Patent Abstract:
A vehicular rearview mirror system includes an interior rearview mirror assembly having an interior electrochromic reflective element. The interior rearview mirror assembly includes a control that has circuitry operable to provide a drive signal to the reflective element to vary the reflectance level of the interior electrochromic reflective element. The control includes a bus interface that interfaces with a vehicle bus of the equipped vehicle. The interior rearview mirror system includes a forward-facing camera. The control may control at least one of (a) operation of a video display, (b) operation of the forward-facing camera and (c) operation of a headlight control for controlling a headlight of the equipped vehicle. The interior rearview mirror assembly may include a video display operable to display video information for viewing by a driver of the vehicle.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No, 12/693,720, filed Jan, 6, 2010, now U.S. Pat. No. 8,044,777, which is a continuation of U.S. patent application Ser. No. 11/764,559, filed Jun. 18, 2007, now U.S. Pat. No. 7,679,488, which is a continuation of U.S. patent application Ser. No. 11/288,649, filed Nov. 29, 2005, now U.S. Pat. No. 7,233,230, which is a continuation of U.S. patent application Ser. No, 10/694,595, filed Oct. 27, 2003, now U.S. Pat. No. 6,970,073, which is a continuation of U.S. patent application Ser. No, 10/134,716, filed on Apr. 29, 2002, now U.S. Pat. No. 6,639,519, which is a continuation of U.S. patent application Ser. No. 09/820,013, filed on Mar. 28, 2001, now U.S. Pat. No. 6,396,408, which claims priority from U.S. provisional patent application Ser. No. 60/196,577, filed on Mar. 31, 2000, the disclosures of which are hereby incorporated herein by reference in their entireties. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates generally to vehicle rearview mirror systems and, more particularly, to digital electrochromic rearview mirror systems. 
     Digital electrochromic mirror systems are described in commonly assigned U.S. Pat. No. 6,089,721 entitled DIGITAL ELECTROCHROMIC MIRROR SYSTEM and U.S. Pat. No. 6,056,410 entitled DIGITAL ELECTROCHROMIC MIRROR SYSTEM, the disclosures of which are hereby incorporated herein by reference. Such systems are capable of controlling the reflectance level of an electrochromic element from the output of a microcomputer. 
     Various forms of vehicle communication systems have been developed including wired networks, or busses, operating one of several known protocols. These include a LIN (Local Interconnect Network), a LAN (Local Area Network), a CAN (Car or Controlled Area Network), and the like. An advantage of such vehicle networks is that the wire harness to the mirror can be minimized to as few as three wires or so, yet provide a variety of functions. Wireless communication networks utilizing radio frequency and/or infrared communication for vehicles have also been proposed, such as those utilizing the BLUETOOTH protocol. Such wireless communication and the BLUETOOTH protocol are described in more detail in commonly assigned U.S. patent application Ser. No. 09/793,002, filed Feb. 26, 2001, entitled VIDEO MIRROR SYSTEMS INCORPORATING AN ACCESSORY MODULE, now U.S. Pat. No. 6,690,268, the disclosure of which is hereby incorporated herein by reference. 
     Trainable garage door openers, such as a universal garage door opener available from Johnson Controls/Prince Corporation, Holland, Mich. under the trade name HOMELINK™, include a transmitter for a universal home access system, which replaces the switch in a household garage door opener that opens/closes the garage door. A garage door opener communicating with a smart switch that is programmable to a household specific code that is of the rolling code type, such as is available from TRW Automotive, Farmington Hills, Mich. under the trade name KWIKLINK™, is known to be mounted within vehicles. As described in commonly assigned U.S. Pat. No. 6,172,613, the disclosure of which is hereby incorporated herein by reference, the universal garage door opener HOMELINK™ unit or the universal home access KWIKLINK™ unit may be mounted at, within, or on an interior rearview mirror assembly. The KWIKLINK™ system is a low-current device that can, optionally, be operated off of a battery source, such as a long-life lithium battery. It is also compact and lightweight as executed on a single-or double-sided printed circuit board. 
     SUMMARY OF THE INVENTION 
     The present invention provides a new and unique combination of a digital electrochromic mirror system, a vehicle accessory and a vehicle network, and, more particularly, a combination of a digital electrochromic mirror system, a garage door opener and a vehicle network. According to an aspect of the invention, a vehicular rearview mirror system includes a digital electrochromic mirror system having a digital drive circuit and an electrochromic reflective element. The reflective element assumes a partial reflectance level in response to a drive signal. The drive circuit provides a drive signal to the reflectance element. The mirror system further includes a garage door opener including a transmitter and a logic circuit. The logic circuit supplies signals to the transmitter for transmitting garage door opening signals. The mirror system further includes a microcontroller which defines, at least in part, the digital drive circuit and the logic circuit. In this manner, the digital electrochromic mirror system has components in common with the garage door opener. According to this aspect of the invention, the microcontroller communicates over a vehicle network with at least a module performing at least one other vehicle function. The vehicle network may have at least wired network connections and may further have wireless connections. The vehicle network may have a protocol selected from the group consisting of a LIN, a CAN, or a LAN. 
     According to this aspect of the invention, the digital drive circuit and the logic circuit may be mounted on a common circuit board. Power to the digital drive circuit and logic circuit may be supplied from a battery, preferably a rechargeable battery, that is separate from the vehicle ignition. The battery may be charged from a solar power system. 
     According to another aspect of the invention, a vehicle rearview mirror system includes an interior rearview mirror system made up of an electrochromic reflective element, a housing for the electrochromic reflective element and a circuit board in the housing. The electrochromic reflective element assumes a partial reflectance level in response to a drive signal. A digital electrochromic drive circuit is provided on the circuit board and supplies a drive signal to the reflective element. The mirror system further includes a garage door opener. The garage door opener includes a transmitter and a logic circuit, at least one of which (and preferably, both) is on the circuit board, and share Components with, the electrochromic drive circuit. The logic circuit supplies signals to the transmitter for transmitting garage door opening signals. The garage door opener may, optionally and preferably, also serve as a receiver or a transceiver for a tire pressure status monitoring/display system, such as disclosed in commonly assigned U.S. patent application Ser. No. 09/513,941, filed Feb. 28, 2000, entitled TIRE INFLATION ASSISTANCE MONITORING SYSTEM, now U.S. Pat. No. 6,294,989, and U.S. patent application Ser. No, 09/710,016, filed Nov. 10, 2000, entitled TIRE INFLATION ASSISTANCE MONITORING SYSTEM, now U.S. Pat. No. 6,445,287, the disclosures of which are hereby incorporated herein by reference, and thus have a dual tire pressure monitoring/display and garage door opener function. The mirror system further includes a microcontroller which defines, at least in part, the digital drive circuit and the logic circuit. The digital electrochromic mirror system has components in common with the garage door opener. The microcontroller communicates over a vehicle network with at least one module performing at least one other vehicle function. 
     These and other objects, advantages and features of this invention will become apparent upon review of the following specification in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top plan view of a vehicle having a vehicular rearview mirror system, according to the invention; 
         FIG. 2  is an electronic block diagram of a digital electrochromic mirror system, according to the invention; and 
         FIG. 3  is an electronic block diagram of a vehicular rearview mirror system, according to the invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now specifically to the drawings, and the illustrative embodiments depicted therein, a vehicular rearview mirror system  10  is illustrated with a vehicle  11  and includes an interior rearview mirror assembly  16  and one or more exterior rearview mirror assemblies, such as driver side exterior rearview mirror assembly  12  and/or passenger side exterior rearview mirror assembly  14  ( FIG. 1 ). Interior rearview mirror assembly  16  includes a digital electrochromic mirror system  18  which is preferably supplied according to the principles disclosed in commonly assigned U.S. Pat. Nos. 6,089,721 and 6,056,410, the disclosures of which are hereby incorporated herein by reference. Although the particulars of the invention are illustrated with an interior rearview mirror assembly  16 , it should be understood that the principles of the invention could be equally applied to either or both exterior rearview mirror assemblies  12 ,  14 . 
     Digital electrochromic mirror system  18  includes a microcontroller  20  and an electrochromic mirror reflective element  22 . As is disclosed in the &#39;721 and &#39;410 patents, microcontroller  20  receives inputs from light sensors  24  (preferably phototransistors or photodiodes) and supplies digital outputs  26   a ,  26   b  which control solid-state switches  28   a ,  28   b  in order to provide a drive signal at  30  thereby establishing a partial reflectance level of electrochromic reflective element  22 . Microcontroller  20  includes a microprocessor. 
     Digital electrochromic mirror system  18  further includes a bus interface  32  which interfaces with a vehicle network, or bus,  34 . Items on network  34  can be connected by wired or wireless connection. Wired connection may include wire, cables, fiber-optic cables, and the like. Wireless connection can be by infrared (IR) or radio-frequency (RF) communication, and, preferably, may be a short-range RF interconnection using the BLUETOOTH protocol. Vehicle network, or bus,  34  may utilize various buss protocols including a Local Internet Network (LIN), a Local Area Network (LAN), a Car (a/k/a Controlled) Area Network (CAN), or other vehicle network protocol. The BLUETOOTH protocol is a low-cost, low-power radio-based cable replacement or wireless link based on short-range radio-based technology. BLUETOOTH enables creation of a short-range (typically 30 feet or so, although longer and shorter ranges are possible), wireless personal area network via small radio transmitters built into various devices. For example, transmission can be on a 2.45 gigahertz band, moving data at about 721 kilobits per second, or faster. In the illustrated embodiment, network  34  is a multi-drop bus which requires three or fewer wires for communication between a plurality of other vehicle functions  36 , as illustrated in  FIG. 11   n  situations where timing and power consumption system constraints may cause network  34  wakeup time to be too slow for an automobile maker system response requirement, suitable adjustments may be made in the architecture of network  34 . The network may be configured as disclosed in commonly assigned U.S. patent application Ser. No. 09/341,450 filed Jul. 8, 1999, by Drummond et al. for a VEHICLE REARVIEW MIRROR AND A VEHICLE CONTROL SYSTEM INCORPORATING SUCH MIRROR, now U.S. Pat. No. 6,291,905, the disclosure of which is hereby incorporated herein by reference. 
     Other vehicle functions  36  include, by way of example, a seatbelt warning status  38 , which status may be displayed on a minor-based display  40 . Preferably, mirror-based display  40  may be located on, at or adjacent interior rearview mirror assembly  16 . Minor-based display  40  may be of various forms including that disclosed in commonly assigned U.S. patent application Ser. No. 09/799,414, filed on Mar. 5, 2001, by McCarthy et al., entitled COMPLETE MIRROR-BASED GLOBAL-POSITIONING SYSTEM (GPS) NAVIGATION SOLUTION, now U.S. Pat. No. 6,477,464, the disclosure of which is hereby incorporated herein by reference. Additionally, display  40  may display magnetic vehicle heading information from a magnetic sensor  42 , the information being supplied over network  34 . Additionally, reverse gear status from a reverse gear sensor  44  may be supplied over network  34  to cause digital electrochromic minor  18  to assume a high reflectance level when vehicle  11  is placed in reverse gear. Rearview mirror system  10  may additionally receive engine information  46  and/or door opener information at  48  over network  34  and activate general lighting  50  located in, at or on interior rearview mirror assembly  16 , such as when a door of vehicle  11  is opened. Status from an alarm assembly  52  may also be conveyed over network  34  and displayed by display  40 . 
     Dim ratios, or partial reflectance levels developed from light sensors  24 , can be transmitted over network  34  for use to drive exterior minors  12 ,  14 . Optionally, a dim ratio or partial reflectance level chosen for a driver-side exterior minor may be different from (and typically greater than) a dim ratio or partial reflectance level chosen for a passenger-side exterior mirror, and both may be different from a dim ratio or partial reflectance level chosen for a interior electrochromic mirror. Ambient light information, sensed by an ambient light sensor  57 , can also be transmitted over network  34  for use in dimming of instrument panel  54  or automatic headlight functions  56 . Alternatively, ambient light information can be developed by interior rearview mirror assembly  16  as disclosed in commonly assigned U.S. Pat. No. 5,715,093, the disclosure of which is hereby incorporated herein by reference. 
     The interior rearview mirror assembly includes microcontroller  20  and a printed circuit board  61 , that are common to both the digital electrochromic mirror system  18  and garage door opener function  66 . Sharing of components and circuit board space can facilitate a reduction of susceptibility to RF/EMI interference and reduce cost and avoid duplication of both the network interface hardware  32 , communication software and some processing power. The interior rearview mirror assembly may also include a video display system, such as disclosed in commonly assigned U.S. patent application Ser. No, 09/793,002, filed Feb. 26, 2001, entitled VIDEO MIRROR SYSTEM INCORPORATING AN ACCESSORY MODULE, now U.S. Pat. No. 6,690,268, the disclosure of which is hereby incorporated herein by reference. Components may be shared between the video display system, the digital electrochromic mirror system and/or the garage door opener. Additionally, microcontroller  20  may control a forward-facing camera system and headlight control which may also share components with the digital electrochromic mirror system and/or the garage door opener. Such forward-facing camera system and headlight control may be of the type disclosed in commonly assigned U.S. Pat. No. 5,796,094 entitled VEHICLE HEADLIGHT CONTROL USING IMAGING SENSOR, the disclosure of which is hereby incorporated herein by reference. An imaging sensor based rain sensor of the type disclosed in commonly assigned U.S. patent application Ser. No. 09/530,306, filed Apr. 27, 2000, entitled RAIN SENSOR WITH FOG DISCRIMINATION, now U.S. Pat. No. 6,353,392, may also be incorporated in circuit board  61  and share components with the digital electrochromic mirror system and/or the garage door opener. 
     With microcomputer  20  driving digital electrochromic mirror system  18 , and with vehicle status information available over network  34 , it is possible to have a circuit assembly  61  in or at interior rearview mirror assembly  16  that is powered by a battery  62  that is separate from the vehicle ignition storage battery. As an example, battery  62  may be of a long-life lithium type battery. Moreover, because of its relatively small size, battery  62  may be recharged by a separate dedicated solar-powered rechargeable battery source  64  of the type described in commonly assigned patent application Ser. No. 09/793,002, filed Feb. 26, 2001, entitled VIDEO MIRROR SYSTEMS INCORPORATING AN ACCESSORY MODULE, now U.S. Pat. No. 6,690,268, the disclosure of which is hereby incorporated herein by reference. By powering mirror system  10  by a separate-dedicated solar-powered rechargeable battery source, mirror system  10  can consume power from its dedicated/local battery source, and any power used up during nighttime hours can be replenished by day via solar cell/panel that is a part of battery charger  64  and is connected to the dedicated battery  62  so as to recharge/charge during daytime hours. Furthermore, microcomputer  20  can be put into various power-saving modes thereby enabling electronic assembly  61  to be used for control of a garage door opener  66 , such as a HOMELINK™ unit or the universal home access KWIKLINK™ unit. 
     Also, a mirror-mounted microphone/digital sound-processing system  68 , as disclosed in commonly assigned patent application Ser. No. 09/466,010, filed by DeLine et al., on Dec. 17, 1999, for an INTERIOR REARVIEW MIRROR SOUND-PROCESSING SYSTEM, now U.S. Pat. No. 6,420,975, the disclosure of which is hereby incorporated herein by reference, may be also powered by battery  62 . Preferably, sound-processing system  68  is incorporated in circuit assembly  61  and, most preferably, shares microcontroller  20  with garage door opener  66  and digital electrochromic mirror  18 . Communication button press information  58  can be transmitted over network  34  for various uses by other electronic control units, such as activation of a rescue system  60 , such as General Motors&#39; ONSTAR™ system, a Ford Motor Company&#39;s RESCU™ system, or the like. Use of digital signal-processing and a single mirror-mounted microphone (such as is described in U.S. patent application Ser. No. 09/396,179, filed Sep. 14, 1999, entitled INDICATOR FOR VEHICLE ACCESSORY, now U.S. Pat. No. 6,278,377, the disclosure of which is incorporated by reference herein) is particularly advantageous for economical achievement of clear and error-free transmission from the vehicle, while operating along a highway, to a remote receiver, particularly in speech-recognition mode. This use of network  34  facilitates location of button  58  in interior mirror assembly  16 . 
     Microcomputer  20  may receive memory information  70  over network  34  and actuate an actuator  72  to position reflective element  24 . Principles, disclosed in commonly assigned U.S. Pat. No. 5,796,176 entitled MEMORY MIRROR SYSTEM FOR VEHICLES, the disclosure of which is hereby incorporated herein by reference, may be utilized for communicating such memory information over network  34 . 
     Microcomputer  20  may also use network  34  to measure values of light sensed by light sensors  24 , supply drive signals to the electrochromic reflective element, and the like, on the network  34 . Partial reflectance levels may be communicated to exterior rearview mirror assemblies  12 ,  24  over network  34 . In this manner, if the interior digital electrochromic mirror system  18  develops a fault, incorrect information will not be transmitted to exterior rearview mirror systems. This also allows exterior reflective elements to have different peak voltages and provides more precise control over each of the mirror assemblies  12 ,  14 ,  16 . 
     Other functions may be controlled over network  34  such as remote keyless entry  74  and global positioning system information/navigational system as described in commonly assigned co-pending application Ser. No, 09/799,414, filed on Mar. 5, 2001, by McCarthy et al., entitled COMPLETE MIRROR-BASED GLOBAL-POSITIONING SYSTEM (GPS) NAVIGATION SOLUTION, now U.S. Pat. No. 6,477,464, the disclosure of which is hereby incorporated herein by reference. 
     In addition to placement at, on or in exterior rearview mirror assembly  18 , circuit board  61  may be positioned at a location (and preferably in a housing) separate from interior mirror assemblies, such as disclosed in commonly assigned U.S. Pat. No, 6,099,131 entitled ELECTRO-OPTIC MIRROR SYSTEM, the disclosure of which is hereby incorporated herein by reference. 
     Also, the concepts of the present invention provides a new and unique combination of a digital electrochromic mirror system, a vehicle accessory and a vehicle network when the vehicle accessory comprises a tire pressure monitoring/display system. 
     Changes and modifications in the specifically described embodiments can be carried out without departing from the principles of the invention which is intended to be limited only by the scope of the appended claims, as interpreted according to the principles of patent law including the doctrine of equivalents.

Technology Classification (CPC): 1