US 5,793,420 · Granted 1998-08-11
The 1998 Multi-Camera Patent That Invented Dashboard Recording
Imagine a system where multiple cameras around your car automatically start recording when you turn a corner or detect motion nearby. This patent describes exactly that: a smart relay box that switches between three or more cameras, routes their footage to a recorder, and auto-triggers recording based on turn signals or motion detection.
The plain-English version
What it protects
The claim covers a vehicle video system with multiple cameras (at least three) connected to a central relay device that intelligently routes video signals to either a recorder or monitor based on control signals. Specifically protected is the auto-trigger mechanism that activates recording when a turn signal is engaged, plus the cross-vehicle motion detection feature where one car's sensor can trigger another car's camera to record. The system architecture drawing power from the vehicle's battery is also claimed.
Why it matters
Filed in 1996 and granted in 1998, this patent arrived at the early frontier of vehicle surveillance technology, well before dash cams became standard consumer equipment. The innovation of automatic triggering based on vehicle signals (like turn activation) and inter-vehicle motion detection shows early thinking about hands-free, context-aware recording. This foundational approach to multi-camera coordination in vehicles influenced how modern dash cam and security systems prioritize which footage to save.
Real-world use
When you get into a car equipped with this system and make a sharp turn, the cameras automatically start recording without you touching anything—the turn signal itself tells the system to capture what's happening around the vehicle.
Original USPTO abstract
A vehicle video system including at least three video cameras electrically connected to a video signal relay device which directs video signals generated by each of the video cameras to either a video recorder or a monitor depending upon switching signals received to the video signal relay device. A video camera is automatically triggered to commence recording upon activation of a turn signal of a vehicle on which the system is deployed. A motion detector deployed on one vehicle can trigger a video camera deployed on another vehicle to commence recording. The system draws power from a battery of the vehicle.
Patent details
- Publication number
- US 5,793,420
- Filing date
- 1996-02-20
- Grant date
- 1998-08-11
- Assignee
- Schmidt; William P.
- Inventor(s)
- SCHMIDT; WILLIAM P.
- CPC class
- H04N5/77
Want to file your own patent?
If you're designing the next generation of automotive safety cameras, scan your prototype concept through our free patent search tool to spot existing claims in the automotive-gadgets space.
Free patentability scan