# Patent

## Title
Vehicle vision system having adjustable displayed field of view

## Abstract

A vision system for a vehicle is provided including a camera for capturing images within a field of view; a display device movably mounted relative to the vehicle for displaying a portion of the field of view of the camera; a movement sensor for sensing movement of the display device; and a processing circuit in communication with the movement sensor, the display device, and the camera for selecting the portion of the field of view to be displayed on the display device in response to movement of the display device as sensed by the movement sensor.

## Background
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to and the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 62/097,315, filed on Dec. 29, 2014, entitled “VEHICLE VISION SYSTEM HAVING ADJUSTABLE DISPLAYED FIELD OF VIEW,” the entire disclosure of which is hereby incorporated herein by reference.


FIELD OF THE INVENTION
The present invention generally relates to a vehicle vision system and, more particularly, a vehicle vision system where a display is movable relative to the vehicle.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, a vehicle display system is provided for displaying images captured by a camera associated with a vehicle, wherein the camera has a field of view. The display system comprises a rearview assembly and a processing circuit. The rearview assembly comprises a mounting structure configured for mounting to the vehicle; a movable head pivotably attached to the mounting structure; a display device positioned within the movable head for displaying a portion of the field of view of the camera; and a movement sensor for sensing movement of the movable head. The processing circuit is in communication with the movement sensor and the display device for selecting the portion of the field of view to be displayed on the display device in response to movement of the movable head as sensed by the movement sensor.
According to another aspect of the present invention, a vision system for a vehicle is provided comprising a camera for capturing images within a field of view; a display device movably mounted relative to the vehicle for displaying a portion of the field of view of the camera; a movement sensor for sensing movement of the display device; and a processing circuit in communication with the movement sensor, the display device, and the camera for selecting the portion of the field of view to be displayed on the display device in response to movement of the display device as sensed by the movement sensor.
According to another aspect of the present invention, a vehicle display system is provided for displaying images captured by a camera associated with a vehicle, wherein the camera has a field of view. The display system comprises a user input; a display device for displaying a portion of the field of view of the camera; and a processing circuit in communication with the user input and the display device for selecting the portion of the field of view to be displayed on the display device in response to movement of the user input.
These and other features, advantages, and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings.



BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is an electrical diagram in block form of a vehicle vision system;
FIG. 2A is an electrical diagram in block form of a more detailed vehicle vision system according to one implementation;
FIG. 2B is an electrical diagram in block form of a more detailed vehicle vision system according to an alternative implementation;
FIG. 3A is a front elevational view of a rearview assembly including a reverse camera display;
FIG. 3B is a front elevational view of a rearview assembly including a full display mirror;
FIG. 4A is an illustration of a mirror image of a camera field of view with a display field of view superimposed in a first position;
FIG. 4B is an illustration of a mirror image of a camera field of view with a display field of view superimposed in a second position;
FIG. 4C is an illustration of a mirror image of a camera field of view with a display field of view superimposed in a third position;
FIG. 5 is an exploded view of a rearview assembly;
FIG. 6A is a side elevational view of a movement sensor used in the rearview assembly of FIG. 5;
FIG. 6B is another side elevational view of the movement sensor shown in FIG. 6A; and
FIG. 6C is a perspective view of the movement sensor shown in FIGS. 6A and 6B.



DETAILED DESCRIPTION OF THE EMBODIMENTS
The present illustrated embodiments reside primarily in combinations of method steps and apparatus components related to a vehicle vision system, particularly one having a display device in a vehicle rearview assembly. Accordingly, the apparatus components and method steps have been represented, where appropriate, by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Further, like numerals in the description and drawings represent like elements.
For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in FIGS. 3A and 3B. Unless stated otherwise, the term “front” shall refer to the surface of the element closer to an intended viewer of the rearview assembly, and the term “rear” shall refer to the surface of the element further from the intended viewer of the rearview assembly. However, it is to be understood that the invention may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.
The terms “including,” “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element preceded by “comprises . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.
The embodiments described herein relate to a vehicle vision system. Vehicle vision systems are known in which a camera is mounted to a vehicle for capturing images for display on a display device positioned in the vehicle for viewing by the driver of the vehicle. In some of these vehicle vision systems, the display is located in the inside rearview mirror assembly. Such displays may be smaller in size than the mirror element and positioned behind the mirror element such that images generated by the display may be seen through the mirror element when the display is activated. Further, the mirror element may be transflective so as to hide the display when not activated. In some such vision systems, the function of the display is that of a reverse camera display (RCD) in which the display is activated when the vehicle is placed in reverse and displays images from a rearward facing camera for as long as the vehicle remains in reverse or for a predetermined time thereafter. These RCDs typically have a viewing area less than that of the mirror element. Examples of RCDs are described in U.S. Pat. No. 8,339,526 and United States Patent Application Publication No. US 2009/0096937 A1, the entire disclosures of which are incorporated by reference.
Some vehicle vision systems are designed to have a display that has an area substantially corresponding to the mirror element. In these systems the display is configured to display images from a rearward-facing camera whenever activated by the driver. Examples of these “full display mirrors” (FDMs) are described in U.S. Pat. No. 8,339,526; and United States Patent Application Publication Nos. US 2009/0096937 A1, US 2015/0266427 A1, and US 2015/0277203 A1, the entire disclosures of which are incorporated by reference.
In vehicle vision systems it may be desired from an acceptance standpoint to have the displayed images simulate the images one would see from reflections from a conventional mirror. On the other hand, it may be desirable from a safety standpoint to display a greater field of view than would be seen with a conventional mirror. This latter objective is possible insofar as the camera is typically mounted outside the vehicle so as to not have its field of view obscured by objects in the vehicle or the rear pillars of the vehicle that are adjacent the rear window. To accommodate these seemingly incompatible goals, the embodiments described herein allow the driver to select the field of view to be displayed. As described below, this may be accomplished by changing the field of view as the driver moves the mirror housing or as the driver manipulates a user input. The change in field of view may be performed in a manner that simulates the change in field of view that the driver would otherwise experience when moving a conventional mirror housing.
An example of a vehicle vision system 10 is shown in FIG. 1. As shown, vehicle vision system 10 includes a camera system 20 and a display system 30. The camera system 20 and display system 30 are shown as two separate systems insofar as they may be located in separate locations of the vehicle and disposed in different vehicle components or accessories. For example, as described further below, display system 30 may be disposed in a rearview assembly 100 (FIGS. 3A, 3B, and 5) whereas camera system 20 may be disposed at the rear and/or sides of the vehicle.
FIGS. 2A and 2B show two different implementations of the embodiments described herein. In the implementation shown in FIG. 2A, camera system 20 includes a camera 25 that captures images of a field of view. Display system 30 includes a movement sensor 32, display drivers 34, a display device 35, and a processing circuit 40. Display device 35 is configured to display a portion of the field of view captured by the camera. Display system 30 may be wholly or partially disposed in the vehicle such that display device 35 is movably mounted relative to the vehicle. Movement sensor 32 is provided for sensing movement of display device 35. As described in detail below, processing circuit 40 is in communication with movement sensor 32, display device 35 (via display drivers 34), and camera 25 for selecting the portion of the field of view to be displayed on display device 35 in response to movement of display device 35 as sensed by movement sensor 32.
The implementation shown in FIG. 2B differs from the implementation shown in FIG. 2A in that processing circuit 40 is part of camera system 20 and may therefore be located in the same vehicle component or accessory as camera 25. In this implementation, processing circuit 40 receives output from movement sensor 32 via a vehicle bus or discrete connection, and selects the portion of the field of view to be displayed on display device 35 in response to movement of display device 35 as sensed by movement sensor 32. An optional processor 42 may be provided in display system 30 to facilitate communication with processing circuit 40 and to perform any other processing functions for the component in which display system 30 is disposed. For example, if provided in a rearview assembly, processor 42 may be configured to compute a heading from compass sensors, control dimming of an electro-optic mirror element, or perform any other function commonly executed by a processor in a mirror housing. Although shown as being part of either camera system 20 or display system 30, processing circuit 40 may be located separate from either system.
As mentioned above, display system 30 may be mounted in a rearview assembly 100. As shown in FIG. 3A, rearview assembly 100 may include display device 35 disposed in a mirror housing 120 and positioned and sized so as to function as an RCD in which the display area is smaller than the total viewable area of the rearview assembly. Rearview assembly 100 may include a mirror element 140 disposed in mirror housing 120 in front of or behind display device 35 such that rearview assembly 100 functions as a rearview mirror assembly. Mirror element 140 may include a transmissive window 141 (FIG. 5) in front of display device 35 such that displayed images from display device 35 may be seen through mirror element 140. Mirror element 140 may be transflective over its entire viewable area or within window 141 such that display device 35 is hidden when not activated.
As shown in FIG. 3B, rearview assembly 100 may include display device 35 disposed in mirror housing 120 and positioned and sized so as to function as an FDM in which the display area is substantially the same size as the total viewable area of the rearview assembly. Mirror element 140 may be transflective over its entire viewable area such that display device 35 is hidden when not activated. For both RCD and FDM versions of rearview assembly 100, a user-actuated switch 200 may be provided for activating or deactivating display device 35 in the manner disclosed in United States Patent Application Publication Nos. US 2009/0096937 A1, US 2015/0266427 A1 and US 2015/0277203 A1, the entire disclosures of which are incorporated herein by reference. To the extent that user activation of switch 200 may cause movement of display device 35, any movement sensed by movement sensor 32 may be overridden if actuation of switch 200 is detected since such actuation would otherwise deactivate display device 35 or activate it from a previously deactivated state.
FIG. 4A shows an example of a mirror-imaged (or reversed) field of view 80 of camera 25 with a portion 82a of field of view 80 shown in dashed lines. The portion 82a is intended to show the portion of the field of view that is displayed on display device 35. As illustrated, the camera field of view 80 is larger than the portion 82a to be displayed. As explained above, it may be desirable to simulate a rearview mirror, particularly when the display is configured as an FDM. Because a rearward-facing camera captures images directly to the rear as opposed to a mirror image as would be seen by a driver, it may be desirable to reverse the images captured by the camera before displaying on display 35 so that the displayed images appear as they would when reflected from a mirror. Further, in a rearview mirror assembly with just a mirror element, movement of the mirror housing 120 changes the field of view as seen by the driver. However, in conventional FDMs, movement of the mirror housing does not cause the displayed field of view to change as the camera remains stationary relative to the vehicle. Accordingly, processing circuit 40 is provided and configured to select the portion 82a of the camera field of view 80 that is to be displayed on display device 35 in response to any movement sensed by movement sensor 32. Thus, for example, in response to horizontal rotation of mirror housing 120, processing circuit 40 shifts the displayed field of view by selecting a portion 82b (FIG. 4B) of field of view 80 that is horizontally shifted from the prior displayed portion 82a (FIG. 4A). The portion displayed may be gradually and continuously shifted to mimic the change in field of view if moving a mirror element in the same manner. Similarly, in response to vertical tilting of mirror housing 120, processing circuit 40 shifts the displayed field of view by selecting a portion 82c (FIG. 4C) of field of view 80 that is vertically shifted from the prior portion 82a (FIG. 4A).
Although a single field of view of a single camera is described above, the field of view 80 may be a composite field of view from multiple cameras with the images merged together to form one seamless panoramic image. Thus, movement of mirror housing 120 may enable or disable different cameras or otherwise select from the fields of view of particular cameras such that movement of mirror housing 120 causes the field of view of display device 35 to effectively pan across the much larger panoramic field of view. It should be noted that a user-selectable mechanism may also be provided to allow a driver to zoom in or out the displayed field of view.
It should further be appreciated that the displayed field of view may be varied through movement of the mirror housing 120 by causing the camera 25 to pan and tilt if capable of doing so.
FIG. 5 shows an exploded view of an exemplary rearview assembly 100. As shown, rearview assembly 100 includes mirror housing 120, a mounting structure 445 for pivotally mounting mirror housing 120 to the vehicle such that mirror housing 120 may be both vertically and horizontally tilted relative to the vehicle. In FIG. 5, reference numeral 240 represents a windshield of the vehicle to which a mounting foot 450 of mounting structure 445 may be secured. It will be understood by those skilled in the art that mounting structure 445 may alternatively be secured to the roof structure of the vehicle above the windshield. In some applications, a single ball mount is preferable so that measurements of the rotational position on the single ball accurately indicate the position of the mirror in the vehicle. Mounting structure 445 further includes a mounting ball 501 and a mounting stem 502 extending between ball 501 and mounting foot 450.
Mirror element 140 is mounted in mirror housing 120. An optional compass sensor 320 may be disposed in mirror housing 120 and coupled to processing circuit 40 (or processor 42). Compass sensor 320 generally includes an X-axis magnetic field sensor 440, a Y-axis magnetic field sensor 460, and an optional Z-axis sensor (not shown). Sensors 440 and 460, as well as processing circuit 40, may be mounted on a printed circuit board 160.
Display device 35 is fixedly mounted in mirror housing 120 and may either be mounted on a front surface of printed circuit board 160 or to the rear surface of the mirror element so as to project light through a window portion 141 provided in the reflective surface of mirror element 140. Display device 35 may alternatively be mounted on a daughter circuit board (not shown). Further, display device 35 may be mounted in front of mirror element 140.
Mirror element 140 may be an electro-optic mirror. The sensors and circuitry for automatically varying the transmittance and hence reflectivity of electro-optic mirror element 140 may also be mounted on printed circuit board 160. Such circuitry may be coupled to mirror 140 via wires 142 in any conventional manner.
As mentioned above, rearview assembly 100 further includes movement sensor 32 for detecting when mirror housing 120 and hence display device 35 have been moved from a prior position. Movement sensor 32 then generates and transmits a movement detection signal to processing circuit 40 such that processing circuit 40 may take into account the fact that the mirror housing 120 and hence display device 35 have been tilted when selecting a portion of the camera field of view to display.
Movement sensor 32 may have any configuration capable of sensing movement of mirror housing 120. Examples of movement sensors for sensing movement of a mirror housing are disclosed in U.S. Pat. No. 6,140,933, the entire disclosure of which is incorporated by reference. An example of one such movement sensor disclosed in U.S. Pat. No. 6,140,933 is described below with reference to FIGS. 6A-6C.
In FIGS. 6A and 6B, a pivot ball 501 for a single ball mirror mount 445 (FIG. 5), a portion of circuit board 160, and the components used to measure the position of the mirror housing 120 on the mount are shown. Ball 501 is attached to the automobile by stem 502 via a mounting bracket 450 (FIG. 5). The assembly is viewed from the side. A target 501a is provided on the pivot ball 501. Two of four LEDs, 506 and 507, are shown in FIGS. 6A and 6B, and are respectively disposed below and above a sensor 516 and are used for sensing vertical movement of mirror housing 120. These LEDs may be momentarily lighted one at a time, and the light individually reflected off of target 501a by each of the LEDs is measured by sensor 516, which may be a photodiode. As shown in FIG. 6C, movement sensor 32 may further include LEDs 508 and 509 laterally disposed on either side of sensor 516 for sensing horizontal movement of mirror housing 120.
Target 501a may be a white spot provided on a black or dark ball 501. Conversely, the target could be a black spot on a white or highly reflective ball 501. Basically, the target can be any color that contrasts with the mirror ball, where “color” is defined as the reflectance at the light spectrum being used. In general, it is the contrast difference between the target region 501a and the surrounding area that is being measured. The target can be painted on ball 501, a separate plastic member, an adhesive sticker, or even a variation in surface texture of ball 501. Additionally, a void can be molded into ball 501 that appears as a black target on a light background. Further, ball 501 may be made of metal and have a portion mirrored to serve as target 501a. 
Movement sensor 32 may also be provided by way of a magnetic field sensor such as a three-axis compass sensor provided in the mirror housing 120 as disclosed in U.S. Pat. No. 6,928,366, the entire disclosure of which is incorporated by reference. It may also be desirable to provide capacitive touch sensors at locations on the top and bottom of mirror housing 120 where a driver is likely to grasp mirror housing 120 for purposes of moving it. Such capacitive touch sensors would thus provide additional information for processing circuit 40 to ascertain that the mirror housing 120 has been moved by the driver.
Although the embodiments are described above as being adapted for use with an interior rearview assembly, the display device may likewise be positioned in an exterior rearview assembly. In this case, because most vehicles do not require a driver to physically move an outside mirror element, movement sensor 32 (FIG. 1) may be part of a user input 31 so as to sense movement of a user input mechanism 33. User input mechanism 33 may take the form of any conventional mechanism used to move outside mirrors such as a joystick or multiple switches for moving the mirror element right, left, up, and down. Movement sensor 32 may thus be configured differently depending upon the form of user input mechanism 33 that is used and may be constructed in the same manner as for conventional mirror position switches. The main difference between this arrangement and conventional arrangements is that processing circuit 40 responds to user input 31 by selecting the portion of the field of view to be displayed on display device 35. This may avoid the need for a motor pack that would otherwise be required to physically move a conventional exterior mirror element.
Although the use of such input 31 has been described with respect to exterior mirror assemblies, user input 31 may be provided to adjust the field of view shown on display device 35 when positioned in an interior location such as the interior rearview assembly 100 described above. Moreover, the same user input 31 may be used for interior rearview assembly 100 and both exterior assemblies by providing a selector switch so as to select the display on which the field of view is to be adjusted.
The above description is considered that of the preferred embodiments only. Modifications of the invention will occur to those skilled in the art and to those who make or use the invention. Therefore, it is understood that the embodiments shown in the drawings and described above are merely for illustrative purposes and not intended to limit the scope of the invention, which is defined by the claims as interpreted according to the principles of patent law, including the doctrine of equivalents.

## Claims

1. A vehicle display system for displaying images captured by a camera associated with a vehicle, wherein the camera has a field of view and outputs image data representing a scene within the entire field of view of the camera, the display system comprising:
a rearview assembly comprising:
a mounting structure configured for mounting to the vehicle;
a movable head pivotably attached to said mounting structure;
a display device positioned within said movable head for displaying a portion of the field of view of the camera;
a movement sensor for sensing movement of said movable head;
a mirror element disposed in said moveable head, wherein said display device is positioned behind said mirror element; and
a switch disposed on said moveable head for selectively activating and deactivating said display device; and

a processing circuit in communication with said switch, said movement sensor, and said display device for receiving the image data from the camera and selecting the portion of the field of view to be displayed on said display device in response to movement of said movable head as sensed by said movement sensor, wherein the portion of the field of view selected by the processing circuit for display on the display device is smaller than the field of view of the camera represented by the image data, and wherein any movement of said movable head that is sensed is overridden when said switch has been actuated to prevent inadvertent adjustment of the portion of the field of view to be displayed on said display device caused by movement of said movable head during actuation of said switch.

2. The vehicle display system of claim 1, wherein said processing circuit is disposed in said movable head.

3. The vehicle display system of claim 1, wherein said processing circuit shifts the portion of the field of view horizontally when said movable head is moved horizontally.

4. The vehicle display system of claim 1, wherein said processing circuit shifts the portion of the field of view vertically when said movable head is moved vertically.

5. The vehicle display system of claim 1, wherein said mounting structure includes a ball for mounting to said moveable head, said movement sensor comprises:
a target provided on an area of said ball of said mounting structure, said target having a different visual characteristic than other surrounding areas of said ball;
a light source for projecting light onto said ball; and
a photodetector for detecting the level of light reflected from said ball,
wherein said processing circuit is coupled to said photodetector for sensing movement of said moveable head when the level of reflected light detected by said photodetector changes.

6. The vehicle display system of claim 1, wherein said mirror element is transflective such that displayed images from said display device are visible through the mirror element when the display is activated and the display device is hidden when deactivated.

7. The vehicle display system of claim 1, wherein said processing circuit is mounted in said moveable head.

8. A vision system for a vehicle comprising:
a camera for capturing images within a field of view and outputting image data representing a scene within the entire field of view of the camera;
a display device movably mounted relative to the vehicle for displaying a portion of the field of view of said camera;
a movement sensor for sensing movement of said display device; and
a switch disposed near said display device for selectively activating and deactivating said display device; and
a processing circuit in communication with said switch, said movement sensor, said display device, and said camera for receiving the image data and selecting the portion of the field of view to be displayed on said display device in response to movement of said display device as sensed by said movement sensor, wherein the portion of the field of view selected by the processing circuit for display on the display device is smaller than the field of view of the camera represented by the image data, and wherein any movement of said display device that is sensed is overridden when said switch has been actuated to prevent inadvertent adjustment of the portion of the field of view to be displayed on said display device caused by movement of said display device during actuation of said switch.

9. The vision system of claim 8, wherein said display device is disposed in a mirror housing of a rearview mirror assembly, and wherein said movement sensor senses movement of said display device by sensing movement of said mirror housing.

10. The vision system of claim 9, wherein said processing circuit is disposed in said mirror housing.

11. The vision system of claim 8, wherein said processing circuit shifts the portion of the field of view horizontally when said display device is moved horizontally.

12. The vision system of claim 8, wherein said processing circuit shifts the portion of the field of view vertically when said display device is moved vertically.

13. The vision system of claim 9, wherein said rearview mirror assembly comprises a mounting structure configured for mounting to the vehicle, said mounting structure includes a ball for mounting to said mirror housing, wherein said movement sensor comprises:
a target provided on an area of said ball of said mounting structure, said target having a different visual characteristic than other surrounding areas of said ball;
a light source for projecting light onto said ball; and
a photodetector for detecting the level of light reflected from said ball,
wherein said processing circuit is coupled to said photodetector for sensing movement of said moveable housing when the level of reflected light detected by said photodetector changes.

14. The vision system of claim 9 and further comprising a mirror element disposed in said mirror housing, wherein said display device is positioned adjacent said mirror element.

15. The vision system of claim 8, wherein said camera is mounted in a camera module disposed at a rear of the vehicle.

16. The vision system of claim 15, wherein said processing circuit is disposed in the camera module.

17. The vision system of any one of claim 9, wherein said movement sensor comprises a magnetic field sensor provided in said mirror housing.

18. The vision system of claim 9, wherein said movement sensor comprises capacitive touch sensors at locations on a top and a bottom of said mirror housing.

19. A vehicle display system for displaying images captured by a camera associated with a vehicle, wherein the camera has a field of view and outputs image data representing a scene within the entire field of view of the camera, the display system comprising:
a user input;
a display device for displaying a portion of the field of view of said camera;
a switch for selectively activating and deactivating said display device; and
a processing circuit in communication with said switch, said user input and said display device for receiving the image data from the camera and selecting the portion of the field of view to be displayed on said display device in response to said user input, wherein the portion of the field of view selected by the processing circuit for display on the display device is smaller than the field of view of the camera represented by the image data, and wherein any user input that is received is overridden when said switch has been actuated to prevent inadvertent adjustment of the portion of the field of view to be displayed on said display device caused by user input received as a result of actuation of said switch.

20. The vehicle display system of claim 19, wherein said processing circuit shifts the portion of the field of view both horizontally and vertically in response to in response to said user input.