Vehicle lighting fixtures, lighting devices for active sensors, gating cameras

Abstract

This vehicle lamp comprises: a clearance lamp (330); and an illumination unit (400) for an active sensor. The illumination unit (400) comprises a near-infrared light source (410) and a light guide body (420). The light guide body (420) receives light emitted from the near-infrared light source (410) and emits illumination light having a prescribed light distribution from an emitting surface (422). The light guide body (420) is disposed so that a back surface (424) thereof faces a light-emitting surface of the clearance lamp (330), and receives, on the back surface (424), the light emitted from the clearance lamp (330) and emits such light from the emitting surface (422).

Description

[Technical field]

[0001] The present invention relates to active sensors. [Background technology]

[0002] For autonomous driving and automatic control of headlamp distribution, an object identification system is used to sense the position and type of objects around the vehicle. The object identification system includes a sensor and a processing unit that analyzes the sensor output. The sensor is selected from cameras, LiDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging), millimeter wave radar, ultrasonic sonar, active sensors, etc., taking into consideration the application, required accuracy, and cost.

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

[0004] A TOF camera is known as a camera that can obtain depth information. A TOF (Time Of Flight) camera projects infrared light using a light-emitting device, measures the flight time it takes for the reflected light to return to an image sensor, and obtains a TOF image in which the flight time is converted into distance information.

[0005] As an active sensor to replace the TOF camera, a gating camera is A gated camera has been proposed (Patent Documents 1 and 2). A gating camera divides the shooting range into multiple ranges, and captures images by changing the exposure timing and exposure time for each range. This allows slice images to be obtained for each target range, and each slice image contains only objects that are included in the corresponding range. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2009-257983 A [Patent Document 2] International Publication WO2017 / 110413A1 Summary of the Invention [Problem to be solved by the invention]

[0007] 1. When using near-infrared light as the lighting device for an active sensor, part of the spectrum is perceived as red by the human eye, so installing it in a headlamp without taking measures against this violates regulations.

[0008] An aspect of the present disclosure has been made in this context, and one exemplary purpose of the disclosure is to provide a vehicular lamp that satisfies regulations.

[0009] 2. The present inventors have considered incorporating an active sensor lighting device into a vehicle lamp.

[0010] Vehicle lighting fixtures include existing low beam, high beam, position lamps (clearance lamps), and turn signals. Illumination devices for active sensors are required to have a light distribution that covers the field of view of the image sensor of the active sensor, but they must be positioned so as not to impair the functionality of existing lamps, which places restrictions on size and shape.

[0011] An aspect of the present disclosure has been made in light of such a situation, and one of its exemplary purposes is to provide a vehicle lamp incorporating an illumination device for an active sensor.

[0012] When a laser diode is used as an illumination device for an active sensor, it is necessary to satisfy laser safety standards while forming an appropriate light distribution in the field of view.

[0013] An aspect of the present disclosure has been made in light of such a situation, and one of its exemplary purposes is to provide a lighting device that can achieve both appropriate light distribution and laser safety standards. [Means for solving the problem]

[0014] 1. A vehicle lamp according to an embodiment of the present 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 light emitted from the near-infrared light source and emits illumination light having a predetermined light distribution from an emission surface. The light guide is disposed so that its back surface faces the light emitting surface of the white lamp, and emits the emitted light of the white lamp received on its back surface from the emission surface.

[0015] 2. A vehicle lamp according to an embodiment of the present disclosure includes a lighting device for an active sensor, the lighting device including a semiconductor light source that emits an infrared light beam, and a light guide that receives the infrared light beam at a light entrance surface and emits illumination light having a predetermined light distribution from an exit surface.

[0016] 3. An illumination device for an active sensor according to one aspect of the present disclosure includes a plurality of laser diodes, a plurality of focusing lenses, each of which is disposed on the optical path of a corresponding one of the emission beams of the plurality of laser diodes and which converts the emission beam into a parallel beam, and a fly's eye lens which diffuses the emission beams of the plurality of focusing lenses. Effect of the Invention

[0017] According to an aspect of the present disclosure, it is possible to satisfy regulations. According to an aspect of the present disclosure, it is possible to provide a vehicle lamp having a built-in lighting device for an active sensor. According to an aspect of the present disclosure, it is possible to achieve both appropriate light distribution and laser safety standards. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a block diagram of a sensing system according to a first embodiment. [Diagram 2] FIG. 2 is a diagram illustrating the operation of a gating camera. [Diagram 3] 3(a) and (b) are diagrams illustrating images obtained by the gating camera. [Figure 4] FIG. 1 is a perspective view of a car equipped with a gating camera. [Diagram 5] FIG. 2 is a diagram showing the configuration of a headlamp. [Figure 6] FIG. 1 is an exploded perspective view of a headlamp according to a first embodiment. [Figure 7] FIG. 7 is a plan view of the headlamp of FIG. 6. [Figure 8] FIG. [Figure 9] FIG. 9(a) is a perspective view of the lighting unit, and FIG. 9(b) is a plan view of the lighting unit. [Figure 10] 10(a) and (b) are diagrams showing simulation results of the light distribution pattern of the lighting unit according to the first embodiment. [Figure 11] 11(a) and 11(b) are diagrams for explaining the cause of occurrence of multiple peaks in the light distribution. [Figure 12] 12(a) and (b) are diagrams showing a light guide according to the first modification. [Figure 13] 13(a) and (b) are diagrams showing the simulation results of a light distribution pattern when a light guide according to the first modification is used. [Figure 14] 14(a) and (b) are diagrams showing a light guide according to the second modification. [Figure 15] 15(a) and (b) are diagrams showing the simulation results of the light amount distribution in the vertical direction in the second modification. [Figure 16] 16(a) and (b) are diagrams showing a light guide according to the third modification. [Figure 17] FIG. 13 is a diagram showing a light guide according to a fourth modified example. [Figure 18] 18(a) and (b) are front views showing a schematic layout of the lighting unit. [Figure 19] FIG. 11 is an exploded perspective view of a headlamp according to a second embodiment. [Figure 20]FIG. 20 is an exploded perspective view of the lighting unit of FIG. 19. [Figure 21] FIG. 21(a) is a diagram showing an example of the configuration of a condenser lens, and FIG. 21(b) is a perspective view of a fly's eye lens. [Figure 22] FIG. 22(a) is a cross-sectional view of the lighting unit, and FIG. 22(b) is a perspective view of the exterior of the lighting unit. [Figure 23] 23(a) and (b) are ray diagrams of the lighting unit. [Figure 24] FIG. 11 is a diagram showing the luminance distribution (simulation results) of the output beam of the lighting unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] A summary of some exemplary embodiments of the present disclosure will be described. This summary is intended to provide a simplified overview of some concepts of one or more embodiments for a basic understanding of the embodiments as a prelude to the detailed description that follows, and is not intended to limit the scope of the invention or disclosure. This summary is not intended to be an exhaustive overview of all possible embodiments, nor is it intended to identify key elements of all embodiments or to delineate the scope of some or all aspects. For convenience, the term "one embodiment" may be used to refer to one embodiment (example or variant) or multiple embodiments (examples or variants) disclosed in this specification.

[0020] 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 light emitted from the near-infrared light source and emits illumination light having a predetermined light distribution from an emission surface. The light guide is disposed so that its back surface faces the light emitting surface of the white lamp, and emits the emitted light of the white lamp received on its back surface from the emission surface.

[0021] According to this configuration, the near-infrared light is emitted while overlapping with the white light, so that it is possible to prevent the light from being visually perceived as red, thereby complying with regulations.

[0022] In one embodiment, the white lamp may be a clearance lamp, which plays an important role in creating an impression of the design of a headlamp, and by arranging the clearance lamp and the active sensor member so as to overlap each other, it is possible to add the illumination function of the active sensor without impairing the design of the headlamp.

[0023] In one embodiment, the back surface of the light guide may be provided with a number of steps spaced apart along the optical axis of the near infrared light source.

[0024] In one embodiment, the white lamp may include a white light source and a light guide that guides the white light of the white light source. The white light source and the near-infrared light source may be mounted on the same board. This allows the white light source, the near-infrared light source, and their driving circuits to be integrated in one location within the headlamp.

[0025] In one embodiment, the lighting device and the white lamp may be modularized.

[0026] 2. A vehicle lamp according to one embodiment includes a lighting device for an active sensor. The lighting device includes a semiconductor light source that emits an infrared light beam, and a light guide that receives the infrared light beam at a light entrance surface and emits illumination light having a predetermined light distribution from an exit surface.

[0027] The use of a light guide offers greater freedom in the shape and size of the lighting device compared to using a lens optical system or a reflective optical system, making it possible to accommodate the lighting device within the headlamp housing without compromising the functionality of the existing lamp.

[0028] When white light is transmitted through a light guide, the light guide itself glows white due to internal reflection and diffusion. Therefore, while light guides have been used in lamps intended to be visible from the outside, such as clearance lamps, it has been difficult to adopt them in lamps intended to illuminate objects, such as low beams and high beams. In this regard, by using infrared light as the illumination light for the active sensor, even if a light guide is used in an optical system for forming the light distribution of the illumination light, it will not be visible as glowing white.

[0029] In one embodiment, the back surface of the light guide may be provided with a plurality of steps (reflection patterns) spaced apart in the optical axis direction of the semiconductor light source. By utilizing reflections from the plurality of steps, a horizontally spreading light distribution of illumination light can be formed in front of the vehicle, covering the entire horizontal field of view of the image sensor.

[0030] In one embodiment, the exit surface of the light guide may have a curvature in the vertical direction, whereby the vertical light distribution of the illumination light exiting from the exit surface of the light guide can be controlled according to the curvature.

[0031] In one embodiment, the sagittal plane of the light guide may be inversely tapered toward the front of the vehicle. When an infrared beam is reflected on the top and bottom surfaces of the light guide, the luminous intensity distribution of the light distribution has multiple peaks in the vertical direction. By providing the inverse taper, the reflection on the top and bottom surfaces of the light guide can be suppressed, and the occurrence of multiple peaks can be suppressed.

[0032] In one embodiment, the light guide may further include an absorber attached to at least one of the top and bottom surfaces of the light guide to absorb the infrared light beam, thereby reducing the reflected light on the top and bottom surfaces of the light guide and suppressing the occurrence of multiple peaks.

[0033] In one embodiment, the light-entering surface of the light guide may have a curvature in the horizontal direction. The curvature can be designed so that the infrared beam inside the light guide approaches parallel light (collimated light), thereby preventing the infrared beam from being totally reflected at the exit surface of the light guide. Alternatively, the horizontal light distribution of the illumination light emitted from the exit surface of the light guide can be controlled according to the curvature of the light-entering surface.

[0034] In one embodiment, the semiconductor light source may be disposed in a vehicle lamp on the outer side of the vehicle, with its optical axis directed toward the center of the vehicle.

[0035] In one embodiment, the semiconductor light source may be disposed in a vehicle lamp toward the center of the vehicle, with its optical axis facing outward from the vehicle.

[0036] In one embodiment, the vehicle lamp may further include an image sensor that, together with the lighting device, constitutes a gating camera.

[0037] 3. An illumination device for an active sensor according to one embodiment includes a plurality of laser diodes, a plurality of focusing lenses, each of which is disposed on the optical path of a corresponding one of the emission beams of the plurality of laser diodes and which converts the emission beam into a parallel beam, and a fly-eye lens which diffuses the emission beams of the plurality of focusing lenses.

[0038] According to this configuration, the combination of the focusing lens and the fly's eye lens can form an appropriate light distribution while eliminating areas with locally high brightness within the light emitting surface, thereby satisfying laser safety standards.

[0039] In one embodiment, multiple laser diodes may be arranged side-by-side in a horizontal direction.

[0040] In one embodiment, each of the multiple focusing lenses may have different powers in the horizontal and vertical directions.

[0041] In one embodiment, the multiple focusing lenses may be integrally formed, which allows for ease of assembly.

[0042] Hereinafter, preferred embodiments will be described with reference to the drawings. The same or equivalent components, parts, and processes shown in each drawing will be given the same reference numerals, and duplicated descriptions will be omitted as appropriate. In addition, the embodiments are illustrative and do not limit the disclosure and invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the disclosure and invention.

[0043] (Embodiment 1) 1 is a block diagram of a sensing system 10 according to embodiment 1. The sensing system 10 is mounted on a vehicle such as an automobile or motorcycle, and detects an object OBJ that exists around the vehicle.

[0044] The sensing system 10 mainly includes a gating camera 20. The gating camera 20 includes an illumination device 22, an image sensor 24, a camera controller 26, and an image processing device 28. The imaging by the gating camera 20 is performed by dividing the field of view into a plurality of ranges RNG (N≧2) in the depth direction. 1 ~RNG N Adjacent ranges may overlap in the depth direction at their boundaries.

[0045] The lighting device (floodlight) 22 irradiates the illumination light L1 ahead of the vehicle in synchronization with a light emission timing signal S1 provided from the camera controller 26. In this embodiment, the illumination light L1 is near-infrared light or mid-infrared light.

[0046] The image sensor 24 includes a plurality of pixels, and is capable of controlling exposure in synchronization with an exposure timing signal S2 provided by the camera controller 26, thereby generating a slice image IMG consisting of a plurality of pixels. The image sensor 24 is sensitive to the same wavelength as the illumination light L1, and captures the reflected light (return light) L2 reflected by the object OBJ. The i-th range RNG iThe slice images IMG generated by the image sensor 24 in this regard are referred to as raw images or primary images, as necessary, to be distinguished from the slice images IMGs that are the final output of the gating camera 20.

[0047] The camera controller 26 changes the light emission timing signal S1 and the exposure timing signal S2 for each range RNG to change the time difference between the light emission by the lighting device 22 and the exposure of the image sensor 24. The light emission timing signal S1 specifies the timing to start light emission and the light emission time. The exposure timing signal S2 specifies the timing to start exposure (the time difference with light emission) and the exposure time.

[0048] The gating camera 20 has multiple range RNGs. 1 ~RNG N Multiple slice images IMG corresponding to 1 ~IMG N The i-th slice image IMG i has a corresponding range RNG i Only objects contained within will be captured.

[0049] The image processing device 28 can be implemented by combining a processor (hardware) such as a CPU (Central Processing Unit), MPU (Micro Processing Unit), microcomputer, or GPU (Graphics Processing Unit) with a software program executed by the processor (hardware). The image processing device 28 may be configured only with hardware. The image processing device 28 processes the image generated by the image sensor 24 and outputs a final slice image. Note that when the output of the image sensor 24 is used as the slice image as it is, the image processing device 28 can be omitted.

[0050] FIG. 2 is a diagram for explaining the operation of the gating camera 20. In FIG. 2, the i-th range RNG i When sensing the range of interest (ROI), The lighting device 22 is synchronized with the light emission timing signal S1 at a time t 0 ~t 1 The light emission period τ 1 The top row shows a diagram of a light beam with time on the horizontal axis and distance on the vertical axis. i The distance to the boundary in front of MINi、 Range RNG i The distance to the inner boundary of MAXi Let us assume that.

[0051] Light that leaves the lighting device 22 at a certain time travels a distance d MINi The round trip time T MINi teeth, T MINi =2×d MINi / c where c is the speed of light.

[0052] Similarly, light that leaves the lighting device 22 at a certain time travels a distance d MAXi The round trip time T MAXi teeth, T MAXi =2×d MAXi / c It is.

[0053] Range RNG i When it is desired to photograph only the object OBJ included in the image, the camera controller 26 2 =t 0 +T MINi Exposure begins at time t 3 =t 1 +T MAXi The exposure timing signal S2 is generated so as to end the exposure at the specified timing. This is one exposure operation.

[0054] i-th range RNG i When capturing an image, multiple sets of light emission and exposure may be performed. In this case, the camera controller 26 controls the camera 26 to perform multiple sets of light emission and exposure at a predetermined period τ 2Then, the above-mentioned set of irradiation and exposure operations may be repeated a number of times. The image sensor 24 outputs slice images accumulated by the multiple exposures.

[0055] In this embodiment, in order to prevent the exposure (brightness value of the object image in the slice image) from varying for each range, the gating camera 20 optimizes the shutter speed (exposure time), number of exposures, sensitivity, illumination light intensity, etc. (shooting parameters) for each range.

[0056] 3(a) and (b) are diagrams illustrating images obtained by the gating camera 20. In the example of FIG. 3(a), the range RNG 2 Object (pedestrian) OBJ 2 There is a range RNG 3 Object (vehicle) OBJ 3 FIG. 3(b) shows a plurality of slice images IMG obtained in the situation shown in FIG. 3(a). 1 ~IMG 3 is shown. Slice image IMG 1 When taking a picture, the image sensor uses the range RNG 1 Since the slice image IMG 1 No object image is captured on the screen.

[0057] Slice image IMG 2 When taking a picture, the image sensor uses the range RNG 2 Since the slice image IMG 2 Object image OBJ 2 Similarly, only the slice image IMG 3 When taking a picture, the image sensor uses the range RNG 3 Since the slice image IMG 3 Object image OBJ 3 In this way, the gating camera 20 can capture an image of an object separately for each range.

[0058] Next, the configuration of the lighting device 22 will be described. Fig. 4 is a perspective view of an automobile 300 equipped with a gating camera 20. The automobile 300 is equipped with left and right headlamps 302L, 302R. In this embodiment, the lighting device 22 of the gating camera 20 includes lighting units 400L, 400R built into the left and right headlamps 302L, 302R, respectively. The light emitted from each of the lighting units 400L and 400R is combined to provide illumination. A bright light distribution is formed.

[0059] 5 is a diagram showing the configuration of headlamps 302L, 302R. Headlamp 302# (#=L, R) has high beam / low beam light source 304, turn signal lamp 306, and lighting unit 400# built in.

[0060] The camera unit 308 corresponding to the image sensor 24 of the gating camera 20 is disposed at a position where both the lane in which the vehicle is traveling and the oncoming lane can be viewed. For example, the camera unit 308 is built into one of the headlamps 302L, 302R (headlamp 302R in this example). For vehicles used in countries or regions where traffic is on the left, the camera unit 308 may be built into the right headlamp 302R, and for vehicles used in countries or regions where traffic is on the right, the camera unit 308 may be built into the left headlamp 302L.

[0061] Camera unit 308 may be provided outside headlamp 302. For example, camera unit 308 may be disposed inside the vehicle cabin, for example at the position of the rearview mirror, or outside the vehicle cabin, for example at the front grill (radiator grill).

[0062] 6 is an exploded perspective view of a headlamp 302. The headlamp 302 includes a high beam / low beam light source 304, a camera unit 308, an outer lens 310, an extension 312, a lamp body 314, and a lamp unit 320. The lamp unit 320 is provided on the back side of the extension 312. An opening 313 is provided in the extension 312 so that light emitted from the lamp unit 320 can pass through.

[0063] The lighting unit 320 includes a clearance lamp (front position lamp) 320, which is a white lamp, and an illumination unit 400 for the gating camera, and is modularized.

[0064] 7 is a plan view of the headlamp 302R. In this example, the emission surface 422 of the light guide 420 follows the shape of the headlamp 302R, and the light guide 420 is disposed tilted with respect to a plane perpendicular to the traveling direction of the vehicle. The near-infrared light source 410 is disposed inside the headlamp 302 on the outside of the vehicle, with its optical axis directed toward the center of the vehicle.

[0065] 8 is an exploded perspective view of the lamp unit 320. The lamp unit 320 includes an illumination unit 400, a clearance lamp 330, a printed circuit board 340, a heat sink 342, and a base 350. This lamp unit 320 is for the right headlamp 302R, and has a structure that is reversed laterally for the left headlamp 302L.

[0066] 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). The near-infrared light source 410 may be a high-output LED (light-emitting diode). The light guide 420 receives a near-infrared beam, which is the light emitted from the near-infrared light source 410, on its light entrance surface 421, and emits illumination light having a predetermined light distribution from an exit surface 422 toward the front of the lamp.

[0067] The clearance lamp 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 light emitted from the white light source 332 at its end surface. The white light is reflected inside the light guide 334 and emitted forward of the lamp.

[0068] The light guide 420 of the lighting unit 400 has a back surface 424 facing the emission surface 422. The light guide 420 is disposed such that the back surface 424 faces a surface 336 of the light guide 334, which is the light emitting surface of the clearance lamp 330. The light guide 420 emits the emitted light of the clearance lamp 330 received by its back surface 424 from the emission surface 422 toward the front of the vehicle.

[0069] In this configuration, the near-infrared light source 410 and the white light source 332 are mounted on a common printed circuit board 340. In addition, a heat sink 342 is attached to the printed circuit board 340.

[0070] FIG. 9( a ) is a perspective view of the lighting unit 400 , and FIG. 9( b ) is a plan view of the lighting unit 400 .

[0071] A back surface 424 of the light guide 420 is provided with a plurality of steps 426 spaced apart in the optical axis direction of the near-infrared light source 410, and the steps 426 are formed at an incline with respect to the optical axis. The inclination angle of each step 426 is designed so that the light reflected on the surface is directed in the traveling direction of the vehicle. The steps 426 may be vapor-deposited with a metal such as aluminum to increase the reflectance. The parts of the back surface 424 other than the steps 426 are substantially parallel to the optical axis. The emitted light L1 of the near-infrared light source 410 propagates inside the light guide 420 in the optical axis direction (X direction in the figure), is reflected by the steps 426 of the back surface 424, and is emitted from the emission surface 422 in the direction forward of the lamp (Z direction). In FIG. 9(b), a representative light ray of an infrared beam emitted from the near-infrared light source 410 is indicated by a dashed line. In FIG. 9(b), the emitted light L3 from the clearance lamp 330 on the rear surface of the light guide 420 is indicated by a dashed line.

[0072] The above is the configuration of headlamp 302. According to this headlamp 302, by configuring the optical system of the lighting device of the gating camera with light guide 420, the degree of freedom in the shape and size of lighting unit 400 is increased compared to the case where a lens optical system or a reflective optical system is used, and it becomes possible to accommodate the existing lamp within the housing of the headlamp without impairing its function.

[0073] When white light is transmitted through the light guide, the light guide itself glows white due to internal reflection and diffusion. Therefore, although light guides have been used as clearance lamps in the past, it has been difficult to adopt them in lamps intended to illuminate objects, such as low beams and high beams. In this respect, in this embodiment, the illumination light for the active sensor is infrared light, so that even if a light guide is used in an optical system for forming the light distribution of illumination light, it will not glow white.

[0074] In addition, according to the headlamp 302, by arranging the clearance lamp 330 behind the lighting unit 400 that generates near-infrared illumination light, it is possible to prevent the near-infrared spectral components contained in the illumination light from overlapping with the white light emitted by the clearance lamp 330 and appearing red.

[0075] Furthermore, by forming a light distribution using reflection from a plurality of steps 426 provided on the light guide 420, a light distribution that spreads in the horizontal direction can be formed, and the entire horizontal field of view of the image sensor can be covered.

[0076] 10(a) and (b) are diagrams showing the results of simulating the light distribution pattern of the lighting unit 400 according to embodiment 1. Fig. 10(a) shows the luminous intensity distribution on a virtual vertical screen, and Fig. 10(b) shows the luminous intensity distribution in the vertical direction. In this configuration, the half-width of the illumination light is in the range of ±10° in the horizontal direction and ±7° in the vertical direction.

[0077] Referring to Fig. 10(b), this light distribution has two peaks in the vertical direction. Figs. 11(a) and 11(b) are diagrams explaining the cause of the occurrence of multiple peaks in the light distribution. The inventors recognized that one cause of the occurrence of multiple peaks is due to reflections on the top and bottom surfaces of the light guide 420. Below, several modifications for improving the luminous intensity distribution in the vertical direction will be described.

[0078] (Variation 1) 12(a) and (b) are diagrams showing a light guide 420A according to Modification 1. In Modification 1, the sagittal plane (YZ cross section) of the light guide 420A is inversely tapered toward the front of the vehicle, and the distance between the top surface 428 and the bottom surface 429 increases toward the front of the vehicle (Feature 1). Furthermore, the exit surface 422 of the light guide 420A has a curvature in the vertical direction (Feature 2). In this example, the exit surface 422 has a positive curvature.

[0079] 12(b) shows the light path in light guide 420A. By providing an inverse taper, reflection at top surface 428 and bottom surface 429 of light guide 420A is suppressed. When the taper angle of light guide 420A is larger than the divergence angle of the infrared beam in the vertical direction, reflection at top surface 428 and bottom surface 429 can theoretically be eliminated. Note that the present invention is not limited to this, and the taper angle may be smaller than the divergence angle of the beam. Even in this case, the effect of suppressing the occurrence of multiple peaks can be obtained.

[0080] Moreover, according to the first modification, the spread angle in the vertical direction of the emitted illumination light, that is, the irradiation range, can be controlled according to the curvature of emission surface 422 of light guide 420A.

[0081] 13(a) and (b) are diagrams showing the results of a simulation of a light distribution pattern when a light guide according to Modification 1 is used. Fig. 13(a) shows the luminous intensity distribution on a virtual vertical screen, and Fig. 13(b) shows the luminous intensity distribution in the vertical direction. As shown in Fig. 13(b), Modification 1 makes it possible to make the luminous intensity distribution in the vertical direction a single peak. This is the effect of inversely tapering the light guide 420A.

[0082] Moreover, in the first modification, the irradiation range in the vertical direction is ±4°. This is the effect of providing a curvature (R=300 mm) to the exit surface 422.

[0083] (Variation 2) 14(a) and (b) are diagrams showing a light guide 420B according to Modification 2. In this modification, absorbers 430, 432 are attached to at least one of the top surface 428 and the bottom surface 429 of the light guide 420B (both in this example) (Feature 3). The higher the absorption rate of the absorbers 430, 432, the more preferable, and 90% or more is suitable. The absorbers 430, 432 are materials that absorb the wavelength band of the near-infrared beam, and the type thereof is not limited.

[0084] 15(a) and (b) are diagrams showing the results of a simulation of the light amount distribution in the vertical direction in Modification Example 2. For comparison, the light amount distribution without an absorbent is shown. In the case without an absorbent, the light amount is divided into three peaks, whereas by attaching an absorbent, the reflected light on top surface 428 and bottom surface 429 of light guide 420B can be reduced, and the occurrence of multiple peaks can be suppressed.

[0085] (Variation 3) 16(a) and (b) are diagrams showing a light guide 420C according to Modification 3. In this modification, a light entrance surface 421 of the light guide 420C has a curvature in the horizontal direction (Feature 4). In this example, the light entrance surface 421 is a convex surface, which makes an emitted beam having a divergence angle closer to a parallel beam.

[0086] As indicated by the dashed-dotted line, when a divergent infrared beam is guided inside light guide 420, it is totally reflected at emission surface 422, causing a decrease in efficiency and stray light and ghosting. In contrast, by making the infrared beam closer to parallel light, it is possible to suppress total reflection at emission surface 422, suppress the decrease in efficiency, and suppress stray light and ghosting.

[0087] Alternatively, depending on the curvature of light entrance surface 421, the horizontal light distribution of the illumination light emitted from exit surface 422 of light guide 420C can be controlled.

[0088] (Variation 4) 17 is a diagram showing a light guide 420D according to Modification 4. In this modification, light entrance surface 421 of light guide 420D has a curvature in the vertical direction (Feature 5). In this example, light entrance surface 421 is a convex surface, which makes an outgoing beam having a divergence angle closer to a parallel beam.

[0089] This allows the vertical light distribution of the illumination light emitted from emission surface 422 of light guide 420D to be controlled according to the curvature of the light entrance surface. In addition, the horizontal spread of the infrared light reflected by step 426 is suppressed, so that the infrared light can be prevented from entering the top and bottom surfaces of the light guide.

[0090] It should be noted that the features 1 to 5 described in the first to fourth modifications can be combined in any manner.

[0091] The present invention has been described above based on an embodiment. This embodiment is merely an example, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component and each processing step, and that such modifications are also within the scope of the present invention. Such modifications will be described below.

[0092] In the embodiment, an illumination device for a gating camera has been described, but the application of the present invention is not limited to this, and the present invention can be applied to illumination devices for various active sensors.

[0093] In the embodiment, the light guide of the lighting unit 400 is disposed in front of the clearance lamp 330, but the type of the white light source is not limited to the clearance lamp 330, and the light guide may be disposed in front of a low beam lamp, an ADB (Adaptive Driving Beam) lamp, or a daytime running lamp (DRL). If the light guide is not visually recognized as red, the lighting unit 400 can be disposed at a position unrelated to the white light source.

[0094] 18(a) and (b) are front views showing a schematic layout of the lighting unit 400. In Fig. 18(a), the near-infrared light source 410 is disposed inside the headlamp 302 on the vehicle outer side with its optical axis facing the vehicle center. In Fig. 18(b), the near-infrared light source 410 is disposed inside the headlamp 302 on the vehicle center side with its optical axis facing the vehicle outer side.

[0095] (Embodiment 2) In the second embodiment, another configuration of the lighting unit will be described.

[0096] The lighting unit 400 corresponds to the lighting device 22 in Fig. 1. In the first embodiment, the illumination light emitted by the lighting unit 400 is near-infrared light or mid-infrared light, but in the second embodiment, it may be visible light having a predetermined wavelength.

[0097] 19 is an exploded perspective view of a headlamp 302 according to the second embodiment. The headlamp 302 includes a high beam / low beam light source 304, a camera unit 308, an outer lens 310, an extension 312, a lamp body 314, and an illumination unit 400. The illumination unit 400 is provided on the rear side of the extension 312. The extension 312 is provided with an opening 313 so that the emitted light of the illumination unit 400 can pass through. The position of the illumination unit 400 is not particularly limited, and may be provided, for example, below the headlamp 302.

[0098] 20 is an exploded perspective view of the lighting unit 400. The lighting unit 400 includes a plurality of laser diodes 402_1 to 402_N, a heat sink 404, a housing 406, a plurality of condenser lenses 440_1 to 440_N, and a fly's eye lens 450. In this example, N=6.

[0099] A plurality of laser diodes 402_1 to 402_N are arranged side by side in the horizontal direction (X direction in the drawing). The laser diode 402 emits an emission beam having a certain divergence angle.

[0100] The heat sink 404 supports the rear surface side of the multiple laser diodes 402. The heat sink 404 and the laser diodes 402 are thermally coupled, and the heat of the laser diodes 402 is diffused and radiated via the heat sink 404.

[0101] The plurality of condenser lenses 440_1 to 440_N are provided corresponding to the plurality of laser diodes 402_1 to 402_N. Each condenser lens 440_i (1≦i≦N) is provided on the optical path of an emission beam from a corresponding one of the plurality of laser diodes 402_i, and emits the emission beam by making it closer to a parallel beam.

[0102] Each of the condenser lenses 440 has a different focal length in the horizontal direction (X direction) and the vertical direction (Y direction). The plurality of condenser lenses 440_1 to 440_N are integrally formed as one lens unit 409.

[0103] 21(a) is a diagram showing a configuration example of the condenser lens 440. The condenser lens 440 is configured by bonding two cylindrical lenses 440a and 440b whose power directions are perpendicular to each other. The cylindrical lens 440a on the side of the laser diode 402, which is the light source, has a power direction in the horizontal direction (X direction), and the cylindrical lens 440b on the exit surface side has a power direction in the vertical direction (Y direction).

[0104] Returning to Fig. 20, the fly-eye lens 450 diffuses the light emitted from the multiple condenser lenses 440_1 to 440_N. Fig. 21(b) is a perspective view of the fly-eye lens 450. The fly-eye lens 450 is also called a diffusion lighting element, and is an imaging element in which the same single lenses 452 are arranged in a matrix.

[0105] FIG. 22(a) is a cross-sectional view of the lighting unit 400, and FIG. 22(b) is a perspective view of the exterior of the lighting unit 400. As shown in FIG.

[0106] The housing 406 has two openings on opposite sides, with the heat sink 404 fixed to one opening side and the lens unit 409 and the fly's eye lens 450 fixed to the other opening side.

[0107] The above is the configuration of the lighting unit 400. Next, its operation will be described. Figures 23(a) and (b) are ray diagrams of the lighting unit 400. Figure 23(a) is a ray diagram in the XZ plane, and Figure 23(b) is a ray diagram in the YZ plane. As shown in Figure 23(a), the condenser lens 440 has a first power in the horizontal direction, and the emitted beam of the laser diode 402 is made to approach a parallel light in the horizontal direction. The emitted light of the fly's eye lens 450 is radiated in an angular range of ±θ(°) in the horizontal direction.

[0108] 23(b), the condenser lens 440 has a second power in the vertical direction, and the emitted beam of the laser diode 402 is made to approach parallel light in the vertical direction as well. The emitted light of the fly's eye lens 450 is radiated in an angular range of ±φ in the vertical direction.

[0109] The horizontal spread angle θ can be designed using as parameters the first power (focal length) of the condenser lens 440, the distance between the laser diode 402 and the condenser lens 440, and the power (focal length) of the single lens 452 that constitutes the fly's eye lens 450. Similarly, the vertical spread angle φ can be designed using as parameters the second power of the condenser lens 440, the distance between the laser diode 402 and the condenser lens 440, and the power of the single lens 452 that constitutes the fly's eye lens 450.

[0110] 24 is a diagram showing the luminance distribution (simulation result) of the outgoing beam of the lighting unit 400. In this example, a light distribution of θ=±17° in the horizontal direction and φ=±10° in the vertical direction is formed.

[0111] According to the lighting unit 400, a combination of a condenser lens and a fly-eye lens can form an appropriate light distribution. In addition, it is possible to eliminate areas with locally high brightness in the light-emitting surface, and it is possible to satisfy the laser safety standard. Specifically, the lighting unit 400 is classified as laser class 1, and is required to have a ratio (AE / AE) of the exposed radiation amount (AE) to the exposed radiation limit (AEL) of less than 1. According to this embodiment, it is possible to satisfy the laser safety standard for laser class 1.

[0112] The present invention has been described using specific terms based on the embodiments, but the embodiments merely show one aspect of the principles and applications of the present invention, and many modifications and changes in arrangement are permitted to the embodiments without departing from the spirit of the present invention as defined in the claims. [Industrial Applicability]

[0113] The present disclosure is applicable to active sensors. [Explanation of symbols]

[0114] S1 Light emission timing signal S2 Exposure timing signal 10. Sensing System 20 Gating Camera 22 Lighting equipment 24 Image Sensor 26 Camera Controller 28 Image Processing Device 300 Automobiles 302 Headlamp 304 High beam / low beam light source 306 Turn signal lamp 308 Camera Unit 310 Outer Lens 312 Extension 314 Lamp body 320 Lighting unit 330 Clearance Lamp 332 White light source 334 Light guide 340 Printed Circuit Board 342 Heat sink 350 Base 400 lighting units 402 Laser Diode 404 Heatsink 406 Case 410 Near-infrared light source 420 Light guide 422 Injection surface 424 Back 426 Steps 428 Top 429 Bottom 440 Condenser Lens 450 Fly Eye Lens 452 Single Lens

Claims

1. A white lamp and an illumination device for the active sensor; Equipped with The lighting device includes: A near-infrared light source; a first light guide that receives light emitted from the near-infrared light source and emits illumination light having a predetermined light distribution from an emission surface; Equipped with The white lamp is A white light source; a second light guiding body provided separately from the first light guiding body and guiding the white light of the white light source; Including, the first light guide is disposed such that a rear surface of the first light guide faces a light emitting surface of the second light guide, and the light emitted from the second light guide and received by the rear surface of the first light guide is emitted from the light emitting surface of the second light guide; A vehicle lamp, characterized in that the white light source and the near-infrared light source are mounted on the same substrate.

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

3. 3. The vehicle lamp according to claim 1, wherein the rear surface of the first light guide is provided with a plurality of steps spaced apart from each other in a direction of an optical axis of the near-infrared light source.

4. 4. The vehicle lamp according to claim 1, wherein the illumination device and the white lamp are modularized.

5. 5. The vehicle lamp according to claim 1, further comprising an image sensor which constitutes a gating camera together with the illumination device.

6. The steps are provided over the entire longitudinal surface of the rear surface, The vehicular lamp according to claim 3 , wherein each of the plurality of steps is formed to be inclined with respect to the optical axis.

7. A lighting device for an active sensor is provided, The lighting device includes: a semiconductor light source that emits an infrared light beam; a light guide that receives the infrared light beam at a light entrance surface and emits illumination light having a predetermined light distribution from an exit surface; Equipped with a back surface of the light guide facing the emission surface is provided with a plurality of steps spaced apart in an optical axis direction of the semiconductor light source; the plurality of steps are provided over the entire longitudinal surface of the rear surface, and each of the plurality of steps is formed to be inclined with respect to the optical axis, The sagittal plane of the light guide is inversely tapered toward the front of the vehicle, and the distance between the top surface of the light guide and the bottom surface of the light guide increases toward the front of the vehicle.

8. The vehicular lamp according to claim 7, wherein the exit surface of the light guide has a curvature in a vertical direction.

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

10. 10. The vehicle lamp according to claim 7, wherein the light entrance surface of the light guide has a curvature in a horizontal direction.

11. 8. The vehicular lamp according to claim 7, wherein the semiconductor light source is disposed on an outer side of the vehicle within the vehicular lamp, with its optical axis directed toward a center of the vehicle.

12. 8. The vehicle lamp according to claim 7, wherein the semiconductor light source is disposed on a vehicle center side within the vehicle lamp, with the optical axis of the semiconductor light source facing outward from the vehicle.

13. 13. The vehicle lamp according to claim 7, further comprising an image sensor which constitutes a gating camera together with the illumination device.

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