Fully automatic energy efficient lighting control and method of making same

Abstract

A fully automatic and energy efficient lighting control or light switch comprises different settings, preset by a user, and activates all or a portion of at least one bank of lights upon detecting occupants within a room. In one embodiment, the light switch detects doppler-shifted, reflected ultrasonic waves caused by occupant motion within the room. In an automatic mode, the light switch is configured to automatically switch from an initial sensitivity level for detecting motion within a short range therefrom, to a higher sensitivity level for detecting motion anywhere within the room. After the room is empty or no motion is sensed, the light switch is configured to turn the lights off following a variable time delay. The light switch returns to its initial low sensitivity level following a predetermined grace period which begins once the lights are turned off. The lights can be turned off manually when the light switch is in its automatic mode, in which case, the light switch continues to operate at the higher sensitivity level. When motion is no longer detected, and following the variable time delay and predetermined grace period, the switch automatically returns to an automatic "on" state. In an alternative manual mode, the light switch can be activated manually and deactivated both manually and automatically. In its manual mode, the light switch is configured to deactivate the lights upon sensing no motion and is configured to reactivate the lights automatically within the predetermined grace period upon sensing motion.

Description

FIELD OF THE INVENTIONThe present invention relates generally to lighting controls. More specifically, the present invention relates to a lighting control or light switch which is automatic and energy efficient and provides automatic control of at least one bank of lights within a room, for example by detecting doppler-shifted, ultrasonic waves reflected by persons entering into and moving within the room.BACKGROUND OF THE INVENTIONConservation of energy is a critical national and worldwide concern. Continuous lighting in empty rooms is an unnecessary waste of energy. Some state and local energy conservation / building codes require installation of two light switches in the construction or reconstruction of offices, each to control a different portion of the overhead lighting. The reasoning behind such requirements is that in the interest of energy conservation, employees and janitorial personnel may be offered the opportunity to use approximately one half of the light they would norm...

AI Technical Summary

Benefits of technology

In one aspect of the invention, the light switch in an automatic mode is configured to automatically activate lights upon detecting motion of any type within a room. In accordance with this aspect, in an exemplary embodiment, the light switch is set to an initial sensitivity level so that only motion within a short range (also referred to as an initial detection range) from the light switch is detected. An ultrasonic transmitter transmits acoustic energy or an ultrasonic wave of predetermined frequency into the room and an ultrasonic receiver receives a doppler-shifted, ultrasonic reflected wave indicating motion within the room.

Once the light switch detects motion within the short range, it automatically adjusts to a higher sensitivity level so that it is able to detect motion anywhere within the room. After motion is no longer detected during a variable time delay, the light switch automatically turns the lights off and initiates a predetermined grace period during which the light switch maintains the higher sensitivity level and continues to detect motion anywhere within the room. If no motion is detected during the predetermined grace period, the light switch returns to its initial sensitivity, thereby reducing the detection range in order to detect only persons entering the room.

In the event the lights are turned off inadvertently, such as if a person remains motionless during the entire variable time delay period, the predetermined grace period advantageously allows an occupant to wave an arm or otherwise make simple motions anywhere within the room to turn the lights back on.

In another aspect of the invention, the lighting can be turned off manually while the light switch is in its automatic mode, in which case it remains at its high sensitivity level while there are occupants in the room. After no motion is detected during the variable time delay and the predetermined grace period, the automatic light switch resets to its "automatic on" state and returns to its initial sensitivity level.

Problems solved by technology

Continuous lighting in empty rooms is an unnecessary waste of energy.

Conventional manual switches are inefficient because they depend upon human judgment to turn all or only a portion of the lights on and off.

Existing automatic wall switches have also proven to be inefficient.

Because the preset sensitivity level for the reflected ultrasonic wave is fixed, a wall switch located adjacent an open door can detect persons moving outside the door and unnecessarily turn on the lights within the room.

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