuminates a low beam light distribution pattern PL consisting of a first light distribution pattern P11 and a third light distribution pattern P13 by lighting up all of the multiple LED elements of the first optical unit 70 and the third optical unit 90. That is, the low beam light distribution pattern PL in this disclosure includes the third light distribution pattern P13, and the third light distribution pattern P13 is illuminated so as to overlap with the cutoff line CL. Therefore, the area illuminated by the overlapping first light distribution pattern P11 and the third light distribution pattern P13 is brighter than the area illuminated only by the first light distribution pattern P11 and not by the third light distribution pattern P13. Thus, the cutoff line of the light distribution pattern PL when the low beam is selected changes in brightness in two stages. If we count from the area where no light is illuminated, it can also be said that the cutoff line of the light distribution pattern PL when the low beam is selected changes in brightness in three stages.

[0041] As illustrated in Figure 5, when the high beams are on, the vehicle headlight 10 illuminates some of the LED elements of the first optical unit 70, the second optical unit 80, and the third optical unit 90. On the other hand, the vehicle headlight 10 turns off some of the other light sources of the LED elements of the third optical unit 90. As a result, the vehicle headlight 10 illuminates with a high beam light distribution pattern PH consisting of a first light distribution pattern P11, a second light distribution pattern P12, and a third light distribution pattern P13.

[0042] In the example shown in Figure 5, since there is a preceding vehicle 1B in front of vehicle 1, camera 30 outputs imaging data related to the preceding vehicle 1B to vehicle control unit 50. The vehicle control unit 50 generates surrounding environment information, including the position information of the preceding vehicle 1B, from the imaging data output from camera 30, and transmits this surrounding environment information to lamp control unit 60. Based on the surrounding environment information received from vehicle control unit 50, lamp control unit 60 controls the second optical unit 80 and the third optical unit 90 so that light is not emitted toward the preceding vehicle 1B. Specifically, among the multiple micro-LED light-emitting elements of the second optical unit 80, the micro-LED elements that emit light toward the preceding vehicle 1B are turned off, and the other micro-LED elements are turned on. Similarly, among the multiple LED elements of the third optical unit 90, the LED elements that emit light toward the preceding vehicle 1B are turned off, and the other LED elements are turned on. For this reason, in the example shown in Figure 5, the area around the preceding vehicle 1B is shielded from light. Therefore, when the high beams are on, light does not illuminate a portion of the second light distribution pattern P12 that includes the preceding vehicle 1B, and a portion of the third light distribution pattern P13 that includes the preceding vehicle 1B. Since the area surrounding the preceding vehicle 1B is shielded from light, the portion C11 of the cutoff line CL located below the preceding vehicle 1B shows a clear difference in brightness. In other words, the cutoff line CL is formed by the area illuminated by the first light distribution pattern P11 and the area not illuminated by the first light distribution pattern P11, and the brightness does not change in two steps near the cutoff line CL. Counting from the area not illuminated, the cutoff line of the high beam light distribution pattern PH only changes in brightness in two steps. For this reason, the cutoff run CL formed when the low beam light distribution pattern PL is illuminated appears blurred compared to at least a portion (in this disclosure, portion C11) of the cutoff line CL formed when the high beam light distribution pattern PH (ADB light distribution pattern) is illuminated. Furthermore, since typical low-beam light distribution patterns are formed by blocking some of the light, the difference in brightness at the cutoff line is usually clear. The cutoff line of a typical low-beam light distribution pattern does not change in brightness in two stages.Therefore, the cut-off line of the low-beam light distribution pattern PL of the present disclosure is blurred compared to the cut-off line of a general low-beam light distribution pattern.

[0043] In this way, by turning on and off a plurality of LED elements of the third optical unit 90, it is possible to switch between a cut-off line with a large contrast ratio between light and darkness and a cut-off line with a small contrast ratio between light and darkness. Also, when some other LED elements of the plurality of LED elements of the third optical unit 90 are dimmed and lit, light cannot be irradiated in front of the vehicle 1 compared to the case where all the plurality of LED elements of the third optical unit 90 are lit.

[0044] Thus, when some other LED elements of the third optical unit 90 are dimmed and lit, it is conceivable to utilize the power when the said some other LED elements are lit without being dimmed. When the vehicle headlamp 10 of the present disclosure is in high-beam lighting, some of the plurality of LED elements of the first optical unit 70, the second optical unit 80, and the third optical unit 90 are lit without being dimmed, and some other LED elements of the plurality of LED elements of the third optical unit 90 are dimmed and lit. Further, at least a part of the power when the LED elements to be dimmed are lit without being dimmed is supplied to the LED elements to be lit. Hereinafter, the first embodiment and the second embodiment will be described.

[0045] (First Embodiment) Referring to FIGS. 3, FIG. 4, and FIG. 6, the vehicle headlamp 10 according to the first embodiment will be described. The third optical unit 90 has, for example, 12 LED elements. These plurality of LED elements are provided in parallel in the left-right direction. The plurality of LED elements are all the same LED elements. The plurality of LED elements are configured to change their lighting states independently of each other. Each of the plurality of LED elements irradiates light so as to overlap a part of the cut-off line CL. Each of the 12 LED elements irradiates light to a corresponding irradiation region to irradiate a sub-third light distribution pattern. As a result, the third light distribution pattern P13 irradiated from the third optical unit 90 is divided into 12 parts (see FIGS. 3 and FIG. 4).

[0046] The sub-third light distribution pattern P13A is located at the leftmost of the third light distribution pattern P13. The sub-third light distribution pattern P13B is located to the immediate right of the sub-third light distribution pattern P13A. The sub-third light distribution pattern P13C is located to the immediate right of the sub-third light distribution pattern P13B. The sub-third light distribution pattern P13D is located to the immediate right of the sub-third light distribution pattern P13C. The sub-third light distribution pattern P13E is located to the immediate right of the sub-third light distribution pattern P13D. The sub-third light distribution pattern P13F is located to the immediate right of the sub-third light distribution pattern P13E. The sub-third light distribution pattern P13G is located to the immediate right of the sub-third light distribution pattern P13F. The sub-third light distribution pattern P13H is located to the immediate right of the sub-third light distribution pattern P13G. The sub-third light distribution pattern P13I is located to the immediate right of the sub-third light distribution pattern P13H. The sub-third light distribution pattern P13J is located to the immediate right of the sub-third light distribution pattern P13I. The sub-third light distribution pattern P13K is located to the immediate right of the sub-third light distribution pattern P13J. The sub-third light distribution pattern P13L is located to the immediate right of the sub-third light distribution pattern P13K and at the rightmost of the third light distribution pattern P13.

[0047] In the vehicle headlamp 10 of the present embodiment, assume that the voltage values applied to the plurality of LED elements of the third optical unit 90 are a predetermined common constant value. In the present embodiment, the "common constant value" includes not only the case where the values are exactly the same, but also the case where the difference between the two is sufficiently small and they are evaluated as substantially the same value. Also, assume that the current values applied to the plurality of LED elements of the third optical unit 90 are variable.

[0048] In the third optical unit 90, the power supplied to one LED element is obtained by multiplying the voltage value applied to the one LED element by the current value applied to the LED element. For example, when there are 3 dimming LED elements, the amount of electric power obtained by multiplying a certain voltage value by the current value for lighting the 3 LED elements without dimming is the normal power when some other light sources that dim are lit without dimming.

[0049] In this embodiment, for the sake of brevity, an example of dimming will be described in which some of the LED elements of the third optical unit 90 are turned off. When the high beams are on and there is a vehicle ahead that will block the light, such as the preceding vehicle 1B, the multiple LED elements of the third optical unit 90 include multiple LED elements that remain lit without dimming, and at least one LED element that remains off. In this case, the normal power, which is the amount of energy obtained by multiplying a certain voltage value by the current value that allows the off-light LED element to light up without dimming, can be used for other purposes. In this embodiment, the normal power, which is the amount of energy when the off-light LED element is lit without dimming, is supplied equally to the lit LED elements. The lit LED elements are an example of a lit light source. The off-light LED elements are an example of other some light sources that dim, and are an example of a dimming light source.

[0050] Figure 6 illustrates the high-beam light distribution pattern PH1 of the vehicle headlight 10 according to the first embodiment when the high beam is on. In Figure 6, compared to the light distribution pattern illustrated in Figure 3, the illuminated area that is brightly lit by the vehicle headlight 10 is shown with darker hatching.

[0051] As illustrated in Figure 6, in this embodiment, the preceding vehicle 1B is located in the area in front of vehicle 1 that corresponds to sub-third light distribution pattern P13H, sub-third light distribution pattern P13I, and sub-third light distribution pattern P13J. In this case, the nine illuminated LED elements are lit, and sub-third light distribution patterns P13A to P13G, sub-third light distribution pattern P13K, and sub-third light distribution pattern P13L are illuminated. On the other hand, the three unlit LED elements are turned off, and no light is emitted to sub-third light distribution patterns P13H, P13I, and P13J. The normal power supplied when the three unlit LED elements are lit without dimming is supplied equally to the nine illuminated LED elements.

[0052] Here, the voltage applied to the multiple LED elements of the third optical unit 90 is constant, and all of the multiple LED elements are the same LED element. The current value when one lit LED element illuminating the sub-third light distribution pattern P13A is lit without dimming is defined as 1. If the normal power when three unlit LED elements are lit without dimming is supplied equally to the nine lit LED elements, the current applied to one lit LED element will be approximately 1.3. Since the voltage value is constant, as the current supplied to one LED element increases, the power also increases. The more power supplied, the more light is emitted from one lit LED element, and the brighter the sub-third light distribution pattern P13A becomes. Similarly, the sub-third light distribution patterns P13B through P13G, the sub-third light distribution pattern P13K, and the sub-third light distribution pattern P13L also become brighter. Furthermore, all of the normal power that would be supplied to the illuminated LED element if the unlit LED element were lit without dimming may be supplied to the illuminated LED element, or only a portion of the normal power that would be supplied to the illuminated LED element if the unlit LED element were lit without dimming may be supplied to the illuminated LED element.

[0053] In this embodiment, the voltage value applied to the multiple LED elements of the third optical unit 90 is a predetermined common constant value, and can therefore be expressed as follows. That is, in this embodiment, when the high beam is on, at least a portion of the normal current that would be generated if the off-LED elements of the third optical unit 90 were lit without dimming is supplied to the lit LED elements. For example, for one lit LED element that illuminates the sub-third light distribution pattern P13A, in addition to the amount of current that would be generated if that lit LED element were lit without dimming, a portion of the amount of current that would be generated if the three off-LED elements were lit without dimming is also supplied. Since the voltage value applied to the multiple LED elements of the third optical unit 90 is a constant value, and all of the multiple LED elements are the same LED elements, a lit LED element that is supplied with a portion of the amount of current that would be generated if the off-LED elements were lit without dimming receives approximately 1.3 times the amount of current compared to before the supply. The more current supplied to a lit LED element, the more light is emitted from that lit LED element, and the brighter the sub-third light distribution pattern P13A emitted from that LED element becomes. Similarly, the sub-third light distribution patterns P13B to P13G, the sub-third light distribution pattern P13K, and the sub-third light distribution pattern P13L also become brighter. Note that the entire current that would be supplied to the lit LED elements if the off-LED elements were lit without dimming may be supplied, or a portion of the current that would be supplied to the lit LED elements if the off-LED elements were lit without dimming may be supplied.

[0054] Because more power or current is supplied to the lit LED elements when the unlit LED elements are lit without dimming, the sub-third light distribution patterns P13A to P13G, sub-third light distribution pattern P13K, and sub-third light distribution pattern P13L, as exemplified in Figure 6, are brighter than the sub-third light distribution patterns P13A to P13G, sub-third light distribution pattern P13K, and sub-third light distribution pattern P13L, as exemplified in Figure 3. Also, the sub-third light distribution pattern P13A when the high beam is on (see Figure 6) is brighter than the sub-third light distribution pattern P13A when the low beam is on (see Figure 4). The same applies to the sub-third light distribution patterns P13B to P13G, sub-third light distribution pattern P13K, and sub-third light distribution pattern P13L.

[0055] As described above, the vehicle headlight 10 of this disclosure, when the high beam is on, supplies at least a portion of the normal power that would be generated if the off-LED elements of the third optical unit 90 were lit without dimming to the lit LED elements. In other words, when the off-LED elements of the multiple LED elements are turned off, the power supplied to the lit LED elements can be increased by utilizing at least a portion of the normal power that would be generated if the off-LED elements were lit without dimming. As a result, the third optical unit 90 can reduce glare to the preceding vehicle 1B by turning off the off-LED elements, while supplying more power to the lit LED elements, thereby brightening at least a portion of the cutoff line CL and further improving the visibility of the light distribution pattern.

[0056] Similarly, the vehicle headlight 10 of this disclosure, when the high beam is on, supplies at least a portion of the normal current that would be generated if the off-LED elements of the third optical unit 90 were lit without dimming, to the lit LED elements. In other words, when the off-LED elements of the multiple LED elements are turned off, the current supplied to the lit LED elements can be increased by utilizing at least a portion of the normal current that would be generated if the off-LED elements were lit without dimming. As a result, the third optical unit 90 can brighten at least a portion of the cutoff line CL while suppressing glare to the preceding vehicle 1B, thereby further improving the visibility of the light distribution pattern.

[0057] In this embodiment, the normal power or current when the unlit LED element is lit without dimming is supplied equally to the multiple lit LED elements. Therefore, visibility can be uniformly enhanced throughout the sub-third light distribution patterns P13A to P13G, sub-third light distribution pattern P13K, and sub-third light distribution pattern P13L illuminated by the lit LED elements.

[0058] (Second Embodiment) In the vehicle headlight 10 according to the second embodiment, when the high beam is on, the normal power or normal current when the off LED elements are lit without dimming is supplied unevenly to the multiple lit LED elements. The specific process will be described below. In the description of the second embodiment, the contents that are common with the description of the first embodiment will be omitted.

[0059] Figure 7 illustrates the high-beam light distribution pattern PH2 of the vehicle headlight 10 according to the second embodiment when the high beam is on. In Figure 7, compared to the light distribution pattern illustrated in Figure 3, the illuminated area that is brightly illuminated by the vehicle headlight 10 is shown with darker hatching.

[0060] In this embodiment, when the high beam is on, the normal power or current that would be supplied if the off-LED elements were lit without dimming is supplied unevenly to the multiple lit LED elements. As illustrated in Figure 7, for example, a portion of the normal power may be supplied in greater quantities to one LED element illuminating the sub-third light distribution pattern P13K than to one LED element illuminating the sub-third light distribution pattern P13L. In this case, the other LED element illuminating the sub-third light distribution pattern P13K is supplied with power that is the product of a certain voltage value and the current value that would be supplied if that other LED element were lit without dimming. Furthermore, a portion of the normal power or normal current is also supplied to the other LED element illuminating the sub-third light distribution pattern P13K. For this reason, the sub-third light distribution pattern P13K illustrated in Figure 7 is brighter than the sub-third light distribution pattern P13K illustrated in Figure 3. Furthermore, since a portion of the normal power or normal current is supplied in greater quantities to the other LED element illuminating the sub-third light distribution pattern P13K than to the one LED element illuminating the sub-third light distribution pattern P13L, the sub-third light distribution pattern P13K, as illustrated in Figure 7, becomes brighter than the sub-third light distribution pattern P13L.

[0061] As explained above, in the second embodiment, the normal power or current when the off LED element is lit without dimming is supplied unevenly to the multiple lit LED elements. For example, if you want to make the sub-third light distribution pattern P13K brighter, you can supply more power or current to the LED element that illuminates the sub-third light distribution pattern P13K to improve the visibility of the sub-third light distribution pattern P13K.

[0062] In the second embodiment, normal power or normal current may be supplied in greater quantities to the lit LED elements adjacent to the off-light LED elements than to the lit LED elements that are not adjacent to the off-light LED elements. As illustrated in Figure 7, since there is a preceding vehicle 1B in front of the vehicle, the sub-third light distribution pattern P13J is not illuminated. In this case, the off-light LED elements corresponding to the sub-third light distribution pattern P13J and the lit LED elements corresponding to the sub-third light distribution pattern P13K are adjacent to each other. On the other hand, the off-light LED elements corresponding to the sub-third light distribution pattern P13J are not adjacent to the lit LED elements corresponding to the rightmost sub-third light distribution pattern P13L. Normal power or normal current is supplied in greater quantities to the lit LED elements corresponding to the sub-third light distribution pattern P13K, which are adjacent to the off-light LED elements, than to the lit LED elements corresponding to the sub-third light distribution pattern P13L, which are not adjacent to the off-light LED elements. Therefore, the sub-third light distribution pattern P13K, as illustrated in Figure 7, is brighter than the sub-third light distribution pattern P13L. Similarly, the sub-third beam pattern P13G is brighter than the sub-third beam pattern P13F.

[0063] In this way, when an unlit LED element is lit without dimming, the normal power or current is preferentially supplied to the lit LED element adjacent to the unlit LED element. This allows the cutoff line CL near the preceding vehicle 1B to be brighter, thereby improving visibility.

[0064] In the first and second embodiments, the plurality of LED elements of the third optical unit 90 included a plurality of LED elements that lit up without dimming and at least one LED element that turned off. However, the lighting state of the LED elements is not limited to lit up and off. Some LED elements may light up with dimming. In this case, the plurality of LED elements of the third optical unit 90 includes a plurality of LED elements that lit up and at least one dimming LED element that lit up with dimming.

[0065] For example, suppose a preceding vehicle 1B is located in the area in front of vehicle 1 that corresponds to sub-third light distribution patterns P13H, P13I, and P13J. In this case, the nine lit LED elements light up, illuminating sub-third light distribution patterns P13A through P13G, P13K, and P13L. On the other hand, the three dimming LED elements light up at a reduced brightness, illuminating sub-third light distribution patterns P13H, P13I, and P13J with relatively weak light. The amount of power when the three dimming LED elements are lit without dimming is called normal power. The amount of power when the three dimming LED elements are lit at a reduced brightness is called dimming power. The surplus power obtained by subtracting the dimming power from the normal power may be supplied equally or unevenly to the nine lit LED elements. In this way, even when the dimming LED element is lit at a reduced brightness, the excess power is supplied to the lit LED element, thereby illuminating at least a portion of the cutoff line CL and further improving the visibility of the light distribution pattern.

[0066] In the first and second embodiments, the voltage values ​​applied to the plurality of LED elements of the third optical unit 90 are predetermined common constant values ​​and can also be expressed as follows. For example, suppose that a preceding vehicle 1B is located in the area in front of vehicle 1 that corresponds to sub-third light distribution pattern P13H, sub-third light distribution pattern P13I, and sub-third light distribution pattern P13J. The amount of current when the three dimming LED elements are lit without dimming is defined as the normal current. The amount of current when the three dimming LED elements are lit with dimming is defined as the dimming current. The surplus current obtained by subtracting the dimming current from the normal current may be supplied equally or unevenly to the nine lit LED elements. In this way, even when the dimming LED elements are lit with dimming, the surplus current is supplied to the lit LED elements, so that at least a portion of the cutoff line CL is brightened, and the visibility of the light distribution pattern can be further improved.

[0067] In the first and second embodiments, the multiple LED elements of the third optical unit 90 were all the same LED elements, but these light source elements may be different from each other. Even if the light source elements are different from each other, the normal power is determined by multiplying a constant voltage value by the current value applied when an off-powered LED element or a dimmed LED element is lit without dimming, and is supplied to the lit LED element.

[0068] In the first and second embodiments, the plurality of LED elements in the third optical unit 90 was 12, but the number of plurality of LED elements is not limited to 12. The number of plurality of LED elements may be even or odd. In the first and second embodiments, the plurality of sub-third light distribution patterns are arranged symmetrically on the virtual vertical screen with respect to the V-V line, but the arrangement of the plurality of sub-third light distribution patterns is not limited to symmetry. For example, the number of sub-third light distribution patterns located to the right of the V-V line may be greater than the number of sub-third light distribution patterns located to the left of the V-V line.

[0069] In the first and second embodiments, the current values ​​applied to the multiple LED elements of the third optical unit 90 were changed, but the control of power supply is not limited to this. The lamp control unit 60 of the vehicle headlight 10 may be configured to individually supply an electrical signal (for example, a PWM (Pulse Width Modulation) signal) to each of the multiple LED elements. In this case, the lamp control unit 60 can individually select which LED elements to which an electrical signal is supplied, and can also adjust the duty cycle of the electrical signal for each LED element. In other words, the lamp control unit 60 can select which LED elements to light up or turn off from among the multiple LED elements, and can also change the brightness of each LED element that is lit. By changing the duty cycle by such PWM control, a portion of the normal power that would be supplied to the lit LED elements if the off LED elements were lit without dimming can also be supplied to the lit LED elements.

[0070] In the first and second embodiments, when the high beams are on and there are no objects to block the light, such as the preceding vehicle 1B, all of the LED elements of the third optical unit 90 may be lit. In such a state where the ADB function is stopped, all of the LED elements may be lit, and normally no power is supplied to the lit LED elements.

[0071] In the first and second embodiments, the voltage values ​​applied to the multiple LED elements of the third optical unit 90 were predetermined common constant values, but the voltage values ​​applied to the multiple LED elements may be different. Even if the voltage values ​​applied to the multiple LED elements are different, the normal power when an off-LED element or a dimmed LED element is lit without dimming can be determined by multiplying the voltage value applied to the off-LED element or dimmed LED element by the current value applied to the off-LED element or dimmed LED element, and this normal power can be supplied to the lit LED element.

[0072] (Modification 1) In the first and second embodiments, the cutoff line with a high contrast ratio and the cutoff line with a low contrast ratio can be switched by turning on and off the multiple LED elements of the third optical unit 90. However, if the switching of the multiple LED elements of the third optical unit 90 on and off is too fast, the cutoff line with a high contrast ratio and the cutoff line with a low contrast ratio will switch abruptly, which may cause discomfort to the occupants of the vehicle 1. For example, when the high beam is on for a short period, there may be a switch from the high beam to the low beam. In this case, the off time of the third optical unit 90 when the high beam is on is short, and the third optical unit 90 switches from the off state to the on state when switching from the high beam to the low beam. Therefore, immediately after becoming a cutoff line with a high contrast ratio, it switches to a cutoff line with a low contrast ratio, which may cause discomfort to the occupants of the vehicle 1. Therefore, in the vehicle headlight 10 according to the first embodiment and the modified version 1 of the second embodiment, the following processing is performed.

[0073] Referring to Figure 8, a vehicle headlight 10 according to Modification 1 of the first and second embodiments will be described. The configuration of the vehicle headlight 10 according to Modification 1 is the same as the configuration of the vehicle headlight 10 according to the first and second embodiments.

[0074] Figure 8 is a flowchart showing the processing of the vehicle headlight 10 according to Modification 1. At the start, the vehicle headlight 10 is illuminated in high beam mode.

[0075] As illustrated in Figure 8, at the start, the high beams are on, so the vehicle headlights 10 illuminate the first optical unit 70 and the second optical unit 80 (step S11). At this time, the third optical unit 90 is off.

[0076] Next, the vehicle control unit 50 determines whether the vehicle headlights 10 have switched from high beam to low beam (step S12). The vehicle control unit 50 may, for example, determine the switch from high beam to low beam by receiving a signal from the light switch 40 indicating that a switch operation from high beam to low beam has been performed. The vehicle control unit 50 may, for example, analyze the image data captured by the camera 30 and determine the switch from high beam to low beam according to the surrounding environment of the vehicle 1. Thus, the switch between high beam and low beam may be performed manually or automatically.

[0077] If the vehicle has not switched from high beam on to low beam on (NO in step S12), the vehicle control unit 50 repeats the process in step S12. If the vehicle has switched from high beam on to low beam on (YES in step S12), the vehicle control unit 50 sends a signal to the lamp control unit 60 indicating this. Based on the signal received from the vehicle control unit 50, the lamp control unit 60 turns off the illuminated second optical unit 80 (step S13). By turning off the second optical unit 80, the duration for which the second optical unit 80 remained illuminated when the high beam was on is determined, i.e., the illumination time of the second optical unit 80.

[0078] Next, the lamp control unit 60 determines whether the illumination time of the second optical unit 80 when the high beam is on is shorter than the threshold time (step S14). The threshold time is, for example, 3 seconds. If the illumination time of the second optical unit 80 is longer than the threshold time (NO in step S14), the lamp control unit 60 immediately illuminates the third optical unit 90 (step S15). After that, the lamp control unit 60 terminates its processing.

[0079] On the other hand, if the illumination time of the second optical unit 80 is shorter than the threshold time (YES in step S14), the lamp control unit 60 further determines whether a delay time has elapsed since the second optical unit 80 turned off (step S16). The delay time is, for example, 3 seconds. The lamp control unit 60 may, for example, count a time equivalent to the delay time from the time the second optical unit 80 is turned off and determine whether the counting has finished. The lamp control unit 60 may, for example, have a timer (not shown) that measures time and measure a time equivalent to the delay time from the time it receives a signal from the vehicle control unit 50 indicating that it has switched from high beam illumination to low beam illumination. If the delay time has not elapsed since the second optical unit 80 turned off (NO in step S16), the lamp control unit 60 repeats the process in step S16.

[0080] If the delay time has elapsed since the second optical unit 80 turned off (YES in step S16), the lamp control unit 60 turns on the third optical unit (step S15). After that, the lamp control unit 60 terminates its process.

[0081] Here, we will explain the technical effects of Modification 1 by comparing the case where the answer in step S14 is NO and the case where the answer in step S14 is YES. If the illumination time of the second optical unit 80 is longer than the threshold time (NO in step S14), the third optical unit 90 will have been off for a relatively long time when the high beams were on. In other words, a cutoff line with a large contrast ratio between light and dark will have been formed for a relatively long time. In such a case, even if the third optical unit 90 is illuminated without delay when switching from high beam illumination to low beam illumination (step S15), it is less likely to cause discomfort to the occupants of vehicle 1.

[0082] On the other hand, if the illumination time of the second optical unit 80 is shorter than the threshold time (YES in step S14), then the third optical unit 90 will have been off for a relatively short time when the high beams were on. In other words, a cutoff line with a high contrast ratio of light and dark was formed for only a relatively short time. If, unlike in Modification 1, the third optical unit 90 is immediately illuminated after the second optical unit 80 is turned off when switching from high beam illumination to low beam illumination, then a cutoff line with a low contrast ratio of light and dark will be formed as soon as a cutoff line with a high contrast ratio of light and dark is formed. Such abrupt switching of cutoff lines may cause discomfort to the occupants of vehicle 1.

[0083] However, according to Modification 1, if the illumination time of the second optical unit 80 is shorter than the threshold time (YES in step S14), the third optical unit 90 is illuminated (step S15) after a delay time has elapsed since the second optical unit 80 turned off (YES in step S16). In other words, if the time for which a cutoff line with a high contrast ratio of light and dark is formed is short, a cutoff line with a low contrast ratio of light and dark will be formed with a slight delay. Because a delay time is provided for switching the cutoff line in this way, the cutoff line does not switch abruptly, making it less likely to cause discomfort to the occupants of vehicle 1.

[0084] Furthermore, the lamp control unit 60 may turn on the third optical unit 90 after a delay time has elapsed since the second optical unit 80 turned off, so that at least a portion of the cutoff line gradually brightens (a modification of step S15). Since the brightness of the illumination area of ​​the third optical unit 90 changes relatively slowly, it is less likely to cause discomfort to the occupants of the vehicle 1.

[0085] (Modification 2) Referring to Figure 9, a vehicle headlight 10 according to Modification 2 of the first and second embodiments will be described. The configuration of the vehicle headlight 10 according to Modification 2 is the same as the configuration of the vehicle headlight 10 according to the first embodiment, the second embodiment, and Modification 1.

[0086] Figure 9 is a flowchart showing the process of the vehicle headlight 10 according to the second embodiment. In the process shown in Figure 9, the same reference numerals are used for processes that are the same as those shown in Figure 8, and their descriptions are omitted. At the start, the vehicle headlight 10 is illuminated in low beam mode.

[0087] As illustrated in Figure 9, at startup the low beams are on, so the vehicle headlights 10 illuminate the first optical unit 70 and the third optical unit 90 (step S21). At this time, the second optical unit 80 is off.

[0088] Next, the vehicle control unit 50 determines whether the vehicle headlights 10 have switched from low beam to high beam (step S22). The vehicle control unit 50 may, for example, determine the switch from low beam to high beam by receiving a signal from the light switch 40 indicating that a switch operation from low beam to high beam has been performed.

[0089] If the low beams have not switched to high beams (NO in step S22), the vehicle control unit 50 repeats the process in step S22. If the low beams have switched to high beams (YES in step S22), the vehicle control unit 50 sends a signal to the lamp control unit 60 indicating this. Based on the signal received from the vehicle control unit 50, the lamp control unit 60 turns off the illuminated third optical unit 90 and turns on the off second optical unit 80 (step S23).

[0090] Next, the vehicle control unit 50 determines whether the vehicle headlights 10 have switched from high beam to low beam again (step S12). If the headlights have not switched from high beam to low beam again (NO in step S12), the vehicle control unit 50 repeats the process in step S12. If the headlights have switched from high beam to low beam again (YES in step S12), the vehicle control unit 50 sends a signal to the lamp control unit 60 to indicate this, and the lamp control unit 60 turns off the illuminated second optical unit 80 (step S13).

[0091] Furthermore, the lamp control unit 60 determines whether a delay time has elapsed since the second optical unit 80 turned off (step S16). If the delay time has not elapsed since the second optical unit 80 turned off (NO in step S16), the lamp control unit 60 repeats the process in step S16. If the delay time has elapsed since the second optical unit 80 turned off (YES in step S16), the lamp control unit 60 turns on the third optical unit (step S15). After that, the process returns to before step S22.

[0092] Here, the technical effects of Modification 2 will be explained. As described above, when switching from low beam illumination to high beam illumination (YES in step S22), and then switching again from high beam illumination to low beam illumination (YES in step S12), the third optical unit 90 will repeatedly turn on and off. If, contrary to this disclosure, the second optical unit 80 is turned off and the third optical unit 90 is immediately turned on when switching from high beam illumination to low beam illumination, the cutoff line with a high contrast ratio of light and dark and the cutoff line with a low contrast ratio of light and dark will switch frequently. Such frequent switching of cutoff lines may cause discomfort to the occupants of vehicle 1.

[0093] However, in this example, when switching from high beam on to low beam on again, the second optical unit 80 turns off, and after a delay period has elapsed (YES in step S16), the third optical unit 90 is turned on (step S15). When it is thought that the switching of the cutoff line will be repeated, a cutoff line with a high contrast ratio of light and dark will be formed, followed by a cutoff line with a low contrast ratio of light and dark with a slight delay. In this way, a delay period is provided when the third optical unit 90 turns on again, making it less likely to cause discomfort to the occupants of vehicle 1 due to frequent switching of the cutoff line.

[0094] In the modified example 2, the lamp control unit 60 may also turn on the third optical unit 90 after a delay time has elapsed since the second optical unit 80 turned off, so that at least a portion of the cutoff line gradually brightens (modification of step S15). Since the brightness of the illumination area of ​​the third optical unit 90 changes relatively slowly, it is less likely to cause discomfort to the occupants of the vehicle 1.

[0095] In further modification 2, the lamp control unit 60 may turn off the third optical unit 90 so that at least a portion of the cutoff line gradually dims when switching from low beam illumination to high beam illumination (modification of step S23). Since the brightness of the illumination area of ​​the third optical unit 90 changes relatively slowly, it is less likely to cause discomfort to the occupants of the vehicle 1.

[0096] In Modification 1 and Modification 2, the delay time was set to 3 seconds, but the delay time is not limited to 3 seconds. The delay time may be longer than 3 seconds, for example, 5 seconds. In Modification 1, the threshold time was set to 3 seconds, but the threshold time is not limited to 3 seconds. The threshold time may be longer than 3 seconds, for example, 5 seconds.

[0097] (Third Embodiment) Next, a vehicle headlight 10 according to the third embodiment will be described with reference to Figures 10 to 13. The configuration of the vehicle headlight 10 according to the third embodiment is the same as that of the vehicle headlight 10 according to the first embodiment, so the description will be omitted.

[0098] Figure 10 illustrates the various light distribution patterns emitted by the vehicle headlight 10 according to the third embodiment. In Figure 10, the same reference numerals are used for light distribution patterns that are substantially the same as those described with reference to Figure 3, and redundant explanations are omitted.

[0099] Figure 11 is a diagram illustrating the low beam light distribution pattern PL of the vehicle headlight 10 according to the third embodiment when the low beam is illuminated. Figure 12 is a diagram illustrating the high beam light distribution pattern PH of the vehicle headlight 10Z according to a comparative example when the high beam is illuminated. In Figure 11, the same reference numerals are used for light distribution patterns that are substantially the same as those described with reference to Figure 4, and repeated explanations are omitted. In Figure 12, the same reference numerals are used for light distribution patterns that are substantially the same as those described with reference to Figure 5, and repeated explanations are omitted.

[0100] As illustrated in Figure 12, when the high beams are on, the vehicle headlight 10 illuminates the high beam light distribution pattern PH, which consists of the first light distribution pattern P11 and the second light distribution pattern P12, by illuminating the first optical unit 70 and the second optical unit 80. In the example shown in Figure 12, the area around the preceding vehicle 1B is shielded from light. Therefore, when the high beams are on, the area around the preceding vehicle 1B is shielded from light, and the third light distribution pattern P13 is not illuminated, so the portion C11 of the cutoff line CL located below the preceding vehicle 1B shows a clear difference in brightness.

[0101] By switching the third optical unit 90 on and off, it is possible to switch between a cutoff line with a high contrast ratio and a cutoff line with a low contrast ratio. However, as illustrated in Figure 12, the vehicle headlight 10Z according to the comparative example turns off the third optical unit 90 when the high beam is on, so it is not possible to illuminate the area in front of the vehicle 1 with light compared to when the third optical unit 90 is on. Therefore, it is conceivable to utilize the power that would be generated when the third optical unit 90 is on when it is off. The vehicle headlight 10 of this disclosure turns on the first optical unit 70 and the second optical unit 80 when the high beam is on, and supplies at least a portion of the power that would be generated when the third optical unit 90 is on to at least one of the first optical unit 70 and the second optical unit 80. The details of the third embodiment will be described below.

[0102] In the vehicle headlight 10 according to the third embodiment, when the high beam is on, the power that would be used when the third optical unit 90 is lit is supplied only to the first optical unit 70. The specific process will be described below.

[0103] In the vehicle headlight 10 of this embodiment, the voltage values ​​applied to each optical unit 70, 80, and 90 are predetermined common constant values. In this embodiment, "common constant value" includes not only cases where the values ​​are exactly the same, but also cases where the difference between the two is sufficiently small and they are evaluated as substantially the same value. Furthermore, the current values ​​applied to each optical unit 70, 80, and 90 are assumed to be variables. The power when the third optical unit 90 is lit is obtained by multiplying the voltage value applied to the third optical unit 90 by the current value applied to the third optical unit 90.

[0104] For the sake of brevity, we will assume that the light source 71 of the first optical unit 70 and the light source elements constituting the LED array of the third optical unit 90 are the same LED elements. Furthermore, the number of light sources 71 in the first optical unit 70 and the number of light source elements in the third optical unit 90 are also the same, both being 10.

[0105] When the third optical unit 90 is lit, a constant voltage value and a current value sufficient to light up the 10 LED elements are applied to the third optical unit 90. In the following explanation, the amount of power obtained by multiplying the constant voltage value and the current value sufficient to light up the 10 LED elements will be referred to as the power when the third optical unit 90 is lit.

[0106] When the high beams are on, the third optical unit 90 is turned off. Therefore, when the high beams are on, the power obtained by multiplying a certain voltage value by the current value that lights up the 10 LED elements of the third optical unit 90 can be used for other purposes. In this embodiment, all the power generated when the third optical unit 90 is lit is supplied to the first optical unit 70.

[0107] Figure 13 illustrates the high-beam light distribution pattern of a vehicle headlight 10 according to the third embodiment when the high beam is on. In Figure 13, compared to the light distribution pattern illustrated in Figure 10, the illuminated area that is brighter from the vehicle headlight 10 is shown with darker hatching.

[0108] As illustrated in Figure 13, in this embodiment, when the high beam is on, the power supplied to the first optical unit 70 when the third optical unit 90 is lit is supplied only to the first optical unit 70. Specifically, in addition to the power supplied to the first optical unit 70 as the product of a certain voltage value and the current value that lights up the multiple light sources 71 (10 LED elements), the power supplied to the first optical unit 70 when the third optical unit 90 is lit is also the product of a certain voltage value and the current value that lights up the 10 LED elements of the third optical unit 90. Here, the light sources 71 of the first optical unit 70 and the light source elements that constitute the LED array of the third optical unit 90 are the same LED elements, and the number of light sources 71 and the number of light source elements are also the same. Therefore, the light sources 71 of the first optical unit 70 that are supplied with the power supplied when the third optical unit 90 is lit receive twice the power compared to before the supply. The more power supplied to the first optical unit 70, the more light is emitted from the first optical unit 70, and the brighter the first light distribution pattern P111 emitted from the first optical unit 70 becomes. Furthermore, when the third optical unit 90 is lit, all of its power may be supplied to the first optical unit 70, or only a portion of the power supplied when the third optical unit 90 is lit may be supplied to the first optical unit 70.

[0109] In this embodiment, the voltage values ​​applied to each optical unit 70, 80, and 90 are predetermined common constant values, and can therefore be expressed as follows. That is, in this embodiment, when the high beam is on, the current that would be supplied to the third optical unit 90 when it is lit is supplied only to the first optical unit 70. Specifically, in addition to the amount of current that would be supplied to the first optical unit 70 to light up the multiple light sources 71 (10 LED elements), the amount of current that would be supplied when the third optical unit 90 is lit is also supplied. Since the light sources 71 of the first optical unit 70 and the light source elements that make up the LED array of the third optical unit 90 are the same LED elements, and the number of light sources 71 and the number of light source elements are also the same, the light source 71 of the first optical unit 70, to which the current that would be supplied when the third optical unit 90 is lit is supplied, receives twice the amount of current compared to before the supply. The more current supplied to the first optical unit 70, the more light is emitted from the first optical unit 70, and the brighter the first light distribution pattern P111 emitted from the first optical unit 70 becomes. Furthermore, when the third optical unit 90 is lit, the entire current may be supplied to the first optical unit 70, or a portion of the current when the third optical unit 90 is lit may be supplied to the first optical unit 70.

[0110] When the third optical unit 90 is lit, more power or current is supplied to the first optical unit 70. Therefore, the first light distribution pattern P111 irradiated from the first optical unit 70, as illustrated in Figure 13, is brighter than the first light distribution pattern P11 irradiated from the first optical unit 70, as illustrated in Figure 10. In addition, a portion of the first light distribution pattern P111 when the high beam is lit is designated as PLA1 (see Figure 13), and a portion of the first light distribution pattern P11 when the low beam is lit is designated as PLA2 (see Figure 11). The portion PLA1 and portion PLA2 are parts of the light distribution pattern irradiated from one common light source 71 among the multiple light sources 71 of the first optical unit 70, and are irradiation areas that do not overlap with the third light distribution pattern P13 irradiated from the third optical unit 90 when the low beam is lit. In such a case, the portion PLA1 of the first light distribution pattern P111 when the high beam is lit is brighter than the portion PLA2 of the first light distribution pattern P11 when the low beam is lit.

[0111] As described above, the vehicle headlight 10 of this disclosure supplies at least a portion of the power that the third optical unit 90 generates when the high beam is on to at least one of the first optical unit 70 and the second optical unit 80. In other words, when the third optical unit 90 is turned off, at least a portion of the power that the third optical unit 90 generates when it is on can be used to increase the power supplied to at least one of the first optical unit 70 and the second optical unit 80. As a result, at least one of the area below the cutoff line CL and the area above the cutoff line CL can be made brighter, and the visibility of the light distribution pattern can be further improved.

[0112] Similarly, the vehicle headlight 10 of this disclosure supplies at least a portion of the current generated when the third optical unit 90 is illuminated to at least one of the first optical unit 70 and the second optical unit 80 when the high beam is on. When the third optical unit 90 is turned off, at least a portion of the current generated when the third optical unit 90 is illuminated can be used to increase the current supplied to at least one of the first optical unit 70 and the second optical unit 80, thereby further improving the visibility of the light distribution pattern.

[0113] In the third embodiment, when the high beam is on, the power or current supplied to the third optical unit 90 when it is lit is supplied only to the first optical unit 70. When the third optical unit 90 is turned off, the power or current supplied to the first optical unit 70 can be increased by utilizing the power or current that would have been supplied if the third optical unit 90 had been lit. As a result, when the high beam is on, the cutoff line CL and the area below the cutoff line CL can be made brighter.

[0114] (Fourth Embodiment) In the fourth embodiment, the vehicle headlight 10 supplies power to both the first optical unit 70 and the second optical unit 80 when the third optical unit 90 is lit while the high beam is on. The specific process will be described below. In the description of the fourth embodiment, the contents that are common with the description of the third embodiment will be omitted.

[0115] Figure 14 illustrates the high-beam light distribution pattern of the vehicle headlight 10 according to the fourth embodiment when the high beam is on. In Figure 14, compared to the light distribution pattern illustrated in Figure 10, the illuminated area that is brighter from the vehicle headlight 10 is shown with darker hatching.

[0116] In this embodiment, when the high beam is on, the power generated when the third optical unit 90 is lit is supplied to the first optical unit 70 and the second optical unit 80. For example, in addition to the power generated by multiplying a certain voltage value by the current value that lights up the multiple light sources 71 (10 LED elements), the first optical unit 70 is also supplied with power generated by multiplying a certain voltage value by the current value that lights up the five LED elements of the third optical unit 90. As the power supplied to the first optical unit 70 increases, the first light distribution pattern P112 irradiated from the first optical unit 70 becomes brighter. Note that all the power generated when the third optical unit 90 is lit may be supplied to the first optical unit 70 and the second optical unit 80, or only a portion of the power generated when the third optical unit 90 is lit may be supplied to the first optical unit 70 and the second optical unit 80.

[0117] In this embodiment as well, the voltage values ​​applied to each optical unit 70, 80, and 90 are predetermined common constant values, and can therefore be expressed as follows. That is, in this embodiment, when the high beam is lit, the current that would be supplied to the third optical unit 90 when it is lit is supplied to the first optical unit 70 and the second optical unit 80. For example, in addition to the amount of current that lights up multiple light sources 71 (10 LED elements) to the first optical unit 70, the amount of current that lights up the five LED elements of the third optical unit 90 is also supplied as part of the current that would be supplied when the third optical unit 90 is lit. Since the light sources 71 of the first optical unit 70 and the light source elements that constitute the LED array of the third optical unit 90 are the same LED elements, and the number of light sources 71 and the number of light source elements are also the same, the light source 71 of the first optical unit 70, to which the current that would be supplied when the third optical unit 90 is lit is supplied, receives 1.5 times the amount of current compared to before the supply. The more current supplied to the first optical unit 70, the more light is emitted from the first optical unit 70, and the brighter the first light distribution pattern P112 emitted from the first optical unit 70 becomes. Note that when the third optical unit 90 is lit, all of the current may be supplied to the first optical unit 70 and the second optical unit 80, or a portion of the current when the third optical unit 90 is lit may be supplied to the first optical unit 70 and the second optical unit 80.

[0118] Thus, the first light distribution pattern P112 irradiated from the first optical unit 70, as illustrated in Figure 14, becomes brighter than the first light distribution pattern P11 irradiated from the first optical unit 70, as illustrated in Figure 10.

[0119] Similarly, in addition to the power obtained by multiplying a constant voltage value by the current value that lights up the light source 81, the second optical unit 80 is also supplied with power obtained by multiplying a constant voltage value by the current value that lights up the other five LED elements of the third optical unit 90. As the power to the second optical unit 80 increases, the second light distribution pattern P122 irradiated from the second optical unit 80 becomes brighter. Alternatively, it can be said that in addition to the current amount that lights up the light source 81, the second optical unit 80 is also supplied with the current amount that lights up the other five LED elements of the third optical unit 90. As the current to the second optical unit 80 increases, the second light distribution pattern P122 irradiated from the second optical unit 80 becomes brighter. Thus, the second light distribution pattern P122 irradiated from the second optical unit 80, as illustrated in Figure 14, is brighter than the second light distribution pattern P12 irradiated from the second optical unit 80, as illustrated in Figure 10. Furthermore, when the high beams are on and there is a preceding vehicle 1B in front of vehicle 1, at least a portion of the second light distribution pattern P122, and a portion of the region other than the region corresponding to the preceding vehicle 1B, is defined as PHA1 (see Figure 14), and when the high beams are on and there is no preceding vehicle 1B in front of vehicle 1, at least a portion of the second light distribution pattern P12 is defined as PHA2 (see Figure 10). Partial PHA1 and partial PHA2 are assumed to be a portion of the light distribution pattern illuminated from one common micro-LED light-emitting element among the multiple micro-LED light-emitting elements of the second optical unit 80. In such a case, at least a portion of PHA1, when the high beams are on and there is a preceding vehicle 1B in front of vehicle 1, and a portion of the region other than the region corresponding to the preceding vehicle 1B, is brighter than at least a portion of PHA2, when the high beams are on and there is no preceding vehicle 1B in front of vehicle 1.

[0120] As described above, in the fourth embodiment, when the high beam is on, at least a portion of the power generated when the third optical unit 90 is lit is supplied to the first optical unit 70 and the second optical unit 80. When the third optical unit 90 is turned off, at least a portion of the power generated when the third optical unit 90 is lit can be used to increase the power supplied to the first optical unit 70 and the second optical unit 80. As a result, when the high beam is on, all areas, including the cutoff line CL, the area below the cutoff line CL, and the area above the cutoff line CL, can be illuminated.

[0121] Similarly, in the fourth embodiment, when the high beam is on, at least a portion of the current generated when the third optical unit 90 is lit is supplied to the first optical unit 70 and the second optical unit 80. When the third optical unit 90 is turned off, at least a portion of the current generated when the third optical unit 90 is lit can be used to increase the current supplied to the first optical unit 70 and the second optical unit 80, thereby illuminating the entire area when the high beam is on.

[0122] The illumination area of ​​the second optical unit 80 is divided into multiple regions, each of which can independently change its illumination state. When the high beam is on, at least a portion of the power when the third optical unit 90 is lit may be supplied to the second optical unit 80 such that the region containing the V-V line of the virtual vertical screen becomes brighter than the other regions (see Figure 14). Specifically, among the multiple micro-LED light-emitting elements constituting the light source 81, the micro-LED light-emitting element that illuminates the region containing the V-V line of the virtual vertical screen receives more power when the third optical unit 90 is lit compared to the other micro-LED light-emitting elements. Because the power supplied to the micro-LED light-emitting element that illuminates the region containing the V-V line of the virtual vertical screen increases, the region containing the V-V line of the virtual vertical screen becomes brighter. Therefore, as illustrated in Figure 14, the region containing the V-V line illuminated by the second optical unit 80 becomes brighter than the other regions.

[0123] In the fourth embodiment, when the high beam is on, at least a portion of the power when the third optical unit 90 is lit is supplied equally to the first optical unit 70 and the second optical unit 80, but the power supply is not limited to equal distribution. For example, the first optical unit 70 may be supplied with power equal to the product of a constant voltage value and the current value that lights up the seven LED elements of the third optical unit 90, and the second optical unit 80 may be supplied with power equal to the product of a constant voltage value and the current value that lights up the three LED elements of the third optical unit 90. In this way, when the third optical unit 90 is lit, more power may be supplied to the first optical unit 70 than to the second optical unit 80. Conversely, when the third optical unit 90 is lit, more power may be supplied to the second optical unit 80 than to the first optical unit 70.

[0124] In the third and fourth embodiments, the light source 71 of the first optical unit 70 and the light source elements constituting the LED array of the third optical unit 90 were the same LED elements, but these light source elements may be different from each other. In the third and fourth embodiments, the number of light source 71s of the first optical unit 70 and the number of light source elements of the third optical unit 90 were the same, but these light sources may be different from each other. Even if the light source elements are different from each other or the number of light sources is different, the power when the third optical unit 90 is lit can be determined by multiplying a certain voltage value by a current value that lights up all the light source elements of the third optical unit 90, and this power can be supplied to at least one of the first optical unit 70 and the second optical unit 80.

[0125] In the third and fourth embodiments, the current values ​​applied to the first optical unit 70, the second optical unit 80, and the third optical unit 90 were varied, but the control of power supply is not limited to these. The lamp control unit 60 of the vehicle headlight 10 may be configured to individually supply an electrical signal (for example, a PWM (Pulse Width Modulation) signal) to each of the plurality of light source elements provided in each optical unit. In this case, the lamp control unit 60 can individually select the light source elements to which the electrical signal is supplied, and can adjust the duty cycle of the electrical signal for each light source element. In other words, the lamp control unit 60 can select the light-emitting elements to be lit or turned off from among the plurality of light source elements, and can change the brightness of each lit light source element. By changing the duty cycle by such PWM control, power when the third optical unit 90 is lit can be supplied to at least one of the first optical unit 70 and the second optical unit 80.

[0126] In the third and fourth embodiments, the third optical unit 90 may be illuminated when the high beams are on and there are no objects to block the light, such as the preceding vehicle 1B. In such a state where the ADB function is stopped, the third optical unit 90 may be illuminated, and the power supplied when the third optical unit 90 is illuminated will not be supplied to at least one of the first optical unit 70 and the second optical unit 80.

[0127] In the third and fourth embodiments, the voltage values ​​applied to each optical unit 70, 80, and 90 were predetermined common constant values, but the voltage values ​​applied to each optical unit 70, 80, and 90 may be different. Even if the voltage values ​​applied to each optical unit 70, 80, and 90 are different, the power when the third optical unit 90 is lit can be determined by multiplying the voltage value applied to the third optical unit 90 by the current value that lights up all the light source elements of the third optical unit 90, and this power can be supplied to at least one of the first optical unit 70 and the second optical unit 80.

[0128] The vehicle headlight 10 according to the third and fourth embodiments may also undergo the processing described in Modification 1 or Modification 2 above.

[0129] (Modification 3) In Modification 1 and Modification 2, the third optical unit 90 has a plurality of light sources that change their lighting state independently of each other, and the lamp control unit 60 lights up all light sources when the third optical unit 90 is lit and turns off all light sources when the third optical unit 90 is turned off. However, the on / off switching of the third optical unit 90 is not limited to this. For example, when the third optical unit 90 is lit, the lamp control unit 60 may turn off some of the light sources instead of lighting all of them. Similarly, when the third optical unit 90 is turned off, the lamp control unit 60 may turn on some of the light sources instead of turning off all of them.

[0130] While embodiments of this disclosure have been described above, it goes without saying that the technical scope of this disclosure should not be interpreted as being limited by the description of these embodiments. These embodiments are merely examples, and it will be understood by those skilled in the art that various modifications of the embodiments are possible within the scope of the disclosure described in the claims. The technical scope of this disclosure should be determined based on the scope of the disclosure described in the claims and its equivalents.

[0131] The configurations described in each of the items listed below also constitute part of this disclosure. Item 1: A vehicle headlight installed on a vehicle, comprising: a cutoff line; a first optical unit that irradiates light to a region including at least a region below the cutoff line; a second optical unit that can irradiate light to a region including at least a region above the cutoff line and can dim any region therein; and a third optical unit that irradiates light so as to overlap at least a portion of the cutoff line, wherein the third optical unit has a plurality of light sources whose lighting state can be changed independently of each other; when the high beam is on, the first optical unit, the second optical unit, and some of the plurality of light sources of the third optical unit are lit, and some of the other plurality of light sources of the third optical unit are lit at a dimmed level; when the low beam is on, all of the plurality of light sources of the first optical unit and the third optical unit are lit; and when the high beam is on, at least a portion of the normal power that would be generated if the other plurality of light sources of the third optical unit that are dimmed were lit is supplied to the lit light sources. Item 2: The vehicle headlight according to Item 1, wherein when the high beam is illuminated, the plurality of light sources comprises a plurality of illuminated light sources and at least one dimmed light source that illuminates at a reduced brightness, and the surplus power obtained by subtracting the dimmed power when the dimmed light source illuminates at a reduced brightness from the normal power is supplied equally to the plurality of illuminated light sources. Item 3: The vehicle headlight according to Item 1, wherein when the high beam is illuminated, the plurality of light sources comprises a plurality of illuminated light sources and at least one dimmed light source that illuminates at a reduced brightness, and the surplus power obtained by subtracting the dimmed power when the dimmed light source illuminates at a reduced brightness from the normal power is supplied unevenly to the plurality of illuminated light sources. Item 4: The vehicle headlight according to Item 3, wherein the surplus power is supplied in greater quantities to the illuminated light source adjacent to the dimmed light source than to the illuminated light source that is not adjacent to the dimmed light source.Item 5: A vehicle headlight according to any one of items 1 to 4, wherein when switching from the high beam to the low beam, if the illumination time of the second optical unit is shorter than a predetermined threshold time, the third optical unit is illuminated after a predetermined delay time has elapsed since the second optical unit turned off. Item 6: A vehicle headlight according to any one of items 1 to 4, wherein when switching from the low beam to the high beam, and then switching again from the high beam to the low beam, the third optical unit is illuminated again after a predetermined delay time has elapsed since the second optical unit turned off. Item 7: A vehicle headlight installed on a vehicle, comprising: a cutoff line; a first optical unit that irradiates light to a region including at least a region below the cutoff line; a second optical unit capable of irradiating light to a region including at least a region above the cutoff line, and capable of dimming any region therein; and a third optical unit that irradiates light so as to overlap at least a portion of the cutoff line, wherein the third optical unit has a plurality of light sources whose lighting state can be changed independently of each other; when the high beam is on, the first optical unit, the second optical unit, and some of the plurality of light sources of the third optical unit are lit, and some of the other plurality of light sources of the third optical unit are lit with dimming enabled; when the low beam is on, all of the plurality of light sources of the first optical unit and the third optical unit are lit; and when the high beam is on, at least a portion of the normal current that would be generated if some of the other plurality of light sources of the third optical unit were lit without dimming is supplied to the lit light sources.Item 8: A vehicle headlight installed on a vehicle, comprising: a cutoff line; a first optical unit that irradiates light to an area including at least an area below the cutoff line; a second optical unit capable of irradiating light to an area including at least an area above the cutoff line, and capable of dimming any area therein; and a third optical unit that irradiates light so as to overlap at least a portion of the cutoff line, wherein the third optical unit has a plurality of light sources whose illumination state can be changed independently of each other; when the high beam is on, the first optical unit, the second optical unit, and some of the plurality of light sources of the third optical unit are on, and some of the other plurality of light sources of the third optical unit are on with dimming; when the low beam is on, all of the plurality of light sources of the first optical unit and the third optical unit are on; and at least a portion of the illumination area irradiated by the some light sources that are on without dimming when the high beam is on is brighter than the illumination area irradiated by the some light sources that are on when the low beam is on. Item 9: A vehicle headlight installed on a vehicle, comprising: a cutoff line; a first optical unit that irradiates light to a region including at least a region below the cutoff line; a second optical unit that can irradiate light to a region including at least a region above the cutoff line and can dim any region thereof; and a third optical unit that irradiates light so as to overlap at least a portion of the cutoff line, wherein when the high beam is on, the first optical unit and the second optical unit are lit, and at least a portion of the power when the third optical unit is lit is supplied to at least one of the first optical unit and the second optical unit; and when the low beam is on, the first optical unit and the third optical unit are lit. Item 10: The vehicle headlight according to Item 9, wherein when the high beam is on, at least a portion of the power when the third optical unit is lit is supplied only to the first optical unit.Item 11: A vehicle headlight according to Item 9, wherein at least a portion of the power supplied to the first optical unit and the second optical unit when the high beam is on is supplied to the first optical unit and the second optical unit. Item 12: A vehicle headlight according to Item 11, wherein the illumination area of ​​the second optical unit is divided into a plurality of areas in which any area can change its illumination state independently of each other, and wherein at least a portion of the power supplied to the second optical unit when the high beam is on is supplied to the second optical unit such that the area containing the V-V line of a virtual vertical screen positioned at a predetermined distance from the vehicle becomes brighter than the other areas. Item 13: A vehicle headlight according to any one of Items 9 to 12, wherein when switching from the high beam on to the low beam on, if the illumination time of the second optical unit is shorter than a predetermined threshold time, the third optical unit is illuminated after a predetermined delay time has elapsed since the second optical unit turned off. Item 14: A vehicle headlight according to any one of items 9 to 12, wherein when switching from low beam illumination to high beam illumination, and then switching again from high beam illumination to low beam illumination, the third optical unit is illuminated again after a predetermined delay time has elapsed since the second optical unit turned off. Item 15: A vehicle headlight installed on a vehicle, comprising: a cutoff line; a first optical unit that irradiates light to a region including at least a region below the cutoff line; a second optical unit that can irradiate light to a region including at least a region above the cutoff line and can dim any region therein; and a third optical unit that irradiates light so as to overlap at least a portion of the cutoff line, wherein when the high beam is illuminated, the first optical unit and the second optical unit are illuminated, and at least a portion of the current when the third optical unit is illuminated is supplied to at least one of the first optical unit and the second optical unit; and when the low beam is illuminated, the first optical unit and the third optical unit are illuminated.Item 16: A vehicle headlight provided on a vehicle, comprising: a cutoff line; a first optical unit that illuminates a region including at least a region below the cutoff line; a second optical unit capable of illuminating a region including at least a region above the cutoff line and capable of dimming any region thereof; and a third optical unit that illuminates light so as to overlap at least a portion of the cutoff line, wherein when the high beam is on, the first optical unit and the second optical unit are illuminated; when the low beam is on, the first optical unit and the third optical unit are illuminated; and at least a portion of the region including the lower region when the high beam is on is brighter than at least a portion of the region including the lower region when the low beam is on. Item 17: A vehicle headlight provided on a vehicle, comprising: a cutoff line; a first optical unit that irradiates light to an area including at least an area below the cutoff line; a second optical unit capable of irradiating light to an area including at least an area above the cutoff line and capable of dimming any area therein; and a third optical unit that irradiates light so as to overlap at least a portion of the cutoff line, wherein when the high beam is on, the first optical unit and the second optical unit are illuminated; when the low beam is on, the first optical unit and the third optical unit are illuminated; and when the high beam is on, at least a portion of the area including the upper area when there is a vehicle ahead of the vehicle, and excluding the area corresponding to the vehicle ahead, is brighter than at least a portion of the area including the upper area when the high beam is on and there is no vehicle ahead of the vehicle.

[0132] This application claims priority under Japanese application No. 2025-011590 filed on 27 January 2025 and Japanese application No. 2025-008898 filed on 22 January 2025, and incorporates all the provisions contained in the said Japanese applications.

Claims

1. A vehicle headlight installed on a vehicle, comprising: a cutoff line; a first optical unit that irradiates light to a region including at least a region below the cutoff line; a second optical unit that can irradiate light to a region including at least a region above the cutoff line and can dim any region therein; and a third optical unit that irradiates light so as to overlap at least a portion of the cutoff line, wherein the third optical unit has a plurality of light sources whose lighting state can be changed independently of each other; when the high beam is on, the first optical unit, the second optical unit, and some of the plurality of light sources of the third optical unit are lit, and some of the other plurality of light sources of the third optical unit are lit at a dimmed level; when the low beam is on, all of the plurality of light sources of the first optical unit and the third optical unit are lit; and when the high beam is on, at least a portion of the normal power that would be generated if the other plurality of light sources of the third optical unit that are dimmed were lit is supplied to the lit light sources.

2. When the high beam is illuminated, the plurality of light sources comprises a plurality of illuminated light sources and at least one dimmed light source that illuminates at a reduced brightness, and the surplus power obtained by subtracting the dimmed power when the dimmed light source illuminates at a reduced brightness from the normal power is supplied equally to the plurality of illuminated light sources, as described in claim 1.

3. When the high beam is illuminated, the plurality of light sources comprises a plurality of illuminated light sources and at least one dimmed light source that illuminates at a reduced brightness, and the surplus power obtained by subtracting the dimmed power when the dimmed light source illuminates at a reduced brightness from the normal power is supplied unevenly to the plurality of illuminated light sources, as described in claim 1.

4. The headlight for a vehicle according to claim 3, wherein the surplus power is supplied in greater quantities to the illuminating light source adjacent to the dimming light source than to the illuminating light source not adjacent to the dimming light source.

5. When switching from high beam illumination to low beam illumination, if the illumination time of the second optical unit is shorter than a predetermined threshold time, the third optical unit is illuminated after a predetermined delay time has elapsed since the second optical unit turned off, as described in any one of claims 1 to 4.

6. When switching from the low beam to the high beam, and then switching back from the high beam to the low beam, the third optical unit is illuminated again after a predetermined delay time has elapsed since the second optical unit turned off, as described in any one of claims 1 to 4.

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