The patent says any of the lights can remain on for a period of time, blink on and off, or fade from bright to faint.

The eyelids can close in any direction - top to bottom, bottom to top and diagonally.

The eyebrow shape can change, and the brows, lids and tears can be featured in different colors, the patent says.

Data on the state of the car, the road and the driver is collected and stored in the car's computer, which attributes points to certain factors - like "the occupant reacts to reckless cutting in," or speed, handling angle or brake pressure - that might contribute to an angry response.

When a sufficient number of points are accumulated to indicate anger, the computer's software will trigger a reaction in the car's appearance.

"The state of angry will be changed either over time or in response to soothing input supplied by the occupants," the patent says.

"When the number of points is reduced below the threshold value, the vehicle no longer shows angry."

The patent includes a chart that shows how the car might display a number of emotions.

It shows categories that correlate driver reaction, road or car condition to color and position of features like the "eyebrow," the antenna, the headlights and the vehicle height.

For anger, the hood lighting color glows red while the eyebrow lights up and the headlights, antenna and height are in standard position.

But if the driver is joyful, the car may "wink" to let another car go first by changing the hood lighting and the eyebrow to orange, shading the headlight so it appears half-closed and causing the antenna to vibrate from left to right as if it were wagging.

The chart also indicates that a car with mechanical trouble might "cry" by displaying dark blue hood lighting, a shaded headlight, a lit eyebrow and a blinking "tear" light.

And if the "sudden appearance of a vehicle or pedestrian causes sudden braking," the car will express surprise by having its hood lights turn orange, its eyebrows light up red, the headlights shaded and the vehicle height lowered in the rear.

The patent says the inventors chose the colors, shadings and positions "in consideration of human psychology."

It explains that "some reactions may be expressed using warm colors," and cites orange as appropriate for winking, feeling fine or looking around, and red as the right choice for anger or surprise.

"Meanwhile, some other reactions such as sad, crying, fearful and so forth may be expressed using cold colors," like green or blue, the patent says.

The inventors also say their idea, which was awarded Patent No. 6,757,593, is not just for cars.

They note it could also be used with motorcycles, ships or aircraft.

Patents may be viewed on the Web at www.uspto.gov or may be ordered through the mail, by patent number, for $3 from the Patent and Trademark Office, Washington, D.C. 20231.