Optical sensor device to be installed on board a motor-vehicle for aid in driving and/or for automatic activation of systems provided on the motor-vehicle

• US 20070090311A1
• Filed: 09/18/2006
• Published: 04/26/2007
• Est. Priority Date: 10/21/2005
• Status: Active Grant

• Current Assignee: C.R.F. Societa Consortile Per Azioni
• Original Assignee: C.R.F. Societa Consortile Per Azioni
• Inventors: Pallaro, Nereo
• Granted Patent: US 7,365,303 B2
• Time in Patent Office: Days
• US Class Current: 250/574
• CPC Class Codes: B60Q 1/1423 Automatic dimming circuits, i.e. switching between high beam and low beam due to change of ambient light or light level in road traffic
• CPC Class Codes: B60R 1/00 Optical viewing arrangements; Real-time viewing arrangements for drivers or passengers using optical image capturing systems, e.g. cameras or video systems specially adapted for use in or on vehicles
• CPC Class Codes: B60R 2300/106 using night vision cameras
• CPC Class Codes: B60R 2300/108 using 'non-standard' camera systems, e.g. camera sensor used for additional purposes i.a. rain sensor, camera sensor split in multiple image areas
• CPC Class Codes: B60R 2300/8053 for bad weather conditions or night vision
• CPC Class Codes: B60R 2300/8093 for obstacle warning
• CPC Class Codes: B60S 1/0822 characterized by the arrangement or type of detection means
• CPC Class Codes: B60S 1/0844 including a camera
• CPC Class Codes: B60S 1/0885 the sensor being integrated in a rear-view mirror module
• CPC Class Codes: B60S 1/0888 characterized by the attachment of the elements in a unit
• CPC Class Codes: G01J 1/02 Details
• CPC Class Codes: G01J 1/0271 Housings; Attachments or accessories for photometers
• CPC Class Codes: G01J 1/04 Optical or mechanical part supplementary adjustable parts
• CPC Class Codes: G01J 1/0411 using focussing or collimating elements, i.e. lenses or mirrors; Aberration correction
• CPC Class Codes: G01J 1/0437 using masks, aperture plates, spatial light modulators, spatial filters, e.g. reflective filters
• CPC Class Codes: G01J 1/4228 arrangements with two or more detectors, e.g. for sensitivity compensation
• CPC Class Codes: G01N 2021/4709 Backscatter
• CPC Class Codes: G01N 21/538 for determining atmospheric attenuation and visibility
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver
• CPC Class Codes: G06V 20/56 exterior to a vehicle by using sensors mounted on the vehicle
• CPC Class Codes: H04N 23/55 : Optical parts specially adapted for electronic image sensors; Mounting thereof

Abstract

An optical sensor device that can be installed on board a motor vehicle for aid to driving and/or for automatic activation of one or more on-board systems according to the environmental conditions detected comprises a sensor module including an array of the CCD or CMOS type, the sensitive area of which is split into sub-areas dedicated to different functions, which are separate from one another and set at a distance apart, and located adjacent to the four vertices of the sensitive area of the array.

Claims

1. An optical sensor device of the type comprising:

an optical sensor in the form of CCD or CMOS array, having a sensitive area in which a number of sub-areas is defined, each designed for a specific optical function corresponding to monitoring of the scene in front of the motor vehicle and/or to detection of environmental parameters; and

a plurality of optical systems with different directions of the optical axis and/or fields of vision, designed to send optical signals to respective sub-areas of the sensitive area of said array in order to perform the aforesaid functions,

in which at least some of said sub-areas are defined by different and separate portions of the sensitive area of said array dedicated to different optical functions, and

in which said different and separate portions of the sensitive area of the array include at least;

a first portion of the top part of the sensitive area, defining a first sub-area for detection of fog in front of the motor vehicle;

a second and different portion of the sensitive area, defining a second sub-area, for detection of a twilight condition;

a bottom portion of the sensitive area, defining a third sub-area, separated from said first sub-area and from said second sub-area, for monitoring the scene in front of the motor vehicle;

a further portion of the top part of the sensitive area, defining a fourth sub-area different and separate from the first, second and third sub-areas, for detecting the presence of raindrops or mist on the windscreen or on the rear window of the motor vehicle;

a first optical system for conveying optical signals on said first sub-area for detection of fog, including a light emitter for emitting light in the direction of the space in front of the motor vehicle, a receiver for receiving light scattered by the fog possibly present in front of the motor vehicle, and optical means for directing the light received only on said first sub-area of the sensitive area of said array; and

a second optical system, a third optical system and a fourth optical system provided for directing optical signals on said second, third and fourth sub-areas of the sensitive area of said array, respectively for detection of a twilight condition, for monitoring the scene in front of the motor vehicle, with particular reference to a condition in which the vehicle crosses another vehicle coming in the opposite direction or to a condition of passing through a tunnel, and for detection of raindrops or of mist on the window of the motor vehicle,

said optical sensor device being characterized in that;

said first, second, third and fourth sub-areas of the sensitive area of the array occupy portions that are separate and at a distance from one another of the sensitive area of the array, adjacent, respectively, to four different vertices of the sensitive area of the array;

said array is supported by a plate forming part of a sensor module incorporating at least part of the aforesaid optical systems;

said sensor module is mounted within a supporting structure;

said supporting structure supports the aforesaid emitter dedicated to the function of detecting fog, and a further emitter dedicated to the function of detecting rain and/or mist on the window of the motor vehicle;

the optical system receiving the radiation scattered by the fog is oriented according to an axis directed upwards and towards a side of the motor vehicle, not orthogonal to the windscreen, according to a cone that crosses the cone of lighting of the emitter in an area located beyond the windscreen;

the optical system designed for the function of front monitoring comprises at least one lens having an optical axis parallel to the direction of travel;

the optical system for detection of the twilight condition comprises an optical fibre with a front end oriented upwards and on a side with respect to the direction of travel of the vehicle, and a rear end, associated to which is a lens for causing the outcoming light beam to converge on the respective sub-area of the array; and

the optical system for detection of rain or mist on the window of the motor vehicle comprises, at one end, a lens facing the window of the motor vehicle, having its optical axis perpendicular to the window, and, at the other end, a lens having its optical axis orthogonal to the array, and optical means set between said lenses for deflecting the beam coming from the first lens towards the second lens,

the aforesaid optical components being mounted within a support fixed on said rear plate bearing the array that constitutes therewith the aforesaid sensor module.

2. The sensor device according to claim 1, wherein, downstream of the lens for detection of fog, an optical filter and one or more diaphragms are provided.

3. The sensor device according to claim 1, wherein, downstream of the aforesaid at least one lens for detection of crossing another vehicle proceeding in the opposite direction and of passing through a tunnel, are set a further lens and a diaphragm for limiting the cross section of the beam coming from the optical system that is directed towards the respective sub-area of the array, a further diaphragm being set between the two lenses.

4. The sensor device according to claim 1, wherein the aforesaid lens associated to the rear end of the optical fibre is a biconvex lens.

5. The sensor device according to claim 1, wherein the emitter devices used for the function of detecting fog and for the function of detecting raindrops or mist on the window of the motor vehicle are constituted by LED sources in the near infrared.

6. The sensor device according to claim 1, wherein the supporting structure of the sensor module comprises two separate supporting plates, screwed together and to the rear plate bearing the sensor array, a first of said supporting plates carrying the optics for monitoring front visibility, the rear lens for the rain function, and the focusing lens associated to the optical fibre for detection of the twilight condition, the second supporting plate carrying the remaining optical components and incorporating, in particular, a casing for the optical system dedicated to detection of rain, which comprises, in addition to the aforesaid first lens, two further lenses set in series downstream of the first lens, and a total-internal-reflection prism that deflects the beam coming from said further lenses towards the aforesaid lens at the end of the system facing the array of the sensor.

7. The sensor device according to claim 6, wherein set between the rear plate bearing the array and the aforesaid supporting plates are spacers selected for focusing of the system.

8. The sensor device according to claim 1, wherein the optical system for the function of detecting crossing of another vehicle proceeding in the opposite direction comprises an optical microzoom.

9. The sensor device according to claim 1, wherein the aforesaid array is of the CMOS type with logarithmic response.

10. The sensor device according to claim 1, wherein the array is of the colour-CMOS type.

11. The sensor device according to claim 1, wherein it is associated to an electronic control unit designed to activate automatically one or more on-board systems of the motor vehicle as a function of the signals received from said sensor device.