Image capture device and vehicle comprising such an image capture device

An image capture device having a housing containing a first image capture apparatus configured to acquire images in a first wavelength range, the first image capture apparatus being a thermal camera or a thermal photographic apparatus, a second image capture apparatus configured to acquire images in a second wavelength range disjoint from the first wavelength range, and an illumination system for emitting radiation in the second wavelength range. The image capture device includes a thermal isolation partition interposed between the first image capture apparatus and the illumination system so as to thermally isolate the first image capture apparatus from the illumination system.

TECHNICAL FIELD

The present invention relates to an image capture device, in particular an image capture device comprising a first image capture apparatus and a second image capture apparatus configured to acquire images in separate wavelength ranges.

BACKGROUND

US20180302564A1 discloses an image capture device comprising a thermal camera configured to acquire images in the far-infrared and/or mid-infrared range, an NIR (acronym of near-infrared) camera configured to acquire images in the near-infrared range, and an illumination system to illuminate the scene with radiation in the near-infrared range.

SUMMARY

One object of the invention is to provide an image capture device that is easy to integrate into a more complex system, and reliable.

To this end, at least one aspect of the invention provides an image capture device for capturing images of a scene within a field of view of the image capture device, the image capture device comprising a housing within which are positioned a first image capture apparatus configured to acquire images in a first wavelength range, the first image capture apparatus being a thermal camera or a thermal photographic apparatus, a second image capture apparatus configured to acquire images in a second wavelength range separate from the first wavelength range, and an illumination system comprising at least one radiation source and configured to emit radiation, from each radiation source, in the second wavelength range, the image capture device further comprising a thermal isolation partition positioned within the housing and interposed between the first image capture apparatus and the illumination system so as to thermally isolate the first image capture apparatus from the illumination system.

The grouping of the first image capture apparatus, the second image capture apparatus, and the lighting system in a single housing provides the image capture device as a unit that can be easily integrated into a vehicle.

The arrangement of the thermal partition between the lighting system and the first image capture apparatus reduces the risk of disturbance of the first image capture apparatus by the lighting system, in particular by heat emitted by the lighting system.

According to particular embodiments, the image capture device comprises one or more of the following optional features, taken individually or in any technically possible combination:the second image capture apparatus is positioned within the housing by being interposed between the first image capture apparatus and the lighting system;the thermal isolation partition is positioned within the housing and interposed between the second image capture apparatus and the illumination system;the first wavelength range is within a wavelength band between 1.4 μm and 1,000 μm;the second image capture apparatus is a near infrared photographic photographic apparatus or a near infrared camera;the second wavelength range is within a wavelength band between 0.750 μm and 1.4 μm;the illumination system is configured not to emit radiation within the first wavelength range using with each radiation source;each radiation source is a light emitting diode.

The invention also relates to a vehicle, in particular a motor vehicle, equipped with an image capture device as defined above.

DETAILED DESCRIPTION

As illustrated in the FIGURE, an image capture device2is configured to acquire images of a scene located in a field of view FV. The image capture device2has an axis of view A, with the field of view FV centered on the axis of view A.

The image capture device2includes a housing4containing a first image capture apparatus6, a second image capture apparatus8, an illumination system10, and a thermal isolation partition12.

The first image capture apparatus6and the second image capture apparatus8are each arranged to capture images of the scene, substantially along the viewing axis A.

The first image capture apparatus6is a photographic apparatus or a camera, for example. The second image capture apparatus8is a photographic apparatus or a camera, for example.

An “image capture apparatus configured to acquire images in a wavelength range” means an image capture apparatus configured to acquire images from electromagnetic radiation (or “radiation” hereinafter) that has a wavelength within said wavelength range.

The first image capture apparatus6is configured to acquire images in a first wavelength range.

In one exemplary embodiment, the first image capture apparatus6is a thermal camera or a thermal photographic apparatus.

In one exemplary embodiment, the first wavelength range is in the far infrared range, i.e., wavelengths between 8 μm and 1,000 μm, and/or in the mid-infrared range, i.e., wavelengths between 1.4 μm and 8 μm.

In one particular exemplary embodiment, the first wavelength range is between 5 μm and 7 μm.

Radiation in the far infrared and mid infrared range, particularly in the wavelength band specified above, is radiation known as “thermal”.

Thermal radiation is emitted spontaneously, especially by people.

The detection of thermal radiation emitted by a person allows the presence of this person to be determined, and may allow this person's physiological state to be determined, for example, by analyzing the intensity of the thermal radiation and/or the distribution of the thermal radiation as a function of its intensity on at least one part of the person's body, in particular the face.

The second image capture apparatus8is configured to acquire images in a second wavelength range separate from the first wavelength range.

Preferably, the wavelengths in the second wavelength range are smaller than those in the first wavelength range.

In one exemplary embodiment, the second image capture apparatus8is a near infrared photographic apparatus or a near infrared camera.

In one exemplary embodiment, the second wavelength range is in the near infrared range, i.e., wavelengths between 0.750 μm and 1.4 μm.

In one particular exemplary embodiment, the second wavelength range is between 0.850 μm and 0.940 μm.

The illumination system10comprises one or more radiation source(s)14, with the illumination system10configured so that each radiation source14emits radiation in the second wavelength range.

The illumination system10is configured for illumination of the scene by each radiation source14generating radiation in the second wavelength range, so as to enable acquisition of images of the scene in the second wavelength range by the second image capture apparatus8.

Objects, and in particular people, spontaneously emit little or no radiation in a range such as the near-infrared or visible range. Illumination of the scene by the illumination system10allows for the capture of images of the scene in the second wavelength range, using the second image capture apparatus8.

Illumination of the scene in the second wavelength range included in the non-visible, near-infrared range allows the scene to be illuminated in a wavelength range in which a person in the scene has little or no sensitivity, thereby avoiding disturbance to that person.

Preferably, the lighting system10is configured such that each radiation source14does not emit radiation in the first wavelength range.

This prevents the radiation emitted by each radiation source14from being detected by the first image capture apparatus6.

In particular, preferably, the illumination system10is configured such that each radiation source14emits radiation only in the second wavelength range.

In one exemplary embodiment, each radiation source14is for example a light emitting diode (or LED).

In a manner known per se, the wavelength of the radiation emitted by each radiation source14provided in the form of a light emitting diode depends in particular on the radiation source itself and the supply current during operation.

The thermal isolation partition12is arranged inside the housing4with being interposed between the first image capture apparatus6and the lighting system10.

Thus, the first image capture apparatus6is separated from the lighting system10by the thermal isolation partition12, which makes it possible to protect the first image capture apparatus6from the heat generated by the lighting system10during operation of the latter. This heat is generated by a power supply electronics of each radiation source14, for example, and/or by each radiation source14.

The thermal isolation partition12is for example attached to the interior of the housing4.

The thermal isolation partition12is for example made of a material different from a material the housing4is made of.

Advantageously, the heat isolation partition12is made of a material having a low thermal conductivity, in particular a lower thermal conductivity than the material that the housing4is made of.

In one exemplary embodiment, the housing4is made of metal, in particular aluminum or magnesium.

In one exemplary embodiment, the thermal isolation partition12is made of a thermal isolation material, in particular a thermal isolation material formed of fibers, such as fibers marketed under the Nomex® brand name.

In a variant, the thermal isolation partition12is made of the same material as the housing4.

In one particular embodiment, the thermal isolation partition12is made in one piece of material with the housing4.

Preferably, the second image capture apparatus8is positioned inside the housing4while also being interposed between the first image capture apparatus6and the lighting system10.

Thus, the first image capture apparatus6is separated from the lighting system10both by the thermal isolation partition12and by the second image capture apparatus8.

This protects the first image capture apparatus6from heat generated by the illumination system10, due to the fact that the first image capture apparatus6is spaced from the illumination system10within the housing4, and the second image capture apparatus8and the thermal isolation partition12are interposed between the first image capture apparatus6and the illumination system10.

Preferably, the first image capture apparatus6, the second image capture apparatus8, the thermal isolation partition12, and the illumination system10are aligned along an alignment direction E, with the second image capture apparatus8and the thermal isolation partition12located between the first image capture apparatus6and the illumination system10.

The alignment direction E is perpendicular to the viewing axis A of the image capture device2.

Preferably, and as illustrated inFIG.1, the thermal isolation partition12is positioned between the second image capture apparatus8and the illumination system10.

Thus, the second image capture apparatus8is also thermally isolated from the lighting system10by the thermal isolation partition12.

In the preferred embodiment, the first image capture apparatus6, the second image capture apparatus8, the thermal isolation partition12, and the illumination system10are arranged within the housing4, aligned in this order along the alignment direction E.

The second image capture apparatus8is interposed between the first image capture apparatus6and the illumination system10, the thermal isolation partition12being further interposed between the second image capture apparatus8and the illumination system10.

The housing4defines an inner space16within which the first image capture apparatus6, the second image capture apparatus8, the lighting system10, and the thermal isolation partition12are received.

In the illustrated embodiment, the thermal isolation partition12delimits a first compartment18and a second compartment20within the housing4, thermally isolated from each other by the thermal isolation partition12.

The first image capture apparatus6is received in the first compartment18, with the lighting system10received in the second compartment20.

The second image capture apparatus8is for example received in the first compartment18, preferably interposed between the first image capture apparatus6and the thermal isolation partition12.

The thermal isolation partition12isolates the first image capture apparatus6from the thermal radiation of the lighting system10.

Advantageously, the thermal isolation partition12separates the first compartment18and the second compartment20in a sealed manner. Thus, the thermal isolation partition12prevents heat generated by the lighting system10from spreading by convection from the second compartment20in which the lighting system10is located to the first compartment18in which the first image capture apparatus6is located.

The housing4has a front face22facing the field of view FV of the image capture device2, with the first image capture apparatus6and the second image capture apparatus8positioned within the housing4configured to capture images of the scene from this front face22, and the lighting system10configured to illuminate the scene from this front face22.

In one exemplary embodiment, the front face22comprises one or more apertures24, with each of the first image capture apparatus6, the second image capture apparatus8, and the illumination system10being positioned opposite a related aperture24to capture images of the scene through the related aperture24or illuminate the scene through the related aperture24, as appropriate.

In one exemplary embodiment, one respective aperture24is provided for each of the first image capture apparatus6, the second image capture apparatus8and the illumination system10.

In a variant, one aperture24is associated with at least two of the first image capture apparatus6, the second image capture apparatus8and the lighting system10.

In a particular example, the front face22comprises a common aperture24associated with the first image capture apparatus6, the second image capture apparatus8and the lighting system10.

In operation, the first image capture apparatus6captures images of the scene in front of the image capture device2in the first wavelength range. The illumination system10illuminates the scene with radiation emitted from each radiation source14. The second image capture apparatus8captures images of the scene illuminated by the illumination system10in the second wavelength range.

Preferably, the radiation emitted by the lighting system10is outside the first wavelength range, so that the first image capture apparatus6is not disturbed by the radiation emitted by each radiation source of the lighting system10.

The arrangement of the various elements within the housing4(first image capture apparatus6, second image capture apparatus8, lighting system10and the thermal isolation partition12) allows the first image capture apparatus6to be protected from the heat emitted by the lighting system10during its operation, and which could disturb the operation of the first image capture apparatus6.

The arrangement of the various components attached within a single housing4provides an image capture device2that can be handled as a single unit. This makes it easier to assemble and connect it to a more complex system.

The first image capture apparatus6and the second image capture apparatus8are fixed in the same housing4in predetermined relative positions, which facilitates image processing when matches need to be made between images captured by the first image capture apparatus6and the second image capture apparatus8.

The image capture device2equips a vehicle26, for example, such as a motor vehicle26.

In one exemplary embodiment, the image capture device2is arranged such that the scene is located inside the vehicle26, and in particular such that the scene includes the passenger compartment of the vehicle26.

Such an image capture device2can for example detect the presence of occupants in the passenger compartment and/or detect each occupant's physiological state by analysis of the captured images, for example based on the thermal radiation emitted by each occupant and its distribution on at least a part of the body of each occupant, for example on the face of each occupant.

In one exemplary embodiment, a detection system28comprises the image capture device2and a processing module30configured to automatically process images captured by the image capture device2.

The processing module30is configured to analyze the images captured by the image capture device2, for example, namely the images captured by the first image capture apparatus6and the images captured by the second image capture apparatus8.

The processing module30is for example a software application stored in a memory32of a data processing unit34and executable by a processor36of the data processing unit34. In a variant, the processing module30is provided in the form of a specific integrated circuit or programmable logic circuit.

The invention is not limited to the example embodiments described above and illustrated in the drawing, as other example embodiments are conceivable.

In the illustrated example embodiment, the thermal isolation partition12is interposed between the lighting system10and the second image capture apparatus8.

In a variant, as shown in dotted line inFIG.1, the thermal isolation partition12is interposed between the first image capture apparatus6and the second image capture apparatus8. This still protects the first image capture apparatus6from the heat emitted by the lighting system10.

In another variant, the image capture device2comprises two thermal isolation partitions12, one interposed between the first image capture apparatus6and the second image capture apparatus8(dotted line inFIG.1), and the other interposed between the second image capture apparatus8and the lighting system10.

The first image capture apparatus6is then separated from the lighting system10by the second image capture apparatus8and two thermal isolation partitions12.

The second image capture apparatus8is then for example located in an intermediate compartment located between the two thermal isolation partitions12.