Patent Publication Number: US-2004052086-A1

Title: Vehicle brake light system and method

Description:
FIELD OF THE INVENTION  
       [0001] The present invention relates to motor vehicle safety generally and more particularly to brake light actuation systems and methods.  
       BACKGROUND OF THE INVENTION  
       [0002] Brake lights have long been an essential safety feature of motor vehicles, indicating to a following driver that a vehicle in front of him is decelerating. In recent years brake lighting systems have been proposed which included a plurality of sequentially lighted brake lights and brake lights whose intensity indicates the extent of braking.  
       SUMMARY OF THE INVENTION  
       [0003] The present invention seeks to provide a new brake light system, which, it is believed, enhances the alert level to a following driver.  
       [0004] There is thus provided in accordance with a preferred embodiment of the present invention a brake light system including a braking action responsive switch, at least one braking indicator light and braking indicator light actuation circuitry responsive to the braking action responsive switch for initially illuminating the at least one braking indicator light to a relatively high level of illumination and thereafter reducing illumination of the at least one braking indicator light to a relatively low level of illumination.  
       [0005] There is also provided in accordance with a preferred embodiment of the present invention a brake light illumination method including:  
       [0006] responsive to braking action, initially illuminating at least one braking indicator light to a relatively high level of illumination; and thereafter  
       [0007] reducing illumination of the at least one braking indicator light to a relatively low level of illumination.  
       [0008] Preferably, the relatively high level of illumination is higher than a nominal level of illumination employed in most conventional brake light systems. Preferably the relatively low level of illumination is identical to the nominal level of illumination.  
       [0009] In accordance with one embodiment of the present invention, the braking indicator light actuation circuitry is operative to illuminate the at least one braking indicator light at the relatively high level of illumination for a first time duration and to illuminate the at least one braking indicator light at the relatively low level of illumination for a second duration. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0010] The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which:  
     [0011]FIGS. 1A and 1B are simplified illustrations of two operational states in the operation of the system and method of the present invention, an initial braking-high level brake light illumination and a continued braking-low level brake light illumination;  
     [0012]FIG. 2 is a diagram illustrating the variation in brake light illumination intensity as a function of time;  
     [0013]FIG. 3 is a simplified block diagram illustration of the system of the present invention; and  
     [0014]FIG. 4 is a schematic illustration of actuation circuitry employed in accordance with a preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT  
     [0015] Reference is now made to FIGS. 1A, 1B and  2  which are simplified illustrations of two operational states in the operation of the system and method of the present invention, initial braking-high level brake light illumination and continued braking-low level brake light illumination.  
     [0016] In accordance with a preferred embodiment of the present invention, when braking action is not taking place, brake lights  10  are not illuminated. Upon the onset of braking action, (t o ) as illustrated in FIG. 1A, the brake lights  10  are illuminated to a relatively high level of illumination designated “B” in FIG. 2, preferably, significantly higher than the conventional level of illumination of brake lights in conventional vehicles.  
     [0017] As seen in FIG. 1B, preferably after a predetermined time duration, typically approximately one second, the level of illumination of the brake lights is reduced, preferably to the conventional nominal level designated “D” in FIG. 2 (t 1 ). Preferably the relatively high level of illumination is approximately twice the electrical power level of the relatively low level of illumination (n˜2).  
     [0018] It is to be appreciated that the functionality described hereinabove with respect to FIGS. 1A, 1B &amp;  2  provides increased awareness of braking on the part of a following driver, since that driver senses multiple transitions between intensities at multiple levels rather than just a single off-on transition, as in the prior art.  
     [0019] Reference is now made to FIG. 3, which is a functional block diagram of the system and method of a preferred embodiment of the present invention. As seen in FIG. 3, a braking action responsive switch  20 , preferably associated with a vehicle braking system, operates at least one braking indicator light  22 , such as light  10  in FIGS. 1A &amp; 1B, via braking indicator light actuation circuitry  24 .  
     [0020] Circuitry  24  is responsive to the braking action responsive switch  20  for initially illuminating the at least one braking indicator light to a relatively high level of illumination and thereafter reducing illumination of the at least one braking indicator light  22  to a relatively low level of illumination.  
     [0021] Preferably, the relatively high level of illumination is at least twice as high as a nominal level of illumination employed in most conventional brake light systems.  
     [0022] In accordance with one embodiment of the present invention, the braking indicator light actuation circuitry  24  is operative to illuminate the at least one braking indicator light  22  at the relatively high level of illumination for a first time duration and to illuminate the at least one braking indicator light  22  thereafter as long as the brakes are engaged.  
     [0023] Reference is now made to FIG. 4, which is a schematic illustration of actuation circuitry, such as circuitry  24  (FIG. 3) employed in accordance with a preferred embodiment of the present invention. For the sake of conciseness, the circuit parameters, which are clearly shown in FIG. 4 are not here repeated in prose. The designations J 1 -J 4 , which appear in FIG. 3, also appear in FIG. 4 to facilitate understanding of the relationship between FIGS. 3 and 4.  
     [0024] It is appreciated that the present invention may be carried out by circuitry other than that shown in FIGS. 3 and 4. For example, a pair of bimetallic switches may be employed to cause brake light activation to be initially at a relatively high level and thereafter at a relatively low level.  
     [0025] It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove as well as variations and modifications which would occur to persons skilled in the art upon reading the specification and which are not in the prior art.