VEHICULAR WINDSHIELD-MOUNTED FORWARD VIEWING CAMERA WITH COATED STRAY LIGHT SHIELD REGION OF HOUSING

A vehicular camera module configured to be disposed at an in-cabin side of a windshield of a vehicle includes a housing and a camera disposed at the housing. The camera includes an imager having a two dimensional array of at least one million photosensing elements arranged in rows and columns. The camera includes a lens. With the vehicular camera module disposed at the in-cabin side of the windshield, the camera views through the windshield and forward of the vehicle. The vehicular camera module includes a glare shield region below and forward of the lens of the camera. The glare shield region includes a planar surface that is coated with a light absorbing coating. The coated glare shield region, with the vehicular camera module disposed at the in-cabin side of the windshield, reduces glare light incident at the lens of the camera.

FIELD OF THE INVENTION

The present invention relates generally to a vehicular vision system and, more particularly, to a vehicular vision system that utilizes a forward viewing windshield-mounted camera.

BACKGROUND OF THE INVENTION

Use of imaging sensors in vehicle imaging systems is common and known. Examples of such known systems, with forward viewing cameras mounted at and behind the vehicle windshield, are described in U.S. Pat. Nos. 9,871,971 and/or 9,596,387, which are hereby incorporated herein by reference in their entireties.

SUMMARY OF THE INVENTION

The present invention provides a driver assistance system or vision system or imaging system for a vehicle that utilizes a windshield-mounted forward viewing camera to capture image data representative of images exterior and forward of the vehicle. The camera comprises a lens and an imager having a two dimensional array of photosensing elements. The windshield-mounted camera module includes a stray light shield or glare shield disposed below and in front of the imager and lens. The stray light shield or glare shield comprises a light absorbing coating or film applied at a non-contoured or non-ribbed surface of the housing of the camera module that is disposed below and in front of the camera. The light absorbing coating is applied or painted onto the surface of the housing at a light shielding region to limit glare light incident at the light shielding region from reflecting to the lens of the camera.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A vehicle vision system and/or driver assist system and/or object detection system and/or alert system operates to capture images exterior of the vehicle and may process the captured image data to display images and to detect objects at or near the vehicle and in the predicted path of the vehicle, such as to assist a driver of the vehicle in maneuvering the vehicle in a rearward direction. The vision system includes an image processor or image processing system that is operable to receive image data from one or more cameras and provide an output to a display device for displaying images representative of the captured image data. Optionally, the vision system may provide display, such as a rearview display or a top down or bird's eye or surround view display or the like.

Referring now to the drawings and the illustrative embodiments depicted therein, vision system10for a vehicle12includes at least one windshield-mounted camera module14comprising an exterior viewing imaging sensor or camera18, such as a forward viewing imaging sensor or camera, which may be disposed at and behind the windshield16of the vehicle12and viewing forward through the windshield16so as to capture image data representative of the scene occurring forward of the vehicle12(FIG. 1). Optionally, the vision system10may include multiple exterior viewing imaging sensors or cameras, such as a forward viewing camera at the front of the vehicle12, and a sideward/rearward viewing camera at respective sides of the vehicle12, and a rearward viewing camera at the rear of the vehicle12, which capture images exterior of the vehicle12. The camera or cameras each include a lens for focusing images at or onto an imaging array or imaging plane or imager of the camera.

As shown inFIGS. 1 and 2, the windshield-mounted camera module14includes the forward viewing camera18(having a lens20that focuses or images light onto an imager of the camera18). With the camera module14disposed at the windshield16of the vehicle12, the forward viewing camera18views through the windshield16and forward of the vehicle12, such as for a machine vision system (such as for traffic sign recognition, headlamp control, pedestrian detection, collision avoidance, lane marker detection and/or the like). The vision system10includes a control or electronic control unit (ECU)19having electronic circuitry and associated software. The electronic circuitry includes a data processor or image processor that is operable to process image data captured by the camera18or cameras, whereby the ECU19may detect or determine the presence of objects or the like and/or the system provide displayed images at a display device for viewing by the driver of the vehicle. For example, a control and/or display device may be disposed at or be part of or incorporated in or at an interior rearview mirror assembly20of the vehicle, or the control and/or the display device may be disposed elsewhere at or in the vehicle. The data transfer or signal communication from the camera18to the ECU19may comprise any suitable data or communication link, such as a vehicle network bus or the like of the equipped vehicle.

The camera module14and forward viewing camera18is installed in the upper center of the vehicle windshield16. From this vantage point, the camera18captures image data representative of the view through the windshield16and at least forward of and in front of the vehicle12. The image data captured by the camera18is then processed by intelligent algorithms for object detection, such as for detecting vehicles, pedestrians, road markings, traffic signs and other such information of interest ahead of the vehicle and/or in the field of view of the camera. The camera module14includes a stray light shield24disposed below and in front of the camera18and lens20. The stray light shield24may comprise a portion of the housing26of the camera module14(that houses circuitry and part of the camera18, with the lens20protruding through an aperture in the housing26) and may be integrally formed with the housing26. Optionally, the stray light shield24may comprise a separately formed and detachably attached stray light shield24that is attached at the housing26below and in front of the camera18.

Use of a stray light shield24with the forward facing camera18is designed to eliminate light reflections caused by dashboard, camera housing, interior infotainment displays, mounting features and similar factors. The stray light shield24is designed to eliminate as much light reflections as possible of incoming light (including visible and/or infrared or near infrared light, depending on the particular application and spectral sensitivity of the camera). Typical stray light shields include specific or complex ribbed or structured designs and different types of plastic material with a flock sheet or flock paper adhesively applied to the housing.

The stray light shield24of the present invention comprises a plastic (or any other suitable material, such as metal, such as aluminum or other suitable metallic material) component including a coated surface25. The coated surface25is coated with a material that provides a light absorption property and absorbs light incident at the stray light shield24to reduce, limit, or minimize glare light from reaching the camera lens20and the imager of the camera18. The coated surface25of the housing26(seeFIG. 3) provides for light absorption via the material properties of the coating or film, such as via nano-structures of the coating or film. The coating of the coated surface25may be painted or coated onto the surface of the housing26(optionally a thin film may be applied or adhered to the surface of the housing26). As shown inFIG. 3, the coated surface or region of the coated surface25comprises a generally planar region in front and below the camera lens20and side regions that extend upward from the coated planar region.

The light absorbing shield and coated surface25portion of the housing26thus provides the stray light shield24with light absorption properties without any specific surface geometry such as a geometrical arrangement of ribs (such as described in U.S. Pat. No. 9,871,971, which is hereby incorporated herein by reference in its entirety) and without any additional or separately formed sheet material. Thus, the housing26of the camera module14may be formed via injection molding of any suitable plastic or polymeric material (or metal material), and the shield area or portion of the housing may provide a smooth or non-ribbed surface, and the coating may be painted onto or applied at the shield area to provide the stray light shield. The vehicular camera module14, when disposed at the in-cabin surface of the windshield16, makes intimate contact with the windshield surface at least partially around a periphery of the stray light shield24, and includes a cover element that is disposed at and surrounds the housing26and the stray light shield24at the windshield16.

The coating at the coated surface25can be painted onto or applied at any suitable substantially flat or planar (non-ribbed) surfaces of the metal or plastic camera housing26. The usage of such coatings (traditionally used in military or aerospace) at the camera housing26provides a simpler stray light shield24that can be readily established via a simpler injection mold of the housing26and a painting process (such as a spraying or depositing process) after the housing26is formed. The coating at the coated surface25comprises a light absorbing coating that provides enhanced light absorption from all angles. A preferred coating may comprise a plurality of nano-structures or generally vertical tubes deposited or painted onto a generally horizontal surface or region using a chemical vapor deposition process. When light is incident at a such a coated or painted or deposited surface, instead of reflecting off, the light is continually deflected amongst the tubes, eventually becoming absorbed and dissipating into heat. For example, the coating may be similar to the types of coatings available from Surrey NanoSystems Ltd of the United Kingdom under the name VANTABLACK®. VANTABLACK absorbs up to 99.965% of visible light and can be created at around 400 degrees C. (752 degrees F.). The outgassing and particle fallout levels of VANTABLACK are low compared to similar substances. VANTABLACK also has greater resistance to mechanical vibration, and has greater thermal stability, than other similar substances or coatings.

Therefore, the present invention provides a windshield-mounted camera module14that includes a glare shield24(i.e., stray light shield24) that comprises a coated surface25of the housing26of the camera module14. The camera module14thus may be formed via any suitable manner, and does not require complex ribs or undulating structure at the stray light shield area. Instead, the housing26may be formed with a smooth or generally smooth or non-contoured stray light shield24, and then, after the housing26is formed, the stray light shield24is coated or painted with the light absorbing material to provide a stray light shield24with a coated surface25at and in front of and below the camera18of the camera housing26. Accordingly, the coated surface25of the stray light shield25within the camera module14disposed at the in-cabin side of the windshield16reduces glare light incident at the lens20of the camera18.

The windshield16of the vehicle12may include contrasting regions. For example, the windshield16includes a blackout region and a light-transmitting window through the blackout region. With such windshields16, the camera module14is disposed at the in-cabin side such that the camera18views through the windshield16at the light-transmitting window.

The forward viewing camera18may be disposed at a windshield electronics module (WEM) or the like. The forward viewing camera18may comprise an imager having a two-dimensional array of at least one million photosensing elements arranged in rows and columns. The forward viewing camera18may utilize aspects of the systems described in U.S. Pat. Nos. 8,256,821; 7,480,149; 6,824,281 and/or 6,690,268, and/or U.S. Publication Nos. US-2015-0327398; US-2015-0015713; US-2014-0160284; US-2014-0226012 and/or US-2009-0295181, which are all hereby incorporated herein by reference in their entireties.

The vision system10includes an image processor operable to process image data captured by the camera18or cameras, such as for detecting objects or other vehicles or pedestrians or the like in the field of view of one or more of the cameras18. The camera module may include a primary circuit board housed in the housing26(and electrically connected to the imager or imager circuit board via a flexible electrical connector), with the primary circuit board having a processor for processing image data captured by the forward viewing camera18. For example, the image processor may comprise an image processing chip selected from the EYEQ™ family of image processing chips available from Mobileye Vision Technologies Ltd. of Jerusalem, Israel, and may include object detection software (such as the types described in U.S. Pat. Nos. 7,855,755; 7,720,580 and/or 7,038,577, which are hereby incorporated herein by reference in their entireties), and may analyze image data to detect vehicles and/or other objects.

Responsive to such image processing, and when an object or other vehicle is detected, the vision system10may generate an alert to the driver of the vehicle12and/or may generate an overlay at the displayed image to highlight or enhance display of the detected object or vehicle, in order to enhance the driver's awareness of the detected object or vehicle or hazardous condition during a driving maneuver of the equipped vehicle12.