Integrated light emitting and light detecting device

A method of manufacturing a lighting device, comprising:

• providing a light guide having a first edge, a second edge opposite to the first edge, a planar first surface extending between the first edge and the second edge, and a planar second surface opposite to the first surface;
• disposing a first light detector along the first edge of the light guide, the first light detector coupled to the first light guide to receive light propagating therein through the first edge, the first light detector configured to produce a first signal based on an amount of light received from the light guide through the first edge;
• disposing a second light detector along the second edge of the light guide, the first light detector coupled to the first light guide to receive light propagating therein through the second edge, the second light detector configured to produce a second signal based on an amount of light received from the light guide through the second edge;
• electrically connecting the first light detector and the second light detector, the first and second light detectors being configured to produce a control signal indicating a direction of movement of an object relative to the first edge and the second edge based at least in part on the first signal and the second signal;
• forming at least one light gathering feature on at least one of the first surface and the second surface, the at least one light gathering feature configured to direct light incident on the light guide into the light guide;
• forming at least one light turning feature on at least one of the first and the second surface, the at least one light turning feature configured to direct light propagating within the light guide away from the light guide;
• and
• disposing at least one light source along one or more edges of the light guide.

A lighting device, comprising:

• means for guiding light having a first edge and a second edge opposite to the first edge;
• first means for detecting light disposed along the first edge of the means for guiding light and coupled to the first means for guiding light to receive light propagating therein, the first means for detecting light configured to produce a first signal based on an amount of light received from the first means for guiding light through the first edge;
• second means for detecting light disposed along the second edge of the means for guiding light and coupled to the first means for guiding light to receive light propagating therein, the second means for detecting light configured to produce a second signal based on an amount of light received from the first means for guiding light through the second edge;
• means for gathering light disposed on the means for guiding light, the means for gathering light configured to couple light incident on the means for guiding light into the means for guiding light;
• and
• means for detecting a direction of movement of an object relative to the first edge and the second edge based at least in part on a variation of incident light across the first means for guiding light between the first edge and the second edge, the detecting means including the first means for detecting light and the second means for detecting light and being configured to produce a control signal indicating the detected direction of movement of the object.

A method of sensing a direction of movement of an object across a lighting panel based on the variation of light incident on the lighting panel, the lighting panel having at least a first light detector coupled to a first edge of the lighting panel and a second light detector coupled to a second edge of the lighting panel, the second, edge being opposite to the first edge, the method comprising:

• at a first time,
• receiving light propagating within the lighting panel at the first detector and producing a first signal, the first signal indicating the amount of light detected by the first light detector at the first time, and
• receiving light propagating within the lighting panel at the second detector and producing a second signal, the second signal indicating the amount of light detected by the second detector at the first time;
• at a second time,
• receiving light propagating within the lighting panel at the first detector and producing a third signal, the third signal indicating the amount of light detected by the first light detector at the second time, and
• receiving light propagating within the lighting panel at the second detector and producing a fourth signal, the fourth signal indicating the amount of light detected by the second detector at the second time;
• and
• determining the direction of the movement of the object relative to the first and second edges based on the first, second, third, and fourth signals.