JP2012011976A - Face image pickup apparatus for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a face image pickup apparatus for a vehicle which can image a bright spot on a driver's eyeball correctly by an imaging means even if the driver wears glasses.SOLUTION: A CCD camera 20 for imaging a driver m's face and a near-infrared LED 21 for irradiating light to the driver m's eyeball 27 for detection of the eye direction are arranged at forward side from the steering wheel 13. The CCD camera 20 and the near-infrared LED 21 are disposed to separate mutually from more than a predetermined distance in the vertical direction and the width direction of the vehicle. Here the predetermined distance is set in such a distance that a bright spot on the glasses where the light of near-infrared LED 21 reflects on the glasses 25 and a bright spot on the eyeball where the light of near-infrared LED 21 reflects on the eyeball 27 are imaged with no overlap on the CCD camera 20.

Description

  The present invention relates to a face image capturing device for a vehicle that is mounted on a vehicle and captures a driver's face image in order to detect a driver's line-of-sight direction and the like.

  As a device for recognizing the behavior of a driver while driving, a vehicle equipped with a face image capturing device is known. This face image capturing apparatus captures an image of a driver's face seated in a driver's seat by an imaging means such as a CCD camera, and analyzes the captured image to detect the driver's face orientation, line-of-sight direction, and the like (for example, Patent Document 1).

  In the face image capturing apparatus described in the cited document 1, a camera as an imaging unit and an infrared projector are integrated as a camera assembly, and the camera assembly is attached to a steering column having a tilt mechanism. In this face image pickup device, since the camera assembly moves integrally with the steering column, even if the tilt angle in the vertical direction of the steering wheel is adjusted by the operation of the tilt mechanism, the projector assembly passes through the opening between the spokes of the steering wheel. It is possible to perform light projection to the driver and capture of a face image by the camera.

JP 2007-69680 A

  However, in this conventional face image capturing device, since the camera as an imaging means and the infrared projector are arranged close to each other as a camera assembly, the light is projected from the projector when the driver wears glasses. When the reflected light is reflected on both the spectacles and the driver's eyeball, the two bright spots formed by these reflections may overlap when viewed from the camera. If the bright spot on the eyeglasses overlaps with the bright spot on the eyeball in this way, the bright spot on the eyeball cannot be captured properly, and the driver's line-of-sight direction can be accurately detected. There is concern about disappearing.

  Therefore, the present invention is intended to provide a vehicle face image pickup device that can accurately pick up the bright spot on the driver's eyeball with the image pickup means even when the driver wears glasses. is there.

The vehicle face image capturing apparatus according to the present invention employs the following means in order to solve the above problems.
According to a first aspect of the present invention, there is provided a steering wheel (for example, the steering wheel 13 of the embodiment) disposed in front of a driver's seat in the vehicle interior and a vehicle front side of the steering wheel in the vehicle interior. An image pickup means (for example, the CCD camera 20 of the embodiment) for picking up a face image of a driver seated on the vehicle, and a light projection means (for example, implementation) for projecting visible light or invisible light toward the driver's eyeball In the form of a near-infrared LED 21), the imaging means and the light projecting means are arranged apart from each other by a predetermined distance in the vertical direction and the vehicle width direction, and the predetermined distance is The light projected by the light projecting means is reflected on the eyeglasses worn by the driver (for example, the eyeglass bright spot 26 in the embodiment), and the light projected by the light projecting means. The bright spot on the eyeball where the reflected light is reflected on the eyeball of the driver (for example, the bright spot on the eyeball 28 in the embodiment) is set to a distance that does not overlap when viewed from the imaging means. And

  According to a second aspect of the present invention, in the face image capturing device for a vehicle according to the first aspect, the light projecting unit is disposed above the eyeball position of the driver who is seated in the driver seat. In the case where the imaging means is arranged vertically above the imaging means, and in the case where the imaging means is arranged vertically below the eye position of the driver seated in the driver's seat, the imaging means is vertical. It is arranged at the lower side in the direction.

According to the first aspect of the present invention, even when the driver wears spectacles, the spectacle bright spot and the eyeball bright spot do not overlap with the imaging means so that they do not overlap when viewed from the image pickup means. Since the light means are arranged at a predetermined distance or more apart in the vertical direction and the vehicle width direction, the bright spot on the eyeball of the driver can be detected more reliably without being adversely affected by the bright spot on the glasses.
In the present invention, since the imaging means and the light projecting means are separated by a predetermined distance or more in both the vertical direction and the vehicle width direction, the driver's face is either in the vertical direction or in the horizontal direction with respect to the front of the vehicle. Even when it is tilted, the overlapping of the bright spot on the eyeglasses and the bright spot on the eyeball seen from the imaging means can be reliably prevented.

  According to the second aspect of the present invention, when the image pickup means is disposed vertically above the driver's eyeball position, the light projecting means is disposed vertically above the image pickup means, and the image pickup means is operated. When the eyeball position is placed vertically below the eyeball position of the person, the light projection means is placed vertically below the image pickup means, so that the bright spot on the eyeglasses and the bright spot on the eyeball are appropriate in the vertical direction. Can be separated.

1 is a schematic side view of a passenger compartment showing a schematic configuration of a face image capturing device according to a first embodiment of the present invention. It is a front view which shows the vehicle interior of the vehicle which installed the face image imaging device of 1st Embodiment of this invention. It is a figure which shows the face image imaged with the face image imaging device of 1st Embodiment of this invention. It is a typical side view which shows the arrangement | positioning impossible range of the light projector of 1st Embodiment of this invention. It is a typical side view of the vehicle interior which shows schematic structure of the face image imaging device of 2nd Embodiment of this invention. It is a front view which shows the vehicle interior of the vehicle which employ | adopted the face image imaging device of 2nd Embodiment of this invention. It is a figure which shows the face image imaged with the face image imaging device of 2nd Embodiment of this invention.

Embodiments of the present invention will be described below with reference to the drawings.
First, the first embodiment shown in FIGS. 1 to 4 will be described.
FIG. 1 is a diagram illustrating a configuration of a face image capturing apparatus 1 according to this embodiment, and FIG. 2 is a diagram illustrating a vehicle interior of a vehicle in which the face image capturing apparatus 1 is installed.
In these drawings, 11 is a seat of the driver's seat on which the driver m is seated, 12 is an instrument panel installed in front of the driver's seat, 13 is a steering wheel, 14 is a steering shaft (not shown). It is a steering column to support.
The steering wheel 13 can be adjusted in the vertical inclination angle by a tilt mechanism 15 provided in the steering column 14 and can be adjusted in the front-rear direction by a telescopic mechanism 16 provided in the steering shaft. .

  The face image capturing apparatus 1 includes a CCD camera 20 that is an image capturing unit that captures the face of the driver m, a near-infrared LED 21 that is a light projecting unit that irradiates the eyeball 27 of the driver m, and the CCD camera 20. A control device 22 that controls the infrared LED 21 and performs image processing and analysis based on the detection signal of the CCD camera 20 is provided. The result of image processing and analysis performed by the control device 22 is used, for example, in an aside alarm device, and activates the alarm means 23 when it is determined that the driver m is looking aside. The light projecting means is not limited to the near-infrared LED 21 and may be any other point light source that irradiates visible light or invisible light toward the occupant's eyeball 27.

  In the image processing and analysis in the face image capturing device 1, for example, the direction of the face of the driver m is detected based on the face image of the driver m, and light is emitted from the near infrared LED 21 to the eyeball 27 of the driver m. The position of the bright spot on the iris when illuminated (the bright spot 28 on the eyeball) and the position of the pupil are detected, and the line-of-sight direction of the driver m is determined based on the distance between the bright spot on the iris and the pupil. .

By the way, in the case of this face image pickup device 1, the CCD camera 20 is vertically above the central axis A of the steering wheel 13 in the front view of the steering wheel 13, and the steering wheel 13 is a tilt mechanism 15 or a telescopic mechanism 16. It is installed on the upper surface of the instrument panel 12 so as to be above the upper end portion 13a of the steering wheel 13 when the position is adjusted to the maximum ascending position (upper limit position).
The installation height of the CCD camera 20 is such that the driver h's hand h that rotates the steering wheel 13 reaches the upper end 13a of the steering wheel 13 with the steering wheel 13 adjusted to the maximum ascending position. However, it is desirable that the height be higher than the hand h.

  The near-infrared LED 21 of the face image pickup device 1 is installed on the instrument panel 12 close to the root portion of the front pillar 17 in front of the driver's seat. The installation position of the near infrared LED 21 is a position that does not overlap with the arm tip of the driver m who rotates the steering wheel 13 in the front view of the steering wheel 13, and is lateral to the center axis A of the steering wheel 13 in the vehicle width direction. In addition, the position is outside the steering wheel 13. In the face image capturing apparatus 1 of this embodiment, when the steering wheel 13 is adjusted to the standard position, the CCD camera 20 and the near-infrared LED 21 are concentric with the center axis A of the steering wheel 13 as the center. It is arranged at an upper position, that is, a position equidistant from the central axis A.

FIG. 3 is a diagram illustrating an image captured by the face image capturing apparatus 1.
As shown in FIGS. 1 and 2, the CCD camera 20 and the near-infrared LED 21 are arranged apart from each other by a predetermined distance or more in the vertical direction and the vehicle width direction. Here, the predetermined distances in the vertical direction and the vehicle width direction are distances determined on the assumption that the driver m wears the glasses 25. As shown in FIG. As seen from the CCD camera 20, the bright spot 26 on the eyeglasses where the light emitted is reflected on the eyeglasses 25 and the bright spot 28 on the eyeballs where the light projected by the near-infrared LED 21 is reflected on the iris of the eyeball 27 are viewed from the CCD camera 20. Sometimes (when projected by the CCD camera 20), the distance does not overlap each other. Each of the predetermined distances is preferably a distance where the spectacle bright spot 26 does not overlap with the pupil on the eyeball 27 in addition to the bright spot 28 on the eyeball.

In the case of this embodiment, as shown in FIG. 1, the CCD camera 20 that is an imaging unit is arranged vertically below the position of the eyeball 27 of the driver m seated on the seat 11, and is a light projecting unit. A certain near-infrared LED 21 is arranged so as to be further on the lower side in the vertical direction than the CCD camera 20.
FIG. 4 illustrates the reason why it is advantageous if the near-infrared LED 21 is further disposed below the vertical direction when the CCD camera 20 is disposed below the eyeball 27 of the driver m. FIG. In the figure, a is the imaging range when the CCD camera 20 captures the iris region of the eyeball 27 of the driver m, and b is the region on the glasses 25 that intersects the imaging range at this time. As shown in FIG.
Therefore, when the near-infrared LED 21 is installed inside the reflection range b, the image of the near-infrared LED 21 on the eyeball 27 (the bright spot 28 on the eyeball) and the image of the near-infrared LED 21 on the glasses 25 (on the glasses) The possibility that the bright spots 26) overlap and move to the CCD camera 20 increases. However, in this embodiment, since the near-infrared LED 21 is arranged further vertically below the CCD camera 20, the image of the near-infrared LED 21 on the glasses 25 (the bright spot 26 on the glasses) is the eyeball 27 (eyeball). The position is below the upper bright spot 28).

  As described above, the face image capturing apparatus 1 prevents the bright spot 26 on the eyeglass from overlapping the bright spot 28 on the eyeball and being reflected on the CCD camera 20 even when the driver m wears the glasses 25. In addition, since the CCD camera 20 and the near-infrared LED 21 are arranged apart from each other by a predetermined distance in the vertical direction and the vehicle width direction, the bright spot 28 on the eyeball of the driver m without being adversely affected by the bright spot 26 on the glasses. Can be detected more reliably.

  In the case of the face image pickup device 1, the CCD camera 20 and the near-infrared LED 21 are arranged apart from each other by a predetermined distance in both the vertical direction and the vehicle width direction, so that the face of the driver m is in front of the vehicle. On the other hand, even when tilted in either the vertical direction or the horizontal direction, it is possible to more reliably prevent the spectacle bright spot 26 from overlapping the eyeball bright spot 28 and appearing on the CCD camera 20.

  In the face image capturing apparatus 1, the near-infrared LED 21 is further below the CCD camera 20 in the vertical direction under the situation where the CCD camera 20 is disposed vertically below the position of the eyeball 27 of the driver m. Therefore, the bright spot 26 on the eyeglasses and the bright spot 28 on the eyeball reflected on the CCD camera 20 can be appropriately separated in the vertical direction.

Next, a second embodiment of the present invention shown in FIGS. 5 to 7 will be described.
The second embodiment is different from the first embodiment except for the arrangement of the CCD camera 20 that is an image pickup means and the arrangement of the near-infrared LED 21 that is a light projection means on the vehicle. It is the same. Therefore, the same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.
In the case of this face image pickup device 101, the CCD camera 20 is installed in the lower corner portion near the driver's seat of the rear view mirror 18 in the passenger compartment, and the near infrared LED 21 is located in the vehicle width direction center on the front end side of the ceiling portion. It is installed near the passenger seat. In this embodiment, the CCD camera 20 and the near-infrared LED 21 are both installed above the position of the eyeball 27 of the driver m, but the near-infrared LED 21 is perpendicular to the CCD camera 20. And the vehicle width direction are spaced apart by a predetermined distance or more.

  In this case, as shown in FIG. 7, the predetermined distance in each direction is such that the light emitted from the near-infrared LED 21 reflects the light on the spectacles 25 and the light emitted from the near-infrared LED 21. The distance from the bright spot 28 on the eyeball reflected on the iris of the eyeball 27 is a distance that does not overlap each other when viewed from the CCD camera 20 (imaged by the CCD camera 20).

  In the case of this embodiment, the CCD camera 20 that is an image pickup means is arranged vertically above the position of the eyeball 27 of the driver m seated on the seat 11, and the near-infrared LED 21 that is a light projecting means is a CCD camera. It is arranged so as to be further upward in the vertical direction than 20. Therefore, when the CCD camera 20 images the iris region of the eyeball 27 of the driver m from an obliquely upper side, the near-infrared LED 21 does not appear as a reflected image in the region on the glasses 25 that intersects the imaging range. As a result, as shown in FIG. 7, the image of the near-infrared LED 21 on the spectacles 25 imaged by the CCD camera 20 (the spectacle bright spot 26) deviated above the eyeball 27 (the spectacle bright spot 28). Position.

  Also in this embodiment, it is possible to prevent the bright spot 26 on the eyeglass from overlapping the bright spot 28 on the eyeball and appear on the CCD camera 20, and the face of the driver m is horizontal and vertical with respect to the front of the vehicle. Even when tilted in any direction, it is possible to more reliably prevent the bright spot 26 on the eyeglass and the bright spot 28 on the eyeball from overlapping on the CCD camera 20.

  In addition, this invention is not limited to said embodiment, A various design change is possible in the range which does not deviate from the summary. For example, in the above embodiment, only one near-infrared LED 21 (light projecting means) is installed on either the left or right side of the steering wheel 13 toward the front of the driver's seat. May be provided on the left side as well.

DESCRIPTION OF SYMBOLS 1,101 ... Face image imaging device 13 ... Steering wheel 20 ... CCD camera (imaging means)
21 ... Near-infrared LED (light projection means)
26 ... Bright point on glasses 28 ... Bright point on eyeball

Claims (2)

A steering wheel disposed in front of the driver's seat in the vehicle compartment;
An imaging unit that is disposed on the vehicle front side of the steering wheel in the passenger compartment and that captures a face image of the driver seated in the driver's seat;
A light projecting means for projecting visible light or invisible light toward the eyeball of the driver;
In the vehicular face image capturing apparatus comprising:
The imaging means and the light projecting means are arranged apart from each other by a predetermined distance in the vertical direction and the vehicle width direction,
The predetermined distance includes a bright spot on the spectacles where the light projected by the light projecting means reflects on the spectacles worn by the driver, and the light projected by the light projecting means on the eyeball of the driver. The vehicular face image imaging device is characterized in that the bright spot on the eyeball reflected by the lens is set at a distance that does not overlap when viewed from the imaging means.   The light projecting means is arranged vertically above the imaging means when the imaging means is arranged vertically above the position of the eyeball of the driver seated on the driver seat, and the imaging means 2. The vehicle face according to claim 1, wherein the vehicle face is disposed below the imaging unit in the vertical direction below the eyeball position of the driver seated in the driver's seat. Imaging device.

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