How NES Zapper or Duck Hunt Gun works?

The Duck hunt is very interesting game and the goal of game is to shoot ducks and then collect them with hunting dogs for this NES zapper gun or duck hunt gun is used. Then which technology is used? How it works? How much accuracy of system?  All these explained in this article.                     

So basically the duck hunt gun works on light sensing. The gun consists of button (the trigger) and a photodiode (light sensor).                                    

Duck Hunt Gun or NES Zapper

When we pull the trigger, the TV screen goes completely black for one frame. At this point game uses light sensor to sample black color which is reading from TV to give it reference point. Reference point is given to see ambient light of room and other thing that can vary greatly.

In next frame, the game causes the target area to turn white and the rest remaining black.

If gun’s photodiode detects shift from black to white that means we are aiming correctly at the target.

For the game with multiple targets at a given time, the same method is used except multiple target frames are shown.

So like that game will flash the black reference screen, then will flash for the targets, leaving rest of the screen black, then flashes next target, again leaving the rest of screen black , and so on.

The game knows which target is hit because light shift is detected.

More about NES zapper gun:
  •        It has ability to distinguish between multiple targets in one frame.
  •       In one frame system, it uses a signal from TV itself.
  •      The signal is in the form of pulses which signify the start of the horizontal and vertical retracing.
  •       With precise enough timing it is able to detect which target is being hit.
How does the light gun for video game?

The gun contains photodiode or a phototransistor in the barrel and a trigger switch.

The photodiode is able to sense the light coming from the screen.

 The output of the photodiode and switch is fed to the computer controlling the game.

For television horizontal and vertical retrace is used to align the picture on the screen.

The screen sends start of horizontal and vertical pulses, so the computer knows where the beam is located during each frame.

The computer uses two techniques to figure out target:

1.       The computer blanks the screen and then paints just the target object white.

2.       The computer blanks the screen and paints the entire screen white.

Single player video game:

A single player video game is having one input. This game usually played by one person.

Single player game are able to deliver certain game experience that are absent in multiplayer game.

Multiplayer video game:

In this more than one player can play the game.

Multiplayer games usually require players to share the resources using networking technology.

Can we play duck hunt on a new TV?

Duck hunt doesn’t work on modern LCD or OLCD TVs, so you can’t play the game unless you have an old CRT TV.

Why duck hunt can’t play on flat screen?

Because duck hunt game and zapper gun are calibrate to scan rates of tube TV’s, so the zapper can’t “see” the screen of modern TV.

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