Abstract:
A vehicle lighting control system according to the present invention includes an electronic module connected to the vehicle lighting and windshield wiper systems which provides daytime running lamps (high beams at fifty percent power) during normal, daytime operation a full complement of vehicle lights including the running lights and low beam headlights at full power, when the wiper system is activated. The full complement of lights is deactivated by turning off the ignition switch or turning the wiper switch to the “OFF” position, turning the headlight switch to the “ON” position, and then turning the headlight switch to the “OFF” position. As such, the driver is prevented from inadvertently shutting off the full complement of lighting in a low visibility situation. The present invention also incorporates an automatic delay feature which allows the driver to wash the windshield in non-rain conditions without activating the full complement of lights. In the event the windshield wipers continue to operate past the thirty second time period, the system activates the full complement of lights.

Description:
This Application claims benefit of Provisional Application 60/056,291 filed Sep. 3, 1997. 
    
    
     The present invention relates generally to a system for use on motor vehicles having Daytime Running Lights (DRLs). More particularly, the present invention coordinates the operation of the DRLs with the operation of the vehicle&#39;s headlights, taillights, running lights, and windshield wipers. 
     BACKGROUND OF THE INVENTION 
     Many of today&#39;s motor vehicles are equipped with a safety feature known as Daytime Running Lights (DRLs) in which the headlights are activated at reduced power whenever the ignition is on. DRLs greatly increase the visibility of the vehicle in all conditions, although the increased visibility is most advantageous in low light conditions, such as during rainy or heavily overcast days. Tests have shown that the improved visibility of DRL equipped vehicles substantially decreases the likelihood that the vehicles will be involved in accidents. 
     Unfortunately, DRLs also tend to increase the likelihood that drivers will forget to enable the vehicle&#39;s full power headlights when the ambient light decreases to a point that full power headlights are necessary. For example, a driver operating a DRL equipped vehicle during the day may forget to switch the headlights to full power when it gets dark or begins to rain because the light provided by the reduced power headlights seems sufficient under the gradually changing ambient lighting conditions. As a result, the vehicle is less visible to other vehicles and the road is insufficiently illuminated for the driver. Also, in the rain, the DRL equipped vehicle is not visible from the rear because DRLs do not activate the taillights or other running lights. The driver&#39;s field of vision and depth perception may be adversely affected, yet the driver may remain unaware of his impaired visibility, and believe that the full compliment of full power headlights, taillights, and running lights are activated. On many vehicles, such as large commercial trucks and tractor-trailer rigs, the consequences of running on DRL&#39;s in low visibility conditions can create accident prone situations. 
     SUMMARY OF THE INVENTION 
     The present invention provides a vehicle lighting control system which controls the operation of the DRLs, the headlights, the taillights, and the running lights in relation to the driver&#39;s selection of lighting and windshield wiper control settings so as to ensure adequate lighting under various driving conditions and to prevent the driver from inadvertently failing to conform his lighting selection to the current driving conditions. The present control system provides DRLs (high beams at fifty percent power) during normal, daytime operation. When the windshield wipers are activated, the DRL circuit is deactivated, and the full complement of vehicle lights are activated, i.e. the taillights, running lights, and low beam headlights at full power. Moreover, the driver retains full control over the lighting system, and may override the system to switch to full power lights at any time by simply activating the normal headlight switch. 
     As a safety feature, the driver must consciously deactivate the full lighting system after it is activated by the windshield wiper switch. The driver may deactivate the system by turning off the ignition switch or by switching back to the DRL mode by turning the wiper switch to the “OFF” position, turning the headlight switch to the “ON” position, and then turning the headlight switch to the “OFF” position. Alternatively, the driver can switch back to DRL mode by depressing an optional “kill” switch. As such, the driver is generally prevented from inadvertently shutting off the full complement of lights in a low visibility situation. 
     The present invention also incorporates an automatic thirty second delay feature that allows the driver to wash the windshield in non-rain conditions without activating the headlights, taillights, and running lights. In the event the windshield wipers continue to operate past the thirty second time period, the system activates the full complement of lights. 
     Thus, a motor vehicle equipped with the lighting control system of the present invention is more visible at all times than are comparable vehicles equipped with the standard DRL systems. The control system of the present invention also ensures that drivers will not inadvertently operate under low light conditions with inadequate lighting, and will also ensure that drivers will not inadvertently deactivate the full complement of vehicle lights at the wrong time. 
     Accordingly, it is an object of this invention to provide a vehicle lighting control system that integrates the control of DRLs, headlights, taillights, running lights, and windshield wipers into a single integrated system. 
     It is another object of this invention to provide a control system for motor vehicles that automatically activates the full power lighting system of the vehicle when the windshield wipers are activated. 
     A further object of this invention is to provide a lighting control system for motor vehicles that essentially prevents inadvertent deactivation of the full power lighting system. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects and advantages of the present invention, and the manner of attaining them, will become more apparent and the invention will be better understood upon reading the following description in conjunction with the drawings wherein: 
     FIG. 1 is a fragmented, top plan view of the control system of the present invention mounted to a vehicle; 
     FIG. 2 is a conceptual view of controls for operating the present invention; 
     FIG. 3 is a schematic diagram of a control system according to the present invention connected to a vehicle lighting and windshield wiper system; and 
     FIG. 4 is a flow diagram of the operation of the system of FIG.  3 . 
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present invention. 
     DESCRIPTION OF THE INVENTION 
     The embodiments disclosed below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings. 
     FIG. 1 shows the present vehicle lighting control system which includes a box or module generally designated  10  mounted to a vehicle  12  having low beam headlights  14 , high beam headlights  16 , (which also serve as daytime running lamps as will be further described below), taillights  18 , running lights  20 , panel lights  22  mounted to the dash board  24 , and windshield wipers  26 . As best shown in FIG. 2, dash board  24  includes standard control switches and buttons including an ignition switch  28 , a headlight switch  30 , a high/low beam selection switch  32 , a windshield wiper switch  34 , a panel light intensity control  36 , a wiper speed control  38 , and a momentary-on, windshield wiper wash button  40 . Wire harnesses  42  interconnect the various controls, system module  10 , and the vehicle lighting system and windshield wiper system. 
     FIG. 3 shows an embodiment of the present system  10  interconnected with a vehicle lighting system and a vehicle windshield wiper system. The vehicle ignition switch  28  enables the system as described below. Ignition switch  28  is connected on one side to battery power and on the other side to the vehicle ignition system (not shown), wash button  40 , wiper switch  34 , and pin  45  of module  10 . When depressed, wash button  40  connects ignition switch  28  output to a wash motor  44  for actuating a pump (not shown), and module pin  47 . When wiper switch  34  is switched into a selected one of its “ON” positions, it connects the ignition switch output to a wiper motor  46  and pin  49 . 
     The lighting system includes headlight switch  30  which switches system power (generally designated +V) at its input between an “OFF” pole, a “PARK” pole, and an “ON” pole. The “PARK” pole is connected to the normally closed (NC) pole of relay  48  and the NC pole of relay  50 . The normally opened (NO) poles of both relays  48 ,  50  are connected to V+. Headlight switch  30  “ON” pole is connected to the coil high side of relays  48 ,  50  to apply V+ when headlight switch  30  is in the “ON” position, thereby activating the relays and connecting the relay common poles to V+. The “ON” pole is also connected to pin  52  of module  10 . 
     The common pole of relay  50  is connected to the wiper of intensity control  36 . Panel lights  22  (only one shown) are connected between intensity control  36  and ground. The common pole of relay  48  is connected to the NC pole of relay  54  which switches power to running lights  20  (only one shown). The coil high side of relay  54  is connected to output pin  56  of module  10 . Also, the coil high sides of relay  58 , left headlight relay  60 , and right headlight relay  62  are connected to V+. The coil low sides of left and right headlight relays  60 ,  62  are connected to pin  64  of module  10 . A dimmer switch  66  is connected between pin  64  and pin  68 . The coil low side of relay  58  is connected to pin  70  of module  10 . The left low beam  14  is connected between the NC pole of relay  60  and the high beam  16 , which is connected to the NO pole of relay  60 . The right side lights are similarly connected. The node between the left side headlights  14 ,  16  is connected to the node between the right side headlights  14 ,  16 , and routed to the common pole of relay  72 . The NC pole of relay  72  is connected to ground and the NO pole is opened. Relay  72  is activated by the signal from pin  74  of module  10 . The common pole of left relay  60  is connected to output pin  76 . The common pole of right relay  62  is connected to the common pole of relay  58 , which is normally connected to pin  78  of module  10 . 
     Module power is connected to module  10  at pin  100  and ground at pin  102 , as shown in FIG.  3 . Power is routed internal to module  10  to the common poles of relays  104 ,  106 ,  108 ,  110 , and  112 . Power is also switched into module  10  from ignition switch  28  through pin  45 . Pin  45  is connected to the coil high side of relays  106  and  110 , the common pole of relay  114 , and the emitter of transistor  116 . Power from headlight switch  30  is routed through pin  52  to the coil high side of relays  104  and  108 , the gate of transistor  118  through diode  120  and resistor  122 , and the base of transistor  116  through diode  124  and resistor  126 . The NO pole of relay  104  and the NO pole of relay  106  are connected to output pin  76 . Relays  108  and  110  are similarly connected to output pin  78 . The NO pole of relay  112  is connected to pin  74  and enables relay  72  as described herein. 
     Pin  47  from wash button  40  is connected through diode  128  to RC delay network  130  and diode  132 . Network  130  provides a time delay, for example, thirty seconds, before charging to a level required to actuate transistor  118  as explained below. Diode  132  is connected to the common pole of relay  134 . The NC pole of relay  134  is connected to a voltage divider network including resistors  136 ,  138  which is connected to the gate of transistor  118 . The source of transistor  118  is supplied by pin  49  (through diode  140 ) which is also connected to the NO pole of relay  114 . The drain of transistor  118  enables relay  114  at its coil high side and is connected to output pin  56 . 
     Pins  70  and  64  are connected the NO pole of relay  142  through diodes  144  and  146 , respectively. The common pole of relay  142  is connected to ground. The coil high side of relay  142  is connected to the NC pole of relay  114  and the low side is connected to the NO pole of relay  148 . The NC pole of relay  148  is connected to pin  68 , and the common pole is connected, along with the coil high side, resistor  150 , and the anode of diode  152 , to ground. The coil low side of relay  148  is connected to the cathode of diode  152  and the collector of transistor  116 . Finally, resistor  150  is connected to the base of transistor  116 . 
     Mode of Operation 
     FIG. 4 is a flow diagram representing the operation of the present system  10 . System  10  is enabled by switching ignition switch  28  to the “ON” position. High beams  16  are automatically placed in daytime running lamp (DRL) mode. As shown in FIG. 3, when ignition switch  28  is switched “ON,” power is applied to pin  45  (through relay  114 ) to activate relay  142 , thereby connecting the coil low side of relays  60  and  62  to ground through diode  146 , and the coil low side of relay  58  to ground through diode  144 . Since the coil high side of each relay  58 ,  60 ,  62  is connected to V+, the relays are activated and power is applied across high beams  16  in series from the V+, through relay  106  (activated by power from ignition switch  28 ), pin  76 , relay  60 , left high beam  16 , right high beam  16 , relay  62 , to ground through relay  58 . 
     The normally present connection to ground through relay  72  between left and right high beams  16  is broken (thereby connecting the lights in series) because activation of relay  142  also activates relay  112 . Relay  142  is activated because transistor  116  is biased in a normally “ON” configuration so that power from ignition switch  28  flows through transistor  116  to the coil low side of relay  148 . The coil of relay  148  provides a path to ground, and the relay is sealed by diode  152 . When relay  148  switches, relay  142  is activated because its coil low side is connected to ground. Since relay  142  and relay  112  are coupled for simultaneous operation, relay  112  switches position to provide power to the coil high side of relay  72 . Relay  72  is thus activated and the common pole is switched to the NO pole. 
     With high beams  16  connected in series, each light receives one-half the power normally provided for full brightness. Thus, high beams  16  shine at half power to provide the DRL function. The system remains in this mode of operation so long as headlight switch  30  is in the “OFF” position and wiper switch  34  is in the “OFF” position. 
     As shown in FIG. 4, when headlight switch  30  is placed in the “PARK” position, panel lights  22  and running lights  20  are enabled. Power to panel lights  22  is provided from headlight switch  30  through the NC pole of relay  50  to the wiper of intensity control  36 . The intensity of panel lights  22  depends upon the position of the wiper according to principles well known in the art. Running lights  20  are powered through the NC pole of relay  48  and the NC pole of relay  54 . As the flow diagram suggests, system  10  will remain in this mode of operation until either wiper switch  34  is activated or the position of headlight switch  30  is changed. 
     If wiper switch  34  is moved to the “ON” position, the system activates low beams  14  instead of the DRLs, and enables windshield wipers  26 . Power is supplied through wiper switch  34  to wiper motor  46  which controls the wipers in the standard manner. Power also flows through pin  49 , across diode  140 , and into the source of transistor  118  which is forward biased “ON.” The drain activates relay  114  which connects battery power to the source of the transistor. A sealing circuit is thereby provided wherein power will remain continuously applied to the source of transistor  118 , even after wiper switch  34  is switched off. Activation of relay  114  deactivates relay  142 , which simultaneously deactivates relay  112  as explained above. When relay  142  opens as shown in FIG. 3, the path to ground for relays  58 ,  60 , and  62  is broken, thereby deactivating those relays. Deactivation of relay  112  deactivates relay  72  which then supplies a common path to ground for the node connecting the left high and low beam headlights and the node connecting the right high and low beam headlights. The drain of transistor  118  also provides power to the coil high side of relay  54  which switches to V+ to power running lights  20 . 
     Power from ignition switch  28  energizes relays  106  and  110  which connect V+ to left relay  60  (through pin  76  of module  10 ) and relay  58  (through pin  78  of module  10 ), respectively. Relay  58  connects V+ to right relay  62 . Power flows through left low beam  14  and right low beam  14  to ground through relay  72 . Thus, as indicated by FIG. 4, running lights  20  remain activated and low beams  14  are activated. 
     The system continues to operate as described above until wiper switch  34  is turned to the “OFF” position. Of course, if wiper switch  34  is turned to the “HI” or “INT” position, the speed of motor  46  is adjusted accordingly. When wiper switch  34  is switched to the “OFF” position, power is removed from motor  46  thereby disabling wipers  26 . However, power remains connected to the source of transistor  118  from relay  114  which has been sealed in an activated state as explained above. Thus, transistor  118  drain continues to activate relay  54  and running lights  20 . Headlights  14  remain powered until the user completes a cancellation sequence wherein wiper switch  34  is switched to the “OFF” position and headlight switch  30  is switched first to the “ON” position, and then to the “OFF” position. When wiper switch  34  is off and headlight switch  30  is on, power is applied from headlight switch  30  through pin  52 , diode  124  and resistor  126  to the base of transistor  116 . Power is similarly applied through diode  120  and resistor  122  to the gate of transistor  118 . Both transistors are disabled. Vehicle dimmer switch  66  is used to switch between low and high beams. When headlight switch  30  is returned to the “OFF” position, the system returns to DRL operation as described above. Obviously, all lighting and wiper operation may be stopped simultaneously at any time by switching ignition switch  28  to the “OFF” position. Additionally, an optional “kill” switch could readily be included to return the system to DRL mode. 
     As shown in FIG. 4, if after ignition switch  28  is switched on, headlight switch  30  is switched to the “ON” position rather than the “PARK” position, panel lights  22  and running lights  20  are activated and either the low beams headlights  14  or the high beam headlights  16  are activated. Panel lights  22  are activated when power from headlight switch  30  is applied to relay  50 . The intensity of the lights is adjustable using intensity control  36 . Running lights  20  are powered by relay  48  which, once activated, supplies power through the NC pole of relay  54 . Headlight switch  30  also deactivates relay  148  by applying power to the base of transistor  116  through diode  124  and resistor  126 . Consequently, relay  142  is deactivated, thereby removing the path to ground at the coil low side of relays  58 ,  60 , and  62 . These relays return to their normally closed positions shown in FIG.  3 . Deactivation of relay  142  simultaneously deactivates relay  112 , which deactivates relay  72  to provide a path to ground for the nodes connecting the low beams to the high beams. Power from switch  30  also activates relays  104  and  108 . Relay  104  closes and supplies power (through left relay  60 ) to left low beam  14 . Relay  108  similarly supplies power (through relay  58  and right relay  62 ) to right low beam  14 . 
     As shown in the flow diagram of FIG. 4, system  10  remains in normal headlight operation until the operator switches headlight switch  30  to “PARK” or “OFF,” switching the system to DRL mode, or switches wiper switch  34  to “ON,” activating wipers  26 . As should be apparent from the foregoing during normal headlight operation, when the operator switches wiper switch  34  to the “ON” position, only wipers  26  are activated since panel lights  22 , running lights  20 , and headlights  14  are already activated. If the wipers are activated while the system is operating in normal headlight mode, the cancellation sequence to return to DRL mode simply requires the operator to switch wiper switch  34  to “OFF,” then switch the headlight switch  30  to either “PARK” or “OFF.” 
     Referring again to the flow diagram of FIG. 4, an additional ignition sequence occurs when ignition switch  28  is switched on (which results in DRL mode as explained above), headlight switch  30  is left off, and wiper switch  34  is switched on. Under these circumstances, running lights  20  are powered through relay  54  which is activated by transistor  118 . The DRL mode is disabled when relay  114  provides the sealing circuit for transistor  118 , deactivating relays  142 ,  112 ,  58 ,  60 ,  62 , and  72 . Low beams  14  are then activated as power from relays  106  and  110  flows through low beams  14  and relay  72  to ground. 
     If headlight switch  30  is later switched to “PARK,” panel lights  22  are activated as explained above. If, instead, headlight switch  30  is switched to “ON,” the panel lights are activated and the operator can switch between low beams  14  and high beams  16  by activating switch  66 . In any event, after wiper switch  34  is switched to the “OFF” position, the operator can return to DRL mode by either switching the headlight switch  30  to the “PARK” or “OFF” position (if the headlight switch was in the “ON” position when the wipers were switched off) or switching the headlight switch first to the “ON” position and then to the “PARK” or “OFF” position (if switch  30  was in the “OFF” position when switch  34  was switched off). 
     An additional feature of the present system is the wash mode (not shown in the flow diagram of FIG.  4 ). When the operator cleans the windshield or otherwise temporarily operates the wipers  26 , it is desirable to remain in DRL mode (when outdoor lighting conditions are good). System  10  provides a time period following operation of wash button  40  during which the operator may activate wipers  26  without activating the full complement of lights (i.e., low beams  14 , running lights  20 , and panel lights  22 ) as would normally occur upon activation of wiper switch  34 . When wash button  40  is depressed, power from ignition switch  28  flows through diode  128  to the RC time constant provided by block  130  and to the gate of transistor  118  through diode  132 , relay  134 , and resistor  136 . Transistor  118  is disabled. RC time constant  130  is charged and continues to apply sufficient voltage to the gate of transistor  118  when wash button  40  is released. RC time constant  130  applies such a voltage for a predetermined time period (for example, thirty seconds) according to principles commonly known in the art. During this time period, when wiper switch  34  is switched to the “ON” position, power is provided to the source of transistor  118  as explained above, but no power is provided to relay  114  since transistor  118  is disabled. As such, relay  114  continues to enable relay  142  (and relay  112 ) to provide the DRL circuit described above. If, after the predetermined time when power to the gate of transistor  118  is terminated to enable the transistor, wiper switch  34  is in the “ON” position, power flows through transistor  118  to activate relay  114 , thereby sealing transistor  118  in conducting operation and activating the full complement of lights as described above. 
     A photo cell  160  connected to an appropriate power source and exposed to ambient light is connected into the control system at the source of transistor  118  and between diodes  128  and  132 . When it gets sufficiently dark, photo cell  160  first disables transistor  118  for a timed delay thru RC time constant  150 . After the delay (used to accommodate momentary periods of darkness), transistor  118  is enabled and power flows through the transistor to activate relay  114  and produce the full complement of lights. 
     As should be apparent from the foregoing, the present system could be implemented using various electrical components other than those depicted in FIG. 3, including a programmable or application specific integrated circuit. Furthermore, while this invention has been described as having a preferred design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.