Vehicle lamp, lighting device for active sensor, gated camera

Abstract

The vehicle lighting fixture includes a marker light (330) and an illumination unit (400) for an active sensor. The illumination unit (400) includes a near-infrared light source (410) and a light guide (420). The light guide (420) receives the emitted light from the near-infrared light source (410) and emits illumination light with a prescribed light distribution from its emission surface (422). The light guide (420) is configured such that its back surface (424) faces the light-emitting surface of the marker light (330), and emits the emitted light from the marker light (330) received on its back surface (424) from its emission surface (422).

Description

Technical Field

[0001] This invention relates to active sensors. Background Technology

[0002] To enable autonomous driving or automatic control of headlight beam distribution, an object recognition system is used to sense the position and type of objects present around the vehicle. This system includes sensors and a processing unit that analyzes the sensor output. Sensors are selected from a variety of options, such as cameras, LiDAR (Light Detection and Ranging), laser imaging detection and ranking, millimeter-wave radar, ultrasonic sonar, and active sensors, taking into account application, required accuracy, or cost.

[0003] A typical SLR camera cannot obtain depth information. Therefore, it is difficult to separate multiple overlapping objects located at different distances.

[0004] As a camera capable of obtaining depth information, the Time-of-Flight (TOF) camera is known. A TOF camera projects infrared light through a light-emitting device, measures the time it takes for the reflected light to return to the image sensor, and obtains a TOF image that converts the time of flight into distance information.

[0005] As an active sensor to replace the TOF camera, a gating camera (or gated camera) solution has been proposed (Patent Documents 1 and 2). The gating camera divides the shooting area into multiple ranges and adjusts the exposure timing and exposure time for each range to capture images. This results in slice images for each object range, with each slice image containing only the objects within its corresponding range.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2009-257983

[0009] Patent Document 2: International Publication WO2017 / 110413A1 Summary of the Invention

[0010] The technical problem that the invention aims to solve

[0011] 1. When a lighting device that is an active sensor uses near-infrared light, a portion of its spectrum is perceived as red by the human eye. Therefore, it would be against regulations to install it in a headlight without taking countermeasures against this.

[0012] One of the solutions disclosed herein is derived in view of the relevant circumstances, and one of its exemplary purposes is to provide a vehicle lamp that meets regulatory requirements.

[0013] 2. The inventors of this invention have studied the integration of an active sensor lighting device into vehicle lighting fixtures.

[0014] Vehicle lighting fixtures include existing low beams, high beams, position lights (side marker lights), and turn indicators. Illumination devices for active sensors require light distribution that covers the field of view of the image sensor, while also being configured to not impair the functionality of existing lights, thus facing constraints in size and shape.

[0015] One aspect of this disclosure is derived in the context of relevant circumstances, and one of its exemplary purposes is to provide a vehicle lamp with a built-in lighting device for an active sensor.

[0016] When using a laser diode as an active sensor, the lighting device forms a light distribution adapted to the field of view and needs to meet laser safety standards.

[0017] One aspect of this disclosure is derived in the context of relevant circumstances, and one of its exemplary purposes is to provide a lighting device that can balance appropriate light distribution with laser safety standards.

[0018] Methods for solving technical problems

[0019] 1. A vehicle lighting fixture according to one aspect of this disclosure includes a white lamp and an illumination device for an active sensor. The illumination device includes a near-infrared light source and a light guide that receives the emitted light from the near-infrared light source and emits illumination light with a predetermined light distribution from an emitting surface. The light guide is configured such that its back side faces the emitting surface of the white lamp, and emits the emitted light from the white lamp received on its back side from the emitting surface.

[0020] 2. One aspect of the vehicle lighting fixture disclosed herein includes an illumination device for an active sensor. The illumination device includes: a semiconductor light source that emits an infrared beam; and a light guide that receives the infrared beam at an incident surface and emits illumination light with a predetermined light distribution from an exit surface.

[0021] 3. An illumination device for an active sensor according to one embodiment of the present disclosure includes: a plurality of laser diodes; a plurality of light-collecting lenses, each disposed in the optical path of an outgoing beam corresponding to the plurality of laser diodes, so that the outgoing beam is nearly parallel; and a compound eye lens, which diffuses the outgoing light of the plurality of light-collecting lenses.

[0022] Invention Effects

[0023] According to one aspect of this disclosure, regulations can be met. According to one aspect of this disclosure, a vehicle luminaire with a built-in active sensor can be provided. According to one aspect of this disclosure, appropriate light distribution and laser safety standards can be met. Attached Figure Description

[0024] Figure 1 This is a block diagram of the sensing system according to Implementation Method 1.

[0025] Figure 2 This is a diagram illustrating the operation of a gated camera.

[0026] Figure 3 (a) and (b) are diagrams illustrating the images obtained by the gated camera.

[0027] Figure 4 It is a 3D image of a car equipped with a gate camera.

[0028] Figure 5 This is a diagram showing the structure of a headlight.

[0029] Figure 6 This is an exploded perspective view of the headlight in Embodiment 1.

[0030] Figure 7 yes Figure 6 A top view of the headlights.

[0031] Figure 8 This is an exploded 3D view of the lighting unit.

[0032] Figure 9 (a) is a three-dimensional view of the lighting unit. Figure 9 (b) is a top view of the lighting unit.

[0033] Figure 10 (a) and (b) are simulation results of the light distribution pattern of the lighting unit of Embodiment 1.

[0034] Figure 11 (a) and (b) are diagrams illustrating the causes of multiple peaks within the light distribution.

[0035] Figure 12 (a) and (b) are diagrams showing the light guide of modified example 1.

[0036] Figure 13 (a) and (b) are diagrams showing the simulation results of the light distribution pattern when using the light guide of modified example 1.

[0037] Figure 14 (a) and (b) are diagrams showing the light guide of modified example 2.

[0038] Figure 15This is a graph showing the simulation results of the vertical light distribution in variant example 2.

[0039] Figure 16 (a) and (b) are diagrams showing the light guide of modified example 3.

[0040] Figure 17 This is a diagram showing the light guide of modified example 4.

[0041] Figure 18 (a) and (b) are schematic front views showing the layout of the lighting units.

[0042] Figure 19 This is an exploded perspective view of the headlight in Embodiment 2.

[0043] Figure 20 yes Figure 19 An exploded perspective view of the lighting unit.

[0044] Figure 21 Figure (a) is a diagram showing an example of the structure of a light-collecting lens. Figure 21 (b) is a stereoscopic view of the compound eye lens.

[0045] Figure 22 (a) is a cross-sectional view of the lighting unit. Figure 22 (b) is a perspective view of the lighting unit.

[0046] Figure 23 (a) and (b) are the light diagrams of the lighting unit.

[0047] Figure 24 This is a graph showing the brightness distribution (simulation results) of the emitted beam from the lighting unit. Detailed Implementation

[0048] This summary provides an overview of several exemplary embodiments of this disclosure. This summary serves as a preface to the detailed description that follows, and is intended to provide a basic understanding of the embodiments, briefly illustrating several concepts of one or more embodiments, and is not intended to limit the scope of the invention or disclosure. This summary is not a comprehensive overview of all conceivable embodiments, and is not intended to identify essential elements of all embodiments or to define the scope of some or all of the solutions. For convenience, "an embodiment" is sometimes used to refer to one or more embodiments (examples or variations) disclosed in this specification.

[0049] 1. A vehicle lamp according to one embodiment includes a white lamp and an illumination device for an active sensor. The illumination device includes: a near-infrared light source; and a light guide that receives the emitted light from the near-infrared light source and emits illumination light with a predetermined light distribution from an emission surface. The light guide is configured such that its back side faces the emitting surface of the white lamp, and emits the emitted light from the white lamp received on its back side from the emission surface.

[0050] According to this structure, near-infrared light is emitted in overlap with white light, thus preventing it from being perceived as red and meeting regulatory requirements.

[0051] In one embodiment, the white light can be a marker light. The marker light plays an important role in shaping the impression of the headlight's design, and by overlapping the marker light and the components for the active sensor, the illumination function of the active sensor can be added without compromising the headlight's design.

[0052] In one embodiment, multiple steps separated along the optical axis of the near-infrared light source may be provided on the back side of the light guide.

[0053] In one embodiment, the white lamp may include a white light source and a light guide for guiding the white light from the white light source. The white light source and the near-infrared light source may be mounted on the same substrate. Thus, the white light source, the near-infrared light source, and their driving circuitry can be integrated into one location within the headlight.

[0054] In one embodiment, the lighting device and the white lamp can be modularized.

[0055] 2. One embodiment of a vehicle lamp includes an illumination device for an active sensor. The illumination device includes: a semiconductor light source that emits an infrared beam; and a light guide that receives the infrared beam at an incident surface and emits illumination light with a predetermined light distribution from an exiting surface.

[0056] Compared to using lens optics or reflective optics, the use of light guides increases the freedom of shape or size of the lighting device, allowing it to be housed within the headlight housing without compromising the functionality of the existing lamp.

[0057] Furthermore, when a light guide transmits white light, it is perceived as emitting a whitish glow due to internal reflection or diffusion. Therefore, while light guides have historically been used in lighting systems intended for external viewing, such as marker lights, their use in lighting systems intended for illuminating objects, such as low beams or high beams, is less effective. In this regard, by setting the illumination light for active sensors to infrared light, even when a light guide is used in the optical system for forming the illumination light, it will not be perceived as emitting a whitish glow.

[0058] In one embodiment, multiple steps (reflection patterns) separated along the optical axis of the semiconductor light source may be provided on the back side of the light guide. By utilizing reflections based on multiple steps, a horizontally extended illumination light distribution can be formed in front of the vehicle, covering the entire horizontal field of view of the image sensor.

[0059] In one embodiment, the exit surface of the light guide may have curvature in the vertical direction. Therefore, the vertical light distribution of the illumination light emitted from the exit surface of the light guide can be controlled according to the curvature.

[0060] In one embodiment, the sagittal plane of the light guide can also be an inverted cone facing the front of the vehicle. If the infrared beam is reflected on the upper and lower surfaces of the light guide, the luminous intensity distribution of the light will have multiple peaks in the vertical direction. However, by setting the shape to inverted cone, the reflection in the upper and lower surfaces of the light guide can be suppressed, and the generation of multiple peaks can be suppressed.

[0061] In one embodiment, an absorbing material may be included, which is attached to at least one of the upper and lower surfaces of the light guide to absorb infrared light beams. This reduces reflected light on the upper and lower surfaces of the light guide and suppresses the generation of multiple peaks.

[0062] In one embodiment, the incident surface of the light guide may have curvature in the horizontal direction. By setting the curvature in such a way that the infrared beam inside the light guide is nearly parallel (collimated), total internal reflection of the infrared beam at the exit surface of the light guide can be suppressed. Alternatively, the horizontal distribution of the illumination light emitted from the exit surface of the light guide can be controlled according to the curvature of the incident surface.

[0063] In one embodiment, a semiconductor light source may be arranged on the outside of the vehicle within the vehicle lamp, with its optical axis facing the center of the vehicle.

[0064] In one embodiment, a semiconductor light source may be arranged on the vehicle center side of the vehicle lamp with its optical axis facing outwards from the vehicle.

[0065] In one embodiment, the vehicle lighting fixture may further include an image sensor that, together with the lighting device, constitutes a gated camera.

[0066] 3. An illumination device for an active sensor according to one embodiment includes: a plurality of laser diodes; a plurality of light-collecting lenses, each disposed in the optical path of a corresponding emitted beam of the plurality of laser diodes, so that the emitted beam is nearly parallel; and a compound eye lens, which diffuses the emitted light from the plurality of light-collecting lenses.

[0067] According to this structure, by combining the light-collecting lens and the compound eye lens, appropriate light distribution can be formed, and the locally high brightness part in the light-emitting surface can be eliminated, thereby meeting the laser safety standards.

[0068] In one embodiment, multiple laser diodes may also be arranged in a horizontal direction.

[0069] In one embodiment, the plurality of light-collecting lenses may each have different focal lengths in the horizontal and vertical directions.

[0070] In one embodiment, multiple light-collecting lenses can also be integrally formed. This simplifies installation.

[0071] The preferred embodiments will now be described with reference to the accompanying drawings. The same or equivalent constituent elements, components, and processes shown in the various drawings are labeled with the same reference numerals, and repeated descriptions are omitted where appropriate. Furthermore, the embodiments are not intended to limit the disclosure or invention but are illustrative; not all features or combinations thereof described in the embodiments are essential parts of the disclosure or invention.

[0072] (Implementation Method 1)

[0073] Figure 1 This is a block diagram of the sensing system 10 according to Embodiment 1. The sensing system 10 is mounted on a vehicle such as a car or motorcycle to detect objects OBJ present around the vehicle.

[0074] The sensing system 10 mainly includes a gated camera 20. The gated camera 20 includes an illumination device 22, an image sensor 24, a camera controller 26, and an image processing device 28. The gated camera 20 captures images by dividing the field of view along the depth direction into multiple N (N≧2) ranges RNG1~RNG. N And so on. Adjacent ranges can overlap each other in the depth direction at their boundaries.

[0075] The illumination device (light emitter) 22 illuminates the front of the vehicle with illumination light L1 in sync with the light emission timing signal S1 supplied from the camera controller 26. In this embodiment, the illumination light L1 is near-infrared light or mid-infrared light.

[0076] Image sensor 24 includes multiple pixels and is capable of exposure control synchronized with the exposure timing signal S2 supplied from camera controller 26, generating a slice image IMG composed of multiple pixels. Image sensor 24 is sensitive to the same wavelength as the illumination light L1, and the reflected light (return light) L2 reflected by the object OBJ. For the i-th range RNG i The sliced ​​images IMG generated by the image sensor 24 are referred to as raw images or primary images as needed, to distinguish them from the final output of the gated camera 20, i.e., sliced ​​images IMGs.

[0077] For each range RNG, the camera controller 26 changes the emission timing signal S1 and the exposure timing signal S2, thereby varying the time difference between the emission of the illumination device 22 and the exposure of the image sensor 24. The emission timing signal S1 specifies the timing of the start of emission and the emission time. The exposure timing signal S2 specifies the timing of the start of exposure (the time difference with the emission) and the exposure time.

[0078] Gated camera 20 generates multiple ranges RNG1 to RNG N The corresponding multiple slice images IMG1~IMG N The i-th slice image IMG i In the middle, only the corresponding range of RNG is reflected. i The objects contained within.

[0079] The image processing device 28 can be implemented using a combination of a processor (hardware) such as a CPU (Central Processing Unit) or MPU (Micro Processing Unit), a microcomputer, or a GPU (Graphics Processing Unit), and a software program executed by the processor (hardware). The image processing device 28 can also be constructed entirely of hardware. The image processing device 28 processes the image generated by the image sensor 24 and outputs a final sliced ​​image. Furthermore, when the output of the image sensor 24 is directly used as the sliced ​​image, the image processing device 28 can be omitted.

[0080] Figure 2 This is a diagram illustrating the operation of the gated camera 20. Figure 2 The diagram shows the range of RNG for the i-th region. i The state is sensed as a Range of Interest (ROI). The illumination device 22 emits light synchronously with the emission timing signal S1 during the emission period τ1 between times t0 and t1. The top section shows a graph of light rays with time on the horizontal axis and distance on the vertical axis. The distance from the gated camera 20 to the range RNG is also shown. i Let d be the distance to the nearby boundary. MINi This will extend the range from the gated camera 20 to RNG. i Let the distance to the inner boundary be d. MAXi .

[0081] At a certain moment, the light emitted by the lighting device 22 reaches a distance d. MINi The round-trip time T of the reflected light returning to the image sensor 24 MINi for

[0082] T MINi =2×d MINi / c.

[0083] c is the speed of light.

[0084] Similarly, at a certain moment, the light emitted by the lighting device 22 reaches a distance d. MAXi The round-trip time T of the reflected light returning to the image sensor 24 MAXi for

[0085] T MAXi =2×d MAXi / c.

[0086] Within the scope of only needing to shoot RNG i When the included object OBJ is present, the camera controller 26 activates at time t2 = t0 + T. MINi Exposure begins at time t3 = t1 + T MAXi To end the exposure, an exposure timing signal S2 is generated. This completes one exposure cycle.

[0087] RNG shooting the i-th range i At this time, the illumination and exposure settings can be set and performed multiple times. The camera controller 26 can then repeat the illumination and exposure settings multiple times at a predetermined period τ2. The image sensor 24 outputs a slice image accumulated from the multiple exposures.

[0088] In this embodiment, in order to ensure that the exposure (brightness value of the object image within the slice image) is without deviation in each range, the gated camera 20 optimizes the shutter speed (exposure time), number of exposures, sensitivity, illumination intensity, and other (shooting parameters) for each range.

[0089] Figure 3 Figures (a) and (b) illustrate the images obtained by the gated camera 20. Figure 3 In example (a), there is an object (pedestrian) OBJ2 in range RNG2 and an object (vehicle) OBJ3 in range RNG3. Figure 3 In (b), it is shown that... Figure 3 Multiple slice images IMG1 to IMG3 were obtained under condition (a). When slice image IMG1 was captured, the image sensor was exposed only by the reflected light from range RNG1, so no object image was reflected in slice image IMG1.

[0090] When capturing slice image IMG2, the image sensor is exposed only by the reflected light from range RNG2, therefore only the object image OBJ2 is reflected in slice image IMG2. Similarly, when capturing slice image IMG3, the image sensor is exposed only by the reflected light from range RNG3, therefore only the object image OBJ3 is reflected in slice image IMG3. In this way, according to the gated camera 20, the object can be separated and captured in each range.

[0091] Next, the structure of the lighting device 22 will be described. Figure 4 This is a perspective view of a car 300 equipped with a gate camera 20. The car 300 includes left and right headlights 302L and 302R. In this embodiment, the lighting device 22 of the gate camera 20 is composed of lighting units 400L and 400R built into each of the left and right headlights 302L and 302R, and the emitted light from each lighting unit 400L and 400R is combined to form the illumination light distribution.

[0092] Figure 5 This diagram shows the structure of headlights 302L and 302R. In addition to the high beam / low beam light source 304 and the turn signal 306, headlight 302# also has a built-in lighting unit 400#.

[0093] The camera unit 308, corresponding to the image sensor 24 of the gate camera 20, is positioned to bring both the vehicle's driving lane and the oncoming lane into view. For example, the camera unit 308 is integrated into one of the headlights 302L and 302R (in this example, headlight 302R). Alternatively, for vehicles used in countries or regions that drive on the left, the camera unit 308 may be integrated into the right headlight 302R, and for vehicles used in countries or regions that drive on the right, the camera unit 308 may be integrated into the left headlight 302L.

[0094] Furthermore, the camera unit 308 can also be located outside the headlight 302. For example, the camera unit 308 can be configured inside the vehicle, such as in the position of the interior rearview mirror, or outside the vehicle, such as in the front grille (radiator grille).

[0095] Figure 6 This is an exploded perspective view of the headlight 302. The headlight 302 includes a high beam / low beam light source 304, a camera unit 308, an outer lens 310, an extension section 312, a lamp body 314, and a lamp unit 320. The lamp unit 320 is disposed inside the extension section 312. An opening 313 is provided in the extension section 312 such that the emitted light from the lamp unit 320 can pass through.

[0096] The lighting unit 320 includes a marker light (front position light) 330 as a white light and an illumination unit 400 for a gated camera, which are modularized.

[0097] Figure 7 This is a top view of the headlight 302R. In this example, the light guide 420's exit surface 422 is arranged obliquely relative to a surface orthogonal to the vehicle's direction of travel, following the shape of the headlight 302R. Inside the headlight 302, on the vehicle's outer side, a near-infrared light source 410 is positioned with its optical axis oriented towards the center of the vehicle.

[0098] Figure 8 This is an exploded perspective view of the lighting unit 320. The lighting unit 320 includes a lighting unit 400, a marker lamp 330, a printed circuit board 340, a heat sink 342, and a base 350. The lighting unit 320 has a right-side headlight 302R and a left-side headlight 302L with a left-right flipping structure.

[0099] The lighting unit 400 includes a near-infrared light source 410 and a light guide 420. The near-infrared light source 410 is a near-infrared semiconductor laser (laser diode). Alternatively, the near-infrared light source 410 can also be a high-output LED (light-emitting diode). The light guide 420 receives the emitted light, i.e., the near-infrared beam, from the near-infrared light source 410 at its light-incident surface 421, and emits the illumination light with a predetermined light distribution in front of the luminaire from its emission surface 422.

[0100] The marker light 330 includes a white light source 332 and a light guide 334. The white light source 332 is a white LED (light-emitting diode). The light guide 334 receives the emitted light from the white light source 332 at its end face. The white light is reflected inside the light guide 334 and emitted in front of the light fixture.

[0101] The light guide 420 of the lighting unit 400 has a back surface 424 opposite to the emission surface 422. The light guide 420 is configured such that the back surface 424 faces the light-emitting surface of the marker lamp 330, i.e., the surface 336 of the light guide 334. The light guide 420 emits the emitted light of the marker lamp 330 received at the back surface 424 from the emission surface 422 toward the front of the vehicle.

[0102] In this structure, the near-infrared light source 410 and the white light source 332 are mounted on a common printed circuit board 340. Furthermore, a heat sink 342 is mounted on the printed circuit board 340.

[0103] Figure 9 (a) is a perspective view of the lighting unit 400. Figure 9 (b) is a top view of the lighting unit 400.

[0104] On the back surface 424 of the light guide 420, a plurality of steps 426 are provided, separated along the optical axis of the near-infrared light source 410. The steps 426 are formed at an angle relative to the optical axis. The angle of each step 426 is designed such that the light reflected from its surface is directed towards the vehicle's forward direction. Furthermore, to improve reflectivity, a metal such as aluminum can be vapor-deposited onto the steps 426. Additionally, the portion of the back surface 424 other than the steps 426 is substantially parallel to the optical axis. The emitted light L1 from the near-infrared light source 410 is transmitted along the optical axis (X direction in the figure) inside the light guide 420, reflected in the steps 426 on the back surface 424, and emitted from the emission surface 422 in a direction forward of the lamp (Z direction). Figure 9 In (b), a representative ray of the infrared beam emitted from the near-infrared source 410 is shown by a single-dotted line. Furthermore, in Figure 9 In (b), the emitted light L3 of the outline lamp 330 on the back of the light guide 420 is shown by a dashed line.

[0105] The above describes the structure of the headlight 302. According to this headlight 302, the optical system of the illumination device of the gated camera, which is composed of the light guide 420, increases the freedom of shape and size of the illumination unit 400 compared to the case of using a lens optical system or a reflective optical system, without impairing the function of the existing lamp, and can be accommodated in the headlight housing.

[0106] Furthermore, when a light guide transmits white light, it is perceived as emitting white light due to internal reflection or scattering. Therefore, while light guides have historically been used as marker lights, they are difficult to employ in lights intended for illuminating objects, as they are used for low beams or high beams. In this respect, in this embodiment, by setting the illumination light for the active sensor to infrared light, even when a light guide is used in the optical system for forming the illumination light, it will not be perceived as emitting white light.

[0107] In addition, according to the headlight 302, by arranging the marker lamp 330 behind the illumination unit 400 that generates near-infrared illumination light, the near-infrared spectral components contained in the illumination light overlap with the white light emitted by the marker lamp 330, thereby preventing it from being perceived as red.

[0108] Furthermore, by utilizing the reflection of multiple steps 426 disposed on the light guide 420, a light distribution is formed, which can be formed to extend in the horizontal direction and cover the entire horizontal field of view of the image sensor.

[0109] Figure 10 (a) and (b) are diagrams showing the simulation results of the light distribution pattern of the lighting unit 400 of Embodiment 1. Figure 10 (a) shows the luminance distribution on an imaginary vertical screen. Figure 10(b) shows the luminance distribution in the vertical direction. In this structure, the range of ±10° in the horizontal direction and ±7° in the vertical direction is the half-value width of the illumination light.

[0110] Reference Figure 10 In (b), two peaks appear in the vertical direction in this light distribution. Figure 11 Figures (a) and (b) illustrate the cause of the generation of multiple peaks within the light distribution. The inventors of this invention recognized that one cause of the generation of multiple peaks is reflection from the upper or lower surface within the light guide 420. Several variations for improving the luminous intensity distribution in the vertical direction are described below.

[0111] (Variation Example 1)

[0112] Figure 12 Figures (a) and (b) illustrate the light guide 420A of Modified Example 1. In this Modified Example 1, the sagittal plane (Y-Z section) of the light guide 420A faces forward of the vehicle and is inverted conical in shape, with the distance between the upper surface 428 and the bottom surface 429 increasing as it faces forward of the vehicle (Feature 1). Furthermore, the exiting surface 422 of the light guide 420A has curvature in the vertical direction (Feature 2). In this example, the exiting surface 422 has positive curvature.

[0113] exist Figure 12 In (b), the optical path in the light guide 420A is shown. By setting it to an inverted cone shape, reflections at the upper surface 428 and the bottom surface 429 of the light guide 420A are suppressed. When the cone angle of the light guide 420A is greater than the vertical expansion angle of the infrared beam, theoretically, reflections at the upper surface 428 and the bottom surface 429 can be eliminated. Furthermore, the present invention is not limited to this; the cone angle can also be smaller than the beam expansion angle, and even in this case, the effect of suppressing the generation of multiple peaks can be obtained.

[0114] Furthermore, according to Modified Example 1, the vertical extension angle of the emitted illumination light, i.e. the illumination range, can be controlled according to the curvature of the emitting surface 422 of the light guide 420A.

[0115] Figure 13 (a) and (b) are diagrams showing the simulation results of the light distribution pattern when using the light guide of modified example 1. Figure 13 (a) shows the luminance distribution on an imaginary vertical screen. Figure 13 (b) shows the luminance distribution in the vertical direction. For example... Figure 13 As shown in (b), according to Modification 1, the luminance distribution in the vertical direction can be made into a single peak. This is the effect of making the light guide 420A into an inverted cone shape.

[0116] Furthermore, in modified example 1, the vertical irradiation range is ±4°. This is the effect of imparting curvature (R = 300 mm) to the exit surface 422.

[0117] (Variation Example 2)

[0118] Figure 14 Figures (a) and (b) illustrate the light guide 420B of Modified Example 2. In this modified example, absorbing materials 430 and 432 (feature 3) are attached to at least one of the upper surface 428 and the bottom surface 429 of the light guide 420B (both in this example). Higher absorption rates of the absorbing materials 430 and 432 are preferred, preferably 90% or higher. The absorbing materials 430 and 432 are materials that absorb near-infrared light beams in the wavelength range, and their types are not limited.

[0119] Figure 15 This is a diagram showing the simulation results of the vertical light distribution in Modified Example 2. For comparison, the light distribution without absorbing material is shown. Without absorbing material, the light distribution is divided into three peaks. In contrast, by attaching absorbing material, the reflected light at the upper surface 428 and bottom surface 429 of the light guide 420B can be reduced, suppressing the generation of multiple peaks.

[0120] (Variation Example 3)

[0121] Figure 16 Figures (a) and (b) illustrate the light guide 420C of Modified Example 3. In this modified example, the light-incident surface 421 of the light guide 420C has curvature (feature 4) in the horizontal direction. In this example, the light-incident surface 421 is convex, so that the emitted light beam with an extension angle is close to parallel light.

[0122] As shown by the dashed line, if there is an extended infrared beam guide inside the light guide 420, it will be totally reflected at the exit surface 422, resulting in reduced efficiency, diffuse light, and halo. To address this, by making the infrared beam nearly parallel, total reflection at the exit surface 422 can be suppressed, thereby reducing efficiency or suppressing diffuse light and halo.

[0123] Alternatively, the horizontal light distribution of the illumination light emitted from the exit surface 422 of the light guide 420C can be controlled according to the curvature of the incident surface 421.

[0124] (Variation Example 4)

[0125] Figure 17 This is a diagram showing the light guide 420D of Modified Example 4. In this modified example, the light-incident surface 421 of the light guide 420D has curvature in the vertical direction (feature 5). In this example, the light-incident surface 421 is convex, so that the emitted light beam with an extension angle is close to parallel light.

[0126] Therefore, the vertical light distribution of the illumination light emitted from the exit surface 422 of the light guide 420D can be controlled according to the curvature of the incident surface. In addition, since the horizontal spread of the infrared light after reflection at the step 426 is suppressed, incident light onto the upper and lower surfaces of the light guide can be suppressed.

[0127] Furthermore, features 1 to 5 described in variations 1 to 4 can be combined arbitrarily.

[0128] The present invention has been described above based on embodiments. These embodiments are illustrative, and those skilled in the art should understand that various modifications can be formed by combining the constituent elements or processing procedures, and such modifications are also included within the scope of the present invention. These modifications will now be described.

[0129] In this embodiment, an illumination device for a gate-controlled camera has been described, but the application of the present invention is not limited thereto and can be applied to illumination devices for various active sensors.

[0130] In this embodiment, the light guide of the lighting unit 400 is positioned in front of the parking lights 330. However, the type of white light source is not limited to the parking lights 330; it can be positioned in front of the low beam headlights, ADB (Adaptive Driving Beam) headlights, or Daytime Running Lamps (DRL). Furthermore, if the light guide is not considered red, the lighting unit 400 can be positioned in a location unrelated to the white light source.

[0131] Figure 18 (a) and (b) are schematic front views illustrating the layout of the lighting unit 400. Figure 18 In (a), inside the headlight 302 on the outer side of the vehicle, the near-infrared light source 410 is configured with its optical axis oriented toward the center of the vehicle. Figure 18 In (b), the near-infrared light source 410 is configured with its optical axis facing outwards from the vehicle, inside the headlight 302 on the vehicle center side.

[0132] (Implementation Method 2)

[0133] In Embodiment 2, other structures of the lighting unit will be described.

[0134] Lighting unit 400 corresponds to Figure 1 The lighting device 22. In Embodiment 1, the illumination light emitted by the lighting unit 400 is near-infrared light or mid-infrared light, but in Embodiment 2, it may also be visible light with a specified wavelength.

[0135] Figure 19This is an exploded perspective view of the headlight 302 according to Embodiment 2. The headlight 302 includes a high beam / low beam light source 304, a camera unit 308, an outer lens 310, an extension portion 312, a lamp body 314, and an illumination unit 400. The illumination unit 400 is disposed inside the extension portion 312. An opening 313 is provided in the extension portion 312 such that the emitted light from the illumination unit 400 can pass through. The position of the illumination unit 400 is not particularly limited, but it can be disposed, for example, below the headlight 302.

[0136] Figure 20 This is an exploded perspective view of the illumination unit 400. The illumination unit 400 includes multiple laser diodes 402_1 to 402_N, a heat sink 404, a housing 406, multiple light-collecting lenses 440_1 to 440_N, and a compound eye lens 450. In this example, N = 6.

[0137] Multiple laser diodes 402_1 to 402_N are arranged horizontally (X direction in the figure). Each laser diode 402 emits an outgoing beam with a certain spread angle.

[0138] The heat sink 404 supports multiple laser diodes 402 from the inside. The heat sink 404 is thermally coupled to the laser diodes 402, and the heat of the laser diodes 402 is diffused and emitted through the heat sink 404.

[0139] Multiple light-collecting lenses 440_1 to 440_N are arranged correspondingly to multiple laser diodes 402_1 to 402_N. Each light-collecting lens 440_i (1≦i≦N) is positioned in the optical path of the emitted beam of one of the laser diodes 402_i, so that the emitted beam is emitted in a nearly parallel manner.

[0140] Each light-collecting lens 440 has a different focal distance in the horizontal direction (X direction) and the vertical direction (Y direction). Multiple light-collecting lenses 440_1 to 440_N are integrally formed as a lens unit 409.

[0141] Figure 21 Figure (a) shows an example of the configuration of the light-collecting lens 440. The light-collecting lens 440 is constructed by bonding two cylindrical lenses 440a and 440b that are orthogonal in the refractive (power) direction. The cylindrical lens 440a on the laser diode 402 side, which serves as the light source, has the refractive direction in the horizontal direction (X direction), while the cylindrical lens 440b on the exit surface side has the refractive direction in the vertical direction (Y direction).

[0142] return Figure 20 The compound eye lens 450 diffuses the outgoing light from the multiple light-collecting lenses 440_1 to 440_N. Figure 21(b) is a three-dimensional view of the compound eye lens 450. The compound eye lens 450, also known as a diffuse illumination element, is an imaging element in which identical single lenses 452 are arranged in a matrix.

[0143] Figure 22 (a) is a cross-sectional view of the lighting unit 400. Figure 22 (b) is a perspective view of the lighting unit 400.

[0144] The housing 406 has two openings on opposite sides. A heat sink 404 is fixed on one opening side, and a lens unit 409 and a compound eye lens 450 are fixed on the other opening side.

[0145] The above describes the structure of the lighting unit 400. Its operation will now be explained. Figure 23 (a) and (b) are the light diagrams of the lighting unit 400. Figure 23 (a) is the ray diagram in the X-Z plane. Figure 23 (b) is the ray diagram in the Y-Z plane. For example... Figure 23 As shown in (a), the light-collecting lens 440 has a first focal power relative to the horizontal direction, and the emitted beam of the laser diode 402 is nearly parallel to the horizontal direction. The emitted light of the compound eye lens 450 radiates within an angular range of ±θ (°) relative to the horizontal direction.

[0146] like Figure 23 As shown in (b), the light-collecting lens 440 has a second focal power relative to the vertical direction, and the emitted beam from the laser diode 402 is also nearly parallel relative to the vertical direction. The emitted beam from the compound eye lens 450 is directed towards the vertical direction. Radiation within an angular range.

[0147] The horizontal expansion angle θ can be designed using parameters such as the first focal length (focal distance) of the light-collecting lens 440, the distance between the laser diode 402 and the light-collecting lens 440, and the focal length (focal distance) of the single lens 452 constituting the compound eye lens 450. Similarly, the vertical expansion angle... The second focal length of the light-collecting lens 440, the distance between the laser diode 402 and the light-collecting lens 440, and the focal length of the single lens 452 constituting the compound eye lens 450 can be used as parameters for design.

[0148] Figure 24 This is a graph showing the brightness distribution (simulation results) of the emitted beam from the illumination unit 400. In this example, a beam with a horizontal direction θ = ±17° and a vertical direction... of lighting.

[0149] According to the illumination unit 400, a suitable light distribution can be formed by combining a light-collecting lens and a compound eye lens. Furthermore, locally high-brightness portions within the emitting surface can be removed, thus meeting laser safety standards. Specifically, the illumination unit 400 is classified as laser class 1, requiring an achievable radiation dose (AE) to achievable radiation limit (AEL) ratio (AE / AEL) of less than 1; however, according to this embodiment, laser safety standards for laser class 1 are met.

[0150] According to the embodiments, the present invention has been described using specific statements. However, the embodiments only show one aspect of the principle and application of the present invention. Various modifications or configuration changes are allowed for the embodiments without departing from the spirit of the present invention as defined in the claims.

[0151] Industrial availability

[0152] This disclosure can be used in active sensors.

[0153] Explanation of reference numerals in the attached figures

[0154] S1 LED timing signal

[0155] S2 Exposure Timing Signal

[0156] 10-sensor system

[0157] 20 gated cameras

[0158] 22 lighting fixtures

[0159] 24 image sensors

[0160] 26 Camera Controller

[0161] 28 Image Processing Devices

[0162] 300 Cars

[0163] 302 headlight

[0164] 304 High Beam / Low Beam Light Source

[0165] 306 Turn Signal

[0166] 308 camera unit

[0167] 310 external lens

[0168] 312 Extension Section

[0169] 314 lamp body

[0170] 320 lighting unit

[0171] 330 side marker lights

[0172] 332 white light source

[0173] 334 light guide

[0174] 340 printed substrate

[0175] 342 Radiator

[0176] 350 substrate

[0177] 400 lighting units

[0178] 402 laser diode

[0179] 404 heatsink

[0180] 406 housing

[0181] 410 Near Infrared Light Source

[0182] 420 light guide

[0183] 422 exit surface

[0184] 424 back

[0185] 426 steps

[0186] 428 upper surface

[0187] 429 bottom

[0188] 440 light-gathering lens

[0189] 450 compound eye lens

[0190] 452 Single Lens

Claims

1. A vehicle lamp characterized by comprising: Comprise: a white lamp, and an illumination device for an active sensor; the illumination device comprises: a near-infrared light source, and a first light guide that receives emergent light of the near-infrared light source and emits illumination light having a prescribed light distribution from an emission surface; the white lamp comprises: a white light source, and a second light guide that guides white light of the white light source and is different from the first light guide; the white light source and the near-infrared light source are mounted on the same substrate, the first light guide is disposed with its back surface opposite a light-emitting surface of the second light guide, and emits emergent light from the emission surface that is received by the back surface from the second light guide, a plurality of steps are provided on the back surface in a direction of an optical axis of the near-infrared light source, the plurality of steps are provided on an entire long-axis-direction surface of the back surface, and each of the plurality of steps is formed to be inclined with respect to the direction of the optical axis, and the emergent light of the near-infrared light source is reflected in the steps and emitted from the emission surface.

2. The vehicle lamp according to claim 1, wherein the white lamp is a clearance lamp.

3. The vehicle lamp according to claim 1, further comprising an image sensor that constitutes a gated camera together with the illumination device.

4. A vehicle lamp comprising: an illumination device for an active sensor, the illumination device comprising: a semiconductor light source that emits an infrared light beam; and a light guide that receives the infrared light beam at an incident surface and emits illumination light having a prescribed light distribution from an emission surface, a plurality of steps are provided on a back surface of the light guide in a direction of an optical axis of the semiconductor light source, the plurality of steps are provided on an entire long-axis-direction surface of the back surface, and each of the plurality of steps is formed to be inclined with respect to the direction of the optical axis, and the emergent light of the semiconductor light source is reflected in the steps and emitted from the emission surface.

5. The vehicle lamp according to claim 4, wherein the emission surface of the light guide has a curvature in a vertical direction.

6. The vehicle lamp according to claim 4, wherein a sagittal plane of the light guide is inverted conical toward a front of the vehicle.

7. The vehicle lamp according to claim 4, further comprising an absorbing material that is attached to at least one of an upper surface and a bottom surface of the light guide and absorbs the infrared light beam.

8. The vehicle lamp according to claim 4, wherein the incident surface of the light guide has a curvature in a horizontal direction.

9. The vehicle lamp according to claim 4, wherein the semiconductor light source is disposed with its optical axis toward a center of the vehicle on a vehicle-outer side in the vehicle lamp.

10. The vehicle lamp according to claim 4, wherein the semiconductor light source is disposed with its optical axis toward a vehicle-outer side on a vehicle-center side in the vehicle lamp.

11. The vehicle lamp according to claim 4, further comprising an image sensor that constitutes a gated camera together with the illumination device.

Images