Background of the Invention
This invention pertains to a device which displays the speed of an oncoming vehicle and, more particularly, to a highly visible, dual-color display indicative of an oncoming vehicle's speed and whether the vehicle is exceeding a threshold speed, e.g., the posted speed limit for that area.
Vehicle speed display devices are known. In such devices, a radar is mounted in a housing positioned along a roadway. As a vehicle approaches, the vehicle's speed is measured and displayed. One such device is as shown in U.S. Pat. No. 5,231,393 to Strickland. Some systems utilize flashing lights or other messages, apart from the actual vehicle speed display, to attract the driver's attention. One such device is shown in U.S. Pat. No. 3,544,958 to Carey et al.
One problem with past devices is that the driver's attention is not focused on the actual speed display. The flashing lights and other messages can divert the driver's attention away from the actual speed display which defeats the purpose of the device, particularly if the driver does not take any corrective action. None of these devices incorporates a speed display that changes color and flashes upon the vehicle's speed exceeding a threshold speed, e.g., a road's speed limit.
It is desirable to provide a highly visible dual-color display that displays the vehicle speed in a constant, relatively subdued color when below a selected threshold speed limit, but displays the speed in a flashing, accentuating color upon the vehicle exceeding the threshold speed. In this manner, the attention of a vehicle driver will be focused on the speed, particularly when exceeding the speed limit. Vehicle drivers, exceeding the threshold speed, e.g., the posted speed limit, are thus given a highly visible warning so that corrective action can be taken.
Summary of the Invention
It is therefore the primary object of the present invention to provide a highly visible, dual-color vehicle speed display of a vehicle's measured speed.
A further object of the present invention is to provide a device, as aforesaid, which displays a vehicle speed in either first or second colors according to the vehicle's speed relative to a preselected threshold speed.
Another important object of this invention is to provide a device, as aforesaid, which flashes the vehicle speed when the measured speed exceeds a preselected threshold speed and changes color to direct the vehicle driver's attention to the excessive speed.
These and other objects of the invention are achieved by an apparatus which measures the speed of an approaching vehicle and then compares the measured speed to a user preset threshold speed limit, e.g., the posted speed limit for the road of vehicle travel. If the measured speed is less than or equal to the preset threshold speed, the vehicle's speed is shown in a first color at a steady state on a highly visible screen display. If the measured speed is greater than the preset threshold speed, the vehicle's speed is shown in a second, flashing or otherwise accentuated color on the screen display. The use of the first relatively subdued display and the second accentuated, attention grabbing display more readily focuses the driver's attention on the fact that the threshold speed is being exceeded.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, a now preferred embodiment of this invention.
Brief Description of the Drawings
FIG. 1 is a perspective view of a radar trailer showing the dual-color display;
FIG. 2 is a functional block diagram of the display system illustrating the interfaces of the major components;
FIG. 3 is a diagrammatic view showing the first set of lights as circular indicia and a second integrated set of lights as square indicia; and
FIG. 4 is a flow chart of the software that controls the display settings.
Description of the Preferred Embodiment
Turning more particularly to the drawings, FIGS. 1 and 2 illustrate a radar trailer 100 with a releasable speed limit sign 110. Speed limit sign 110 shows the legal speed limit for a particular location. Radar transparency 120 corresponds to the placement of a radar gun 140 housed within radar trailer 100. Screen display 130 which is mounted in trailer 100 exhibits the speed of a vehicle measured by radar gun 140 or by other speed measuring devices, e.g., a laser based speed measurement system.
The violation alert speed device includes a radar gun 140, a mode selection switch 150, and a violation speed selection switch 152 connected to a display driver 160 which is capable of inserting a preselected threshold speed into the to-be described program logic, e.g., the posted speed limit for the road of vehicle travel. (We refer to such speed herein as the violation speed although it is understood that the threshold speed may be indicative of another speed parameter.) Mode selection switch 150 is a two-position toggle switch. Violation speed switch 152 is a three-position, center-return momentary switch. The vehicle speed output of display driver 160 is then transferred to display 130 in either of two modes. Display 130, shown in FIG. 3, is preferably composed of two sets of light emitting diodes (LEDs) capable of exhibiting at least two colors in at least a constant and a flashing mode. The color of the first set of LEDs 132 associated with the constant mode is preferably amber and the color of the second set of LEDs 134 associated with the flashing mode is a more accentuated color, preferably red. The display 130 is at least approximately 18 inches high. An internal power source, e.g., a battery, provides the necessary power.
FIG. 4 illustrates a flow chart of the display driven program that compares the speed data and then processes the speed display data for delivery to the dual-color display 130. Each processing and decision block is identified in the flow chart by a numerical designation from 1 to 8.
When trailer 100 is set up alongside a roadway, a speed limit sign 110 is placed on trailer 100 showing the speed limit for the particular roadway. The mode selection switch 150 is moved to the "set" position. The violation speed selection switch 152 is toggled up or down to increment or decrement the violation speed respectively. Once the desired violation speed is set, the mode selection switch 150 is moved to the "run" position.
When an approaching vehicle is detected, the vehicle's speed from the radar gun 140 is read (block 1) and compared to a speed corresponding to preset violation speed switch 152 (block 2). If the radar speed is less than or equal to the preset violation speed (block 3) the amber LED display 132 is turned on (block 4) and display flashing is set to off (block 5). The display driver includes means for converting the read speed from radar gun at 1 into a signal which will energize a selected number of lights in either display 132, 134 so that the appropriate 0-9 digit will be displayed. Various manners of converting signals to numerical information may be used so as to digitally display the measured speed between 00-99 m.p.h. Processing then continues (block 8) and starts over with the next speed measured by the radar gun 140. If the radar speed is greater than the preset violation speed (block 3) then the red LED display 134 is turned on (block 6) and display flashing is set to on (block 7). The measured violation speed is so displayed at 130 in an accentuated state relative to the subdued state when the violation speed has not been exceeded. Again, processing continues (block 8) for the next measured speed from radar gun 140.
It is understood that the above program may be in the form of a microprocessor which receives the measured speed signal from the radar gun or other speed measurement device and compares the vehicle speed to the preselected violation speed. Upon a comparison being made of the vehicle speed to the preselected violation speed, the display driver 160 will cause the speed to be displayed in either a first mode, i.e., a constant display of a first amber color or a second mode which accentuates the speed display, e.g., a flashing red color. Those skilled in the art can arrive at apparatus to arrive at the above display so as to display the measured vehicle speed in the amber and/or flashing red modes as above described.
Alternatively, it is understood that a single color display may be used which displays a vehicle's speed below the violation speed in a constant mode, and which displays a vehicle's speed exceeding the violation speed in a flashing mode. It is also understood that other forms of first and second speed displays may be used so that the second mode is a more attention focusing display than the display in a relatively subdued first mode.
It is to be understood that while a certain now preferred form of this invention has been illustrated and described, it is not limited thereto except insofar as such limitations are included in the following claims and allowable functional equivalents thereof.