This was the world's first Lens-Shutter 35mm autofocus camera. It used a triangulation system with a near-infrared emitting diode (IRED).
The active AF system had the IRED emit a near-infrared beam so its reflection was received by a pin photo diode.
When the shutter button is pressed halfway, the IRED emits a near-infrared beam on the subject. The beam reflected by the subject was received by the pin photo diode. A triangulation was thereby created in the same way as with an optical coincidence rangefinder. The lens draw is adjusted automatically to match the subject distance for focusing. The near-infrared beam also enabled focusing under low-light conditions, making the camera a hit product. The name "Autoboy" became synonymous with AF compact cameras.