Occupant monitoring device

Abstract

To provide an occupant monitoring apparatus which can suppress the occurrence of such a situation that infrared light reflected on a reflection translucent member is visually recognized by an occupant.SOLUTION: An occupant monitoring apparatus according to the present invention comprises: an infrared light irradiation unit 12 which irradiates, with infrared light L2, a front windshield 3 provided in a vehicle 2 to transmit visible light and reflect the infrared light; a camera 13 which images a driver D of the vehicle 2 with the infrared light L2 reflected on the front windshield 3; and a housing 6 for housing the infrared light irradiation unit 12 and the camera 13. The infrared light irradiation unit 12 is provided in the housing 6 such that a reflection position R of the infrared light L2 on the front windshield 3 is superimposed on an irradiation region 19 of a headlight 18 of the vehicle 2 when viewed from a view point position of the driver D.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an occupant monitoring device that irradiates an occupant of a vehicle with infrared light and captures an image of the behavior of the occupant. [Background technology]

[0002] A head-up display device generates and displays a virtual image by using display light reflected by a reflective translucent member, such as the vehicle's front windshield or combiner, which is superimposed on the real scene (the scenery in front of the vehicle) that passes through the reflective translucent member.This device contributes to safe and comfortable vehicle operation by providing the vehicle occupant (driver) with the information they desire through a virtual image while minimizing the need for eye movement.

[0003] In addition, some head-up display devices are equipped with a monitoring system (occupant monitoring device) that captures images of occupants by irradiating them with infrared light reflected by a reflective, translucent member, and uses the captured images to determine the occupant's behavior, such as looking away or falling asleep.

[0004] For example, the head-up display device described in Patent Document 1 forms a display image by reflecting visible light emitted from a display means toward the driver (user) using a combiner member, and further comprises an infrared irradiation means that irradiates infrared light toward the driver, a mirror member that reflects the visible light emitted from the display means toward the combiner member and transmits the infrared light reflected by the driver and the combiner member, a plurality of imaging means that sense the infrared light that transmits through the mirror member and capture images of the driver from different directions, and an image processing means that calculates the position of the driver's eyes based on the images captured by the imaging means, making it possible to accurately calculate the position of the driver's eyes. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-126984 Summary of the Invention [Problem to be solved by the invention]

[0006] When an occupant monitoring device captures an image of an occupant using infrared light, the infrared light source may be reflected by the reflective / transparent member in a dark environment outside the vehicle, such as at night, and may be visually recognized by the occupant as a red ball (point light source). This so-called "ball appearance" can cause discomfort to the occupant, and is particularly annoying to the driver while driving.

[0007] The present invention has been made in consideration of the above circumstances, and has an object to provide an occupant monitoring device that can prevent infrared light reflected by a reflective, translucent member from being visible to an occupant. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides an occupant monitoring device comprising: infrared light irradiating means for irradiating infrared light onto a reflective translucent member that is provided in a vehicle and transmits visible light but reflects infrared light; imaging means for imaging an occupant of the vehicle using the infrared light reflected by the reflective translucent member; and a housing that accommodates the infrared light irradiating means and the imaging means, wherein the infrared light irradiating means is provided in the housing such that, when viewed from the viewpoint of the occupant or another occupant of the vehicle, the reflection position of the infrared light on the reflective translucent member overlaps with the illumination area of ​​the vehicle headlights.

[0009] Here, the occupant's viewpoint position is the position assumed to be the viewpoint (eye position) of one of the vehicle's occupants, and can be a position included in a certain spatial area determined based on the occupant's seat position and physique.

[0010] The infrared light irradiation means may be provided on the housing so that, when viewed from the viewpoint of the occupant or the other occupant, the reflection position of the infrared light in the reflective translucent member overlaps with the illumination area of ​​the low beam of the headlight.

[0011] In addition, the infrared light irradiation means may be provided on the housing so that, when viewed from the viewpoint of the occupant or the other occupant, the reflection position of the infrared light in the reflective translucent member overlaps with a high-brightness area of ​​the irradiation area having an irradiation brightness higher than the reflection brightness.

[0012] Furthermore, the occupant may be a driver seated in the driver's seat of the vehicle. [Effects of the Invention]

[0013] According to the present invention, it is possible to suppress the occurrence of a situation in which infrared light reflected by a reflective / translucent member is visually recognized by an occupant. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is an explanatory diagram showing a vehicle provided with a head-up display device incorporating an occupant monitoring device according to an embodiment of the present invention; [Figure 2] FIG. 2 is an explanatory diagram showing the configuration of the head-up display device of FIG. [Figure 3] FIG. 2 is a perspective view showing the appearance of the head-up display device of FIG. [Figure 4] FIG. 2 is a plan view showing the appearance of the head-up display device of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings.

[0016] 1 and 2, a head-up display device (HUD) 1 incorporating an occupant monitoring device according to this embodiment is provided inside an instrument panel 4 located below a front windshield 3 of a vehicle 2, and projects display light L1, which is visible light, onto a part of the front windshield 3. The display light L1 is reflected by the front windshield 3 to generate a virtual image V, which is superimposed on an actual scene transmitted through the front windshield 3 and is visible to a driver D seated in a driver's seat (not shown) behind a steering wheel 5.

[0017] The HUD 1 also has a function of monitoring the state of the driver D, and captures an image of the driver D by irradiating the driver D with infrared light L2.

[0018] In detail, the HUD 1 is enclosed in a housing 6 molded from a black ABS resin or the like to prevent external light from entering, and is separated from the outside, and an opening 8 is formed in the housing 6 to which a transparent cover glass 7 made from a polycarbonate or the like is attached. Inside the housing 6, a display unit 9, a plane mirror 10, a concave mirror 11, an infrared light irradiation unit 12, and a camera 13 are held and housed.

[0019] 2, the cover glass 7 is a quadrilateral plate that is curved downward and convex, and is provided with a light-shielding portion 14 that blocks visible light along its entire periphery (the periphery of the four sides). The light-shielding portion 14 is made of a transparent base material such as polycarbonate with a black printed layer formed on it.

[0020] The display unit 9 is provided with a display 15 consisting of a light source, a liquid crystal panel, etc., and projects and displays visible light image light (display light L1) from the display 15. The plane mirror 10 is made of glass molded to have a flat surface, with a metal such as aluminum or a dielectric multilayer film deposited on it, and simply reflects visible light. The concave mirror 11 is made of resin such as polycarbonate molded to have a concave surface, with a metal such as aluminum deposited on it, and magnifies and reflects visible light.

[0021] 3, the infrared light irradiation unit 12 is provided in the housing 6 below the cover glass 7 and at the center side in the vehicle width direction of the vehicle 2 so as to face the light-shielding portion 14. An infrared light transmitting portion 16 that transmits infrared light is provided at the portion of the light-shielding portion 14 that faces the infrared light irradiation unit 12 (the portion of the light-shielding portion 14 that corresponds to the infrared light transmitting portion 16 is made of a black printed layer that blocks visible light and transmits infrared light, and the other portion is made of a black printed layer that blocks visible light and infrared light). The infrared light irradiation unit 12 irradiates infrared light (near-infrared light) L2 emitted by a light source (point light source) made of a light-emitting diode (LED) through the infrared light transmitting portion 16 toward the front windshield 3.

[0022] At this time, when viewed from the viewpoint position of the driver D (here, any position within the designed eyebox 17; Figure 1 shows three viewpoint positions at different heights within the eyebox 17), the reflection position R of the infrared light L2 on the front windshield 3 (the position where the optical axis of the light source of the infrared light irradiation unit 12 intersects with the front windshield 3) overlaps with at least a portion of the illumination area 19 (the entire area reached by the light emitted by the headlight 18) of the headlight 18 of the vehicle 2 (for example, the high-illuminance area surrounded by an isolux curve of 80% of the maximum illuminance in the illumination area 19) (in Figure 1, since the distance from the headlight 18 of the vehicle 2 to the illumination area 19 on the road surface is long compared to the dimensions of the vehicle 2, the space in front of the vehicle 2 and part of the road surface are omitted from the illustration by broken lines).

[0023] On the other hand, the camera 13 is provided in the housing 6 below the cover glass 7, facing the infrared light transmitting section 16, toward the center of the vehicle width direction and in front of the infrared light irradiation unit 12, and is equipped with an imaging element that is sensitive to the infrared light L2 in the wavelength band irradiated from the infrared irradiation unit 12, and a lens that can transmit the infrared light L2 and form an image on the imaging element, thereby capturing near-infrared images.

[0024] In addition, in the case of this embodiment, although detailed illustration is omitted here, the housing 6 has a pair of peripheral walls that are approximately perpendicular (intersect) with the vehicle width direction, and the infrared light irradiation unit 12 and the camera 13 are provided in a space in the housing 6 that is slightly inside one peripheral wall (one of the peripheral walls) of the pair of peripheral walls that is located closer to an imaginary center line that divides the vehicle into two equal parts left and right. Note that the housing 6 here has four peripheral walls, and the two peripheral walls that are approximately along the vehicle width direction shown in Figure 2 are configured as upright walls that connect the ends of the pair of peripheral walls.

[0025] In the HUD 1, display light L1 from the display unit 9 is reflected by a plane mirror 10, then magnified and reflected by a concave mirror 11, passes through a transparent central portion 17 surrounded by a light-shielding portion 14 of the cover glass 7, and is projected onto the front windshield 3. The display light L1 projected onto the front windshield 3 is magnified and reflected toward the driver D, generating a virtual image V which is superimposed on the real view passing through the front windshield 3 and displayed to the driver D.

[0026] On the other hand, the infrared light L2 from the infrared light irradiation unit 12 passes through the infrared light transmitting portion 16 of the light blocking portion 14 of the cover glass 7 and is projected onto the front windshield 3, where it is reflected by the front windshield 3 toward the driver D and irradiates the driver D. Then, when reflected by the driver D, part of the infrared light L2 travels back along the opposite path, passes through the infrared light transmitting portion 16, and is incident on the camera 13, whereby the driver D is imaged. This imaging is performed periodically or irregularly while the virtual image V is being displayed, and the driver D is monitored based on the captured image.

[0027] The occupant monitoring device of the HUD 1 according to this embodiment includes an infrared light irradiation unit 12 that irradiates infrared light L2 onto a front windshield 3 that is provided in a vehicle 2 and transmits visible light but reflects infrared light, a camera 13 that captures an image of a driver D of the vehicle 2 using the infrared light L2 reflected by the front windshield 3, and a housing 6 that accommodates the infrared light irradiation unit 12 and the camera 13. The infrared light irradiation unit 12 is configured to irradiate the front windshield 3 with infrared light L2 so that, as viewed from the viewpoint of the driver D, the reflection position R of the infrared light L2 on the front windshield 3 is aligned with the head of the vehicle 2. Since the infrared light emitting unit 12 is provided (housed) in the housing 6 so as to overlap with the illumination area 19 of the headlight 18, even in a dark environment outside the vehicle where the light source of the infrared light emitting unit 12 is reflected on the front windshield 3 and is seen by the driver D as a red ball if the background is dark, if the headlight 18 is turned on, the illumination area 19 is superimposed on the red ball and the background of the red ball becomes bright, thereby preventing the infrared light L2 reflected by the front windshield 3 from being seen by the occupants (seeing the ball).

[0028] It is desirable that the infrared light irradiation unit 12 is provided in the housing 6 so that, when viewed from the viewpoint of the driver D, the reflection position R of the infrared light L2 on the front windshield 3 overlaps with the low beam irradiation area of ​​the headlights 18 of the vehicle 2, thereby making it possible to suppress the occurrence of glare whenever the headlights 18 are turned on (not only in the case of high beam but also in the case of low beam).

[0029] In addition, it is desirable that the infrared light irradiation unit 12 is provided in the housing 6 so that, when viewed from the viewpoint of the driver D, the reflection position R of the infrared light L2 on the front windshield 3 overlaps with a high-brightness area of ​​the irradiation area 19 having an irradiation brightness higher than the reflection brightness of the infrared light L2 at the reflection position R.

[0030] The reflected luminance here refers to the luminance of the infrared light L2 reflected by the front windshield 3 when the infrared light L2 emitted from the light source is reflected by the front windshield 3 and irradiated to the driver D. The illumination luminance of the illumination area 19 refers to the luminance (background luminance) of light reflected by the road surface, etc. that is the target of illumination by the headlights 18, and more specifically refers to the luminance of the road surface, etc. that is reflected by the road surface, etc. when the headlights 18 illuminate the road surface, etc. and is visible to the driver D. The illumination luminance of the high-luminance area of ​​the illumination area 19 is higher than the reflected luminance of the infrared light L2, and therefore, by having the reflection position R overlap with the high-luminance area, the occurrence of the ball appearing can be more reliably suppressed.

[0031] Although the embodiments for carrying out the present invention have been described above, the embodiments of the present invention are not limited to those described above, and may be modified as appropriate within the scope of the invention.

[0032] For example, in the above embodiment, the front windshield of the vehicle is used as the reflective and translucent member, but instead of the front windshield, a combiner or the like may be used as the reflective and translucent member.

[0033] In addition, the infrared light irradiation unit 12 may be provided in the housing 6 so that the reflection position R of the infrared light L2 on the front windshield 3 overlaps with the irradiation area 19 of the headlight 18 of the vehicle 2 when viewed from the viewpoint of a passenger other than the driver D sitting in the passenger seat or rear seat, rather than the driver D sitting in the driver's seat of the vehicle 2. [Explanation of symbols]

[0034] 2 vehicles 3 Front windshield (reflective and translucent material) 6 Housing 12 Infrared light irradiation unit (infrared light irradiation means) 13 Camera (imaging means) 18 Headlight 19 Irradiation area D Driver (passenger) L2 infrared light R Reflection Position

Claims

1. an infrared light irradiating means for irradiating infrared light onto a reflective transmissive member that is provided in the vehicle and transmits visible light and reflects infrared light; an imaging means for imaging an occupant of the vehicle using infrared light reflected by the reflective light-transmitting member; a housing that houses the infrared light irradiating means and the imaging means, An occupant monitoring device characterized in that the infrared light irradiation means is provided in the housing so that, when viewed from the viewpoint of the occupant or another occupant of the vehicle, the reflection position of the infrared light in the reflective translucent member overlaps with the illumination area of ​​the headlights of the vehicle.

2. The occupant monitoring device according to claim 1, characterized in that the infrared light irradiating means is provided on the housing so that, when viewed from the viewpoint of the occupant or the other occupant, the reflection position of the infrared light in the reflective translucent member overlaps with the illumination area of ​​the low beam of the headlight.

3. The occupant monitoring device according to claim 1 or claim 2, characterized in that the infrared light irradiation means is provided on the housing so that, when viewed from the viewpoint position of the occupant or the other occupant, the reflection position of the infrared light in the reflective translucent member overlaps with a high-brightness area of ​​the irradiation area having an irradiation brightness higher than the reflection brightness of the infrared light at the reflection position.

4. 4. The occupant monitoring device according to claim 1, wherein the occupant is a driver seated in a driver's seat of the vehicle.

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