Begin by affixing an LED display screen to the rear-view window of a vehicle, in full view of the driver in the car just behind. The purpose of this gadget is to signal one’s appreciation to the driver behind when he or she accommodates your lane change. Blinking LEDs spell out the word “arigato” (“thanks”). You can also use it to spell out a fun message to drivers around town.

Create an 8x8 LED screen matrix to suit a 0.5m x 1.0m rear-view window.
Using small-sized LED bulbs will facilitate a layout preserving rear-view vision.
The overall screen size will be large enough to allow the driver behind to read its message.

The script scrolls by horizontally, enabling display of even a long message.
This novel gadget will ensure that your message reaches its target.
While designed to spell out “arigato” (“thanks”), the gadget can be adapted to flash the time or temperature, or even a witty thought.
There are some 81 million cars on the road in Japan, and 1.2 billion worldwide.
This gadget is sure to please all of those drivers as well as all those who are out and about.
Until now, most drivers used their emergency blinkers to say thanks.
From here on out, drivers may use the “smile signal” to transmit their appreciation.

I hope the rear-view window will help communicate a bit of charm and put a smile on drivers and fellow citizens.

The display
Create an 8x8 LED screen matrix on a 0.5m x 0.5m display.
Arrange the LEDs into a square block (6cm x 6cm).
This display can easily flash a message while the car is in motion.

Message content
There are two separate messages. 
The first spells out “arigato” (“thanks”) and with a smiley face.
The second spells out “Traffic jam. Hang in there!” 
Each message has its own button on the dashboard, just press a button to send a message! You can easily add your own message as well.

Car inspections
Car inspections prohibit stickers attached to the front, driver-side and passenger-side windows. So, attaching the LED matrix to the rear-view window presents no problem. It is the perfect gadget for a car-oriented society.

Power sourcing
The gadget operates on a USB power supply, such as a USB charger inserted in the vehicle’s cigarette lighter.  To avoid extra wiring, use a USB mobile battery instead.

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