You can freely build on How the First Home Video Game Console Worked

What this patent covers

The patent describes an analog electronic system that connects to a standard television's antenna terminals to display interactive games. It generates three main visual elements: two 'hitting' symbols (controlled by players) and one 'hit' symbol (a ball). The system uses horizontal and vertical sync generators to create square pulses. By delaying these pulses using voltage controls, the system positions the symbols on the screen. A critical component is the coincidence circuit, which detects when a player's hitting symbol overlaps with the ball symbol. When this overlap occurs, the circuitry automatically reverses the ball's direction, simulating a bounce in games like table tennis or volleyball.

What is now free to use

All 1 claims of US 3659285 are in the public domain. Specifically:

The 1 dependent claim add narrowing limitations and are also free.

What is NOT covered

Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.

• Does not cover digital game systems that use microprocessors, software code, or pixel framebuffers to render graphics.

• Does not cover games that display complex, multi-colored sprite graphics instead of simple geometric dots or blocks.

• Does not cover systems that require a specialized computer monitor rather than a standard broadcast television receiver.

• Does not cover collision detection calculated via software coordinate checks rather than analog hardware coincidence gating.

Who is building on this today

While modern console makers like Sony, Microsoft, and Nintendo use digital microprocessors rather than Baer's analog pulse-delay circuits, the fundamental concept of hardware-level collision detection and interactive video feeds remains a cornerstone of real-time graphics rendering.

Products built on expired version of this technology

How to cite this patent in your documentation

Sanders Associates Inc. US Patent 3659285. Television gaming apparatus and method. Granted 1972, expired 1989. Now in the public domain.

Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.

PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.