Patent Publication Number: US-2021185797-A1

Title: A driver assist system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a national stage of International Application No. PCT/US18/58883 filed Nov. 2, 2018, the disclosure of which is incorporated herein by reference in its entirety, and which claimed priority [[This application claims priority]] from U.S. Provisional Application Ser. No. 62/581,146 filed Nov. 3, 2017 and U.S. Provisional Application Ser. No. 62/675,287 filed May 23, 2018, the subject matter of which are incorporated herein by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a driver assist system for a vehicle, and, more specifically, to a driver assist system that maintains the position of an image sensor relative to a camera lens. 
     BACKGROUND 
     Vehicle driver assist systems that use a camera to monitor the environment surrounding the vehicle are known. A driver assist system can aid a driver in the operation of a motor vehicle by providing operational information such as a potential collision, lane or roadway departure, location of pedestrians, road sign information, etc. Data from the driver assist system is provided to other vehicle systems to provide the driver with a warning, haptic or tactile feedback, and/or autonomous control of the vehicle. 
     A driver assist system in a vehicle may include a camera that acquires information and provides the acquired information to a vehicle safety system designed to assist the driver. The camera may be mounted in any desired location in the vehicle, such as the vehicle windshield to ensure a desired field of view. The camera includes a lens. An image sensor on a printed circuit board (PCB) senses the image acquired by the lens. The image sensor may move relative to the lens in response to strain on the PCB. Movement of the image sensor relative to the lens may reduce the quality of the image. 
     SUMMARY 
     The present invention is directed to a driver assist system for a vehicle including a housing and a lens having an axial end extending into the housing. A first printed circuit board (PCB) is connected to the housing. The first PCB has a rigid portion and a flexible portion. The rigid portion and the flexible portion extend along a common axis. An image sensor is mounted on the rigid portion of the PCB adjacent the axial end of the lens. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other features and advantages of the present invention will become apparent to one skilled in the art upon consideration of the following description of the invention and the accompanying drawings, in which: 
         FIG. 1  is a schematic view of a driver assist system constructed in accordance with a first embodiment of the present invention; and 
         FIG. 2  is a schematic view of a driver assist system constructed in accordance with a second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a driver assist system  10  constructed in accordance with the present invention. The driver assist system  10  includes a camera  12  having a housing  14 . The housing  14  may have a first portion  16  and a second portion (not shown) connected to the first portion to define an interior of the housing  14 . The first portion  16  of the housing  14  may have an opening  20  through which a lens  22  extends. A first axial end  24  of the lens  22  is fixed to the housing  14 . The first axial end  24  is supported within the housing  14  adjacent an image sensor  26 . A second axial end  28  of the lens  20  extends through the opening  20  out of the housing  14 . 
     The image sensor  26  senses an image acquired by the lens  22  and provides at least one signal to a vehicle safety system to provide a vehicle operator with a warning, haptic or tactile feedback, and/or autonomous control of the vehicle. The image sensor  26  is mounted on an imager or first printed circuit board (PCB)  30 . The first PCB  30  has a first rigid portion  32  and a second rigid portion  34  interconnected by a flexible portion or member  36 . The first portion  34  of the PCB  30  is connected to the housing  14 . The first and second rigid portions  32 ,  34  and the flexible portion  36  extend along a common axis. The first and second rigid portions  32 ,  34  may be coplanar. 
     The image sensor  26  is connected to the first rigid portion  32  of the first PCB  30 . The flexible portion  36  allows the first and second rigid portions  32 ,  34  of the first PCB  30  to move relative to each other. The flexible portion  36  may have a thickness that is less than the thicknesses of the first and second rigid portions  32 ,  34 . It is contemplated that the flexible portion  36  may be formed in one-piece with the first rigid portion  32  and/or the second rigid portion  34 . The flexible portion  36  may be made of any desired material. The second rigid portion  34  of the first PCB  30  is connected to a second or main PCB  40  by a connector  42 . The second PCB  40  is mounted in the housing  14  and extends generally parallel to the first PCB  30 . 
     The first rigid portion  32  of the PCB  30  is connected to the housing  14  in any desired manner, such as by fasteners (not shown) and/or glue. The camera  12  and/or image sensor  26  are focused to provide a desired image quality or clarity. The connector  42  and second PCB  40  are connected to the second rigid portion  34  of the PCB  30  after the camera  12  and/or image sensor  26  are focused. 
     The connector  42  may produce strain on the first PCB  30  that may cause the first PCB to move relative to the housing  14  when the connector  42  is connected to the PCB  30 . The flexible portion  36  of the first PCB  30  minimizes strain on the first portion  32  of the first PCB and, therefore, minimizes strain on the image sensor  26 . The first portion  32  of the first PCB  30  with the image sensor  26  may be considered decoupled from the second portion  34  and the flexible portion  36  of the first PCB that may experience strain. The flexible portion  36  allows the first and second portions  32 ,  34  to move relative to each other. Therefore, relative movement between the lens  22  and the image sensor  26  is minimized. 
       FIG. 2  illustrates a second embodiment of a driver assist system constructed in accordance with the present invention. The driver assist system  110  includes a camera  112  having a housing  114 . The housing  114  may have a first portion  116  connected to a second portion  118  to define an interior of the housing  114 . The first portion  116  of the housing may have an opening  120  through which a lens  122  extends. A first axial end  124  of the lens  122  is connected to the housing  114 . The first axial end  124  is supported within the housing  114  adjacent an image sensor  126 . A second axial end  128  of the lens  122  extends through the opening  120  out of the housing  114 . 
     The image sensor  126  senses an image acquired by the lens  122  and provides at least one signal to a vehicle safety system to provide a vehicle operator with a warning, haptic or tactile feedback, and/or autonomous control of the vehicle. The image sensor  126  is mounted on an imager printed circuit board (PCB)  130 . The PCB  130  has a first rigid portion  132  and a second flexible portion  134 . The image sensor  126  is connected to the first rigid portion  132  of the PCB  130 . The first portion  132  of the PCB  130  is connected to the housing  114 . The rigid portion  132  and the flexible portion  134  are movable relative to each other. The rigid portion  132  and the flexible portion  134  extend along a common axis. The flexible portion  134  may have a thickness that is less than the thicknesses of the rigid portion  132 . It is contemplated that the flexible portion  134  may be formed in one-piece with the first rigid portion  132 . The flexible portion  134  may be made of any desired material. 
     The second flexible portion  134  of the PCB  130  is connected to the first and second portions  116 ,  118  of the housing  114 . The second flexible portion  134  of the PCB  130  has a first side  136  facing the first portion  116  of the housing  114  and a second side  138  facing the second portion  118  of the housing  114 . A first thermal interface material  150  is connected to the first portion  116  of the housing  114  and the first side  136  of the second flexible portion  134 . A second thermal interface material  152  is connected to the second portion  118  of the housing  114  and the second side  138  of the flexible portion  134 . The first and second thermal interface materials  150 ,  152  may be pads, gels and/or pastes that conduct heat from the PCB  130  and the image sensor  126  to the housing  114  for dissipating the heat produced. The flexible portion  134  of the PCB  130  may include exposed copper GND that makes contact with at least one of the first and second thermal interface materials  150 , 152 . Although the first and second thermal interface materials  150 ,  152  are described as being connected to opposite sides of the flexible portion  134 , it is contemplated that thermal interface material may only be connected to one of the first and second sides  136 ,  138  of the flexible portion. 
     The first rigid portion  132  of the PCB  130  is connected to the housing  114  in any desired manner, such as by fasteners (not shown) and/or glue. The camera  112  and/or image sensor  126  are focused to provide a desired image quality or clarity. The thermal interface materials  150 ,  152  are connected to the second flexible portion  134  of the PCB  130  and the housing  114  after the camera  112  and/or image sensor  126  are focused. 
     The first and second thermal interface materials  150 ,  152  may produce strain on the PCB  130  that may cause the PCB to move relative to the housing  114  when the thermal interface materials are connected to the PCB. The flexible portion  134  of the PCB  130  minimizes strain on the first rigid portion  132  of the PCB and, therefore, minimizes strain on the image sensor  126 . The first portion  132  of the PCB  130  with the image sensor  126  may be considered decoupled from the second portion  134  of the PCB that may experience strain. The flexible portion  134  of the PCB  130  may move relative to the rigid portion  132 . Therefore, relative movement between the lens  122  and the image sensor  126  is minimized. 
     From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications. Although the first PCB  30  of the embodiment shown in  FIG. 1  is described as having first and second rigid portions  32 , 34  interconnected by a flexible portion  36 , it is contemplated that the first PCB may only have one rigid portion to which the image sensor  26  is connected and a flexible portion connected to the second PCB  40  by the connector  32 , similar to the embodiment of  FIG. 2 . Also, the PCB  130  of the embodiment of shown in  FIG. 2  may have first and second rigid portions interconnected by a flexible portion with the first rigid portion connected to the image sensor  126  and the second rigid portion connected to the thermal interface materials  150 ,  152 , similar to the embodiment of  FIG. 1 . Such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims.