Patent Publication Number: US-2023136351-A1

Title: Camera system laminated into glass using microsensor and lens

Description:
INTRODUCTION 
     The subject disclosure relates to camera systems in vehicles and, in particular, to a camera system that is embedded within a window of the vehicle. 
     A vehicle can employ an on-board camera system that provides an image of its surrounding environment. The image can be provided for various reasons, such as for safety reasons or, in the case of an autonomous vehicle, for use in navigation of the vehicle. Typically, a camera is placed in the interior cabin of the vehicle and up against a window or windshield of the vehicle. Such camera systems require a certain amount of packaging space for the camera as well as the need for a visible opening through the window for the camera to see through. Accordingly, it is desirable to provide a camera system with smaller packaging space and which is not reliant on the visible opening. 
     SUMMARY 
     In one exemplary embodiment, a lens assembly is disclosed. The lens assembly include an image sensor disposed in a gap between a first glass layer and a second glass layer, and a lens disposed in the gap for focusing light passing through one of the first glass layer and the second glass layer onto the image sensor. 
     In addition to one or more of the features described herein, the lens is supported in the gap at a separation distance from the image sensor. The image sensor includes a plurality of image sensors and the lens includes a plurality of lenses, each of the plurality of lenses corresponding to a respective one of the plurality of image sensors. The lens assembly further includes a lens film, wherein the lens is formed in the lens film and the lens film is supported in the gap by one of an optical bonding material between the first glass layer and the second glass layer and a structure disposed between the first glass layer and the second glass layer. The lens assembly further includes an optical bonding layer between the first glass layer and the second glass layer, wherein a portion of the optical bonding layer is disposed between the lens and the image sensor to maintain a separation distance between the lens and the sensor. The lens assembly further includes an optical bonding layer between the first glass layer and the second glass layer, the optical bonding layer forming a hollow chamber between the first glass layer and the second glass layer. The lens assembly of claim  1 , further comprising an LED disposed in the gap, another lens in the gap for dispersing light from the LED and a film in the gap transmissive at infrared wavelengths. 
     In another exemplary embodiment, a window for a vehicle is disclosed. The window includes a first glass layer, a second glass layer separated from the first glass layer by a gap, an image sensor disposed in the gap, and a lens disposed in the gap for focusing light passing through one of the first glass layer and the second glass layer onto the image sensor. 
     In addition to one or more of the features described herein, the lens is supported in the gap at a separation distance from the image sensor. The image sensor includes a plurality of image sensors and the lens includes a plurality of lenses, each of the plurality of lenses corresponding to a respective one of the plurality of image sensors. The window further includes a lens film, wherein the lens is formed in the lens film and the lens film is supported in the gap by one of an optical bonding material between the first glass layer and the second glass layer; and a structure disposed between the first glass layer and the second glass layer. The window further includes an optical bonding layer between the first glass layer and the second glass layer, wherein a portion of the optical bonding layer is disposed between the lens and the image sensor to maintain a separation distance between the lens and the sensor. The window further includes an optical bonding layer between the first glass layer and the second glass layer, the optical bonding layer forming a hollow chamber between the first glass layer and the second glass layer. The window further includes an LED disposed in the gap, another lens in the gap for dispersing light from the LED and a film in the gap transmissive at infrared wavelengths. 
     In yet another exemplary embodiment, a vehicle is disclosed. The vehicle includes a window having a first glass layer and a second glass layer separated from the first glass layer by a gap, an image sensor disposed in the gap, and lens disposed in the gap for focusing light passing through one of the first glass layer and the second glass layer onto the image sensor. 
     In addition to one or more of the features described herein, the image sensor includes a plurality of image sensors and the lens includes a plurality of lenses, each of the plurality of lenses corresponding to a respective one of the plurality of image sensors. The vehicle further includes a lens film, wherein the lens is formed in the lens film and the lens film is supported in the gap by one of an optical bonding material between the first glass layer and the second glass layer; and a structure disposed between the first glass layer and the second glass layer. The vehicle further includes an optical bonding layer between the first glass layer and the second glass layer, wherein a portion of the optical bonding layer is disposed between the lens and the image sensor to maintain a separation distance between the lens and the sensor. The vehicle further includes an optical bonding layer between the first glass layer and the second glass layer, the optical bonding layer forming a hollow chamber between the first glass layer and the second glass layer. The vehicle further includes an LED disposed in the gap, another lens in the gap for dispersing light from the LED and a film in the gap transmissive at infrared wavelengths. 
     The above features and advantages, and other features and advantages of the disclosure are readily apparent from the following detailed description when taken in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features, advantages and details appear, by way of example only, in the following detailed description, the detailed description referring to the drawings in which: 
         FIG.  1    shows a vehicle, in an exemplary embodiment; 
         FIG.  2    shows a side sectional view through a window of the vehicle and a camera system embedded therein, in an embodiment; 
         FIG.  3    shows a side sectional view through the window and the camera system in another embodiment; 
         FIG.  4    shows a side sectional view through the window and the camera system in yet another embodiment; 
         FIG.  5    shows a side sectional view through the window and the camera system in yet another embodiment; 
         FIG.  6    shows a side sectional view through the window and the camera system in yet another embodiment; 
         FIG.  7    shows a side sectional view through the window and the camera system in yet another embodiment; 
         FIG.  8    shows a side sectional view through the window and the camera system in yet another embodiment; and 
         FIG.  9    shows a side sectional view through the window and the camera system in yet another embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. 
     In accordance with an exemplary embodiment,  FIG.  1    shows a vehicle  100 . The vehicle  100  includes a window  102  having a camera system  104  embedded therein. The window  102  can be any window of the vehicle  100 , including a windshield, a side window, rear window, etc. In addition, the window  102  can be a glass surface of an object, such as a mirror, etc. For illustrative purposes, the window  102  as discussed herein is a windshield that separates an outer region  106  of the vehicle  100  from an interior region  108 . As disclosed herein, a camera system  104  is embedded within the windshield. The camera system  104  is coupled to a processor  110 , which receives data or a signal from the camera system and records an image based on the data or signal. The processor  110  can use the image for various purposes, such as vehicle monitoring, vehicle navigation, etc. For ease of illustration, a coordinate system  112  is shown corresponding to a location of the camera system  104  within the window  102 . The z-axis of the coordinate system  112  is directed perpendicularly out of the window  102  and into the outer region  106 . The x-axis and y-axis lie within, or substantially within, the plane of the window  102 . 
       FIG.  2    shows a side sectional view  200  through a window  102  of the vehicle  100  and a camera system  104  embedded therein, in an embodiment. The z-axis  205  of the coordinate system  112  is shown for ease of illustration. The window  102  includes a first glass layer (inner glass layer  202 ) and a second glass layer (outer glass layer  204 ). An optical bonding material is disposed within a gap  207  between the inner glass layer  202  and the outer glass layer  204 . The optical bonding material can be an adhesive material. The optical bonding material is optically transparent or optically clear. 
     The camera system  104  includes an image sensor  208  and a lens  210 . The image sensor  208  and the lens  210  are embedded within the optical bonding layer  206   b . Light entering the window  102  via the outer glass layer  204  passes through the lens  210  and is focused on the image sensor  208 . The image sensor  208  can be a photodetector array, charged coupled device or any other suitable imaging device. The image sensor  208  is disposed on a backplane film  212  and is electrically coupled to the backplane film. The backplane film  212  includes conductive wires therein through which electrical signals can be passed from the image sensor  208  to other devices, such as the processor  110 . The conductive wires can also be used to provide power to the image sensor  208 . The backplane film  212  can be a transparent substrate or a black printed substrate. As shown in  FIG.  2    the optical bonding material can be used to form a plurality of bonding layers, with layers on both sides of the backplane film  212 . In the embodiment of  FIG.  2   , the optical bonding material forms a bottom bonding layer  206   a  and the optical bonding layer  206   b . The bottom bonding layer  206   a  is disposed between the inner glass layer  202  and the backplane film  212 . The optical bonding layer  206   b  is disposed between the backplane film  212  and the outer glass layer  204 . 
     The lens  210  is located in front of the image sensor  208  and is separated from the image sensor  208  by a separation distance  214 . In various embodiments, the separation distance  214  is a focal length of the lens  210 . Therefore, light passing through the lens  210  via the outer glass layer  204  is focused by the lens onto the image sensor  208 . The lens  210  also defines a field of view for the image sensor  208 . In various embodiments, the lens is a micro-lens. The lens  210  is embedded in the optical bonding layer  206   b  at a separation distance  214  from the image sensor  208  and the optical bonding layer  206   b  maintains the separation distance  214 . The optical properties of the optical bonding layer  206   b  can be selected to facilitate optical efficiency of the lens  210  or transmission of light from the lens  210  to the image sensor  208 . 
       FIG.  3    shows a side sectional view  300  through the window  102  and the camera system  104  in another embodiment. The camera system  104  includes an image sensor array  302  including a plurality of image sensors  208  and a lens array  304  including a plurality of lenses  210 . Each image sensor  208  of the image sensor array  302  is disposed on, and electrically coupled to, the backplane film  212 . Each lens  210  of the lens array  304  is located in front of a corresponding image sensor  208  of the image sensor array  302  and separated from its corresponding image sensor  208  by a separation distance  214  (e.g., the focal length of the lens). A portion of the optical bonding layer  206   b  maintains the separation distance  214  between each of lens  210  and its corresponding image sensor  208 . In the embodiment of  FIG.  3   , each lens  210  is a separate element that is not connected to its adjacent or neighboring lens. 
       FIG.  4    shows a side sectional view  400  through the window  102  and the camera system  104  in yet another embodiment. A micro-lens film  402  is disposed in the gap  207  between the inner glass layer  202  and the outer glass layer  204 . The micro-lens film  402  can be a planar sheet, or substantially planar, sheet of material. The lenses  210  of the lens array  304  are formed as a part of the micro-lens film  402 . The micro-lens film  402  can be placed between the optical bonding layer  206   b  and a top bonding layer  206   c . The top bonding layer  206   c  is made of the optical bonding material. The optical bonding layer  206   b  has a thickness that maintains the lens array  304  at a separation distance  214  from the image sensor array  302 , thereby facilitating the placement of each lens  210  at the separation distance  214  (i.e., the focal length) from its corresponding image sensor  208 . This reduces the labor required to place each lens individually with respect to its corresponding sensor, as is performed when manufacturing the embodiment of  FIG.  3   . 
       FIG.  5    shows a side sectional view  500  through the window  102  and the camera system  104  in yet another embodiment. A hollow chamber  502  is formed in the optical bonding layer  206   b . The image sensors  208  and the lenses  210  are disposed in the hollow chamber  502 . A structure  504  is disposed within the hollow chamber  502  to hold the lenses  210  in the hollow chamber  502  at the separation distance  214  from their corresponding image sensors  208 . The lenses  210  can be separate elements or part of a micro-lens film  402 . 
       FIG.  6    shows a side sectional view  600  through the window  102  and the camera system  104  in yet another embodiment. The optical bonding layer  206   b  includes the hollow chamber  502 , and the image sensors  208  are disposed in the hollow chamber  502 . Micro-lens film  402  includes the lenses  210 . The outer edges  602  of the micro-lens film  402  are sandwiched between the optical bonding layer  206   b  and a top bonding layer  206   c , allowing the micro-lens film  402  to extend along a roof or top surface of the hollow chamber  502 , thereby suspending the lenses  210  above their respective image sensors  208  at the separation distance  214 . The top bonding layer  206   c  is disposed between the micro-lens film  402  and the outer glass layer  204 . 
       FIG.  7    shows a side sectional view  700  through the window  102  and the camera system  104  in yet another embodiment. The embodiment of  FIG.  7    includes the hollow chamber  502 , micro-lens film  402  and the top bonding layer  206   c  of  FIG.  6   . Instead of the array of image sensors  208  in  FIG.  6   ,  FIG.  7    includes an array of infrared (IR) micro light emitting diodes (IR micro-LEDs  702 ) and IR micro sensors  704 . The IR micro-LEDs  702  and IR micro sensors  704  can form an alternating pattern. The micro-lens film  402  includes a first set of lenses  706  for the IR micro-LEDs  702  and a second set of lenses  708  for the IR micro sensors  704 . The micro-lens film  402  can be arranged so that the first set of lenses  706  lies in front of the IR micro-LEDs  702  and the second set of lenses  708  lies in front of the IR micro sensors  704 , with each lens maintained at the separation distance  214  from their respective LEDs. The first set of lenses  706  disperses light from their respective IR micro-LEDs  702  into an environment, and the second set of lenses  708  focuses incoming light from the environment onto their respective IR micro sensors  704 . 
     An interlayer band pass filter  710  and a cap bonding layer  206   d  are disposed between the top bonding layer  206   c  and the outer glass layer  204 . The interlayer band pass filter  710  is disposed between the top bonding layer  206   c  and the cap bonding layer  206   d . The interlayer band pass filter  710  is opaque in the visible light region of the electromagnetic spectrum and therefore hides or disguises the presence of the lenses and sensors. The interlayer band pass filter  710  can be transmissive in the infrared portion of the electromagnetic spectrum. 
       FIG.  8    shows a side sectional view  800  through the window  102  and the camera system  104  in yet another embodiment. In contrast to  FIG.  7   , the cap bonding layer  206   d  is absent from  FIG.  8    and the interlayer band pass filter  710  is therefore in direct contact with the outer glass layer  204 . 
       FIGS.  2 ,  3  and  5    show lenses with concave optical surfaces facing away from their respective image, sensors while  FIGS.  4  and  6 - 8    shows lenses with concave optical surfaces facing toward their respective image sensors. It is to be noted, however, that the direction of orientation of the lenses or their concave optical surfaces is not meant as a limitation. In addition, the optical surfaces can be either concave or convex depending on manufacturability or applications. 
       FIG.  9    shows a side sectional view  900  through the window  102  and the camera system  104  in yet another embodiment. The camera system  104  includes the image sensor  208  and the lens  210  arranged in an opposite orientation from the arrangement shown in  FIG.  2   . The image sensor  208  and the lens  210  are disposed within the bottom bonding layer  206   a  between the inner glass layer  202  and the backplane film  212 . The image sensor  208  is coupled to the backplane film  212  and the lens  210  is proximate the inner glass layer  202 . The bottom bonding layer  206   a  maintains the separation distance  214  between the image sensor  208  and the lens  210  at a focal length of the lens  210 . This arrangement of image sensor  208  and lens  210  allows for imaging of the cabin or interior region  108 . 
     While the above disclosure has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from its scope. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiments disclosed, but will include all embodiments falling within the scope thereof.