System for controlling light in dependence of time-of-flight signal

• US 8,212,500 B2
• Filed: 10/26/2007
• Issued: 07/03/2012
• Est. Priority Date: 10/26/2007
• Status: Expired due to Fees

• Current Assignee: Lite-On Technology Corporation
• Original Assignee: Lite-On It Corporation (Lite-On Technology Corporation)
• Inventors: Van Endert, Tony Petrus
• Primary Examiner(s): TRAN, THUY V
• Application Number:
  US12/739,772
• Publication Number:
  US 20100253241A1
• Time in Patent Office: 1,712 Days
• Field of Search: 315/246, 315/267, 315/291, 315/308, 315/360, 700/306
• US Class Current: 315/360
• CPC Class Codes: H03K 17/94 characterised by the way in which the control signals are generated
• CPC Class Codes: H03K 2217/94005 activated by voice or sound
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 47/125 by using cameras
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

A lighting system comprising a lamp comprising an array of LEDs arranged to transform electricity into a light beam having properties including intensity, color, color temperature; a fight control system comprising a LED driver and a pulse width modulator arranged to adjust said light beam properties; a DA-converter, an ultrasound driver and an ultrasonic transmitter arranged to convert a digital transmit signal into the transmission of an ultrasonic pulse; an ultrasonic receiver and an amplifier arranged to receive reflected ultrasonic signals and transform said ultrasonic signal in a voltage, and a comparator arranged to generate a digital receive signal if said voltage is greater than a predetermined threshold; a processing system arranged to derive a time-of-flight signal representing the time differences between said digital transmit and receive signals and to send control signals to said light control system in dependence of said time-of-flight signal.

Claims

1. A lighting system comprising:

a lamp comprising an array of LEDs arranged to transform electricity into a light beam having properties including intensity, colour, colour temperature;

a light control system comprising a LED driver and a pulse width modulator arranged to adjust said light beam properties;

a DA-converter, an ultrasound driver and an ultrasonic transmitter arranged to convert a digital transmit signal into the transmission of an ultrasonic pulse;

an ultrasonic receiver and an amplifier arranged to receive reflected ultrasonic signals and transform said ultrasonic signal in a voltage, and a comparator arranged to generate a digital receive signal if said voltage is greater than a predetermined threshold;

a processing system arranged to derive a time-of-flight signal representing the time differences between said digital transmit and receive signals and to send control signals to said light control system in dependence of said time-of-flight signal,

wherein said processing system, said pulse width modulator, said DA-converter and said comparator are integrated in a single microcontroller chip.

2. The lighting system of claim 1, wherein said microcontroller chip is chosen from the single-chip 8-bit 8051/80C51 microcontroller family.

3. The lighting system of claim 2, wherein said microcontroller chip comprises fewer than 4 kB ROM and fewer than 512 B RAM.

4. The lighting system of claim 1, wherein said ultrasonic transmitter and said ultrasonic receiver are integrated in a piezoelectric ultrasound transducer.

5. The lighting system of claim 1, wherein said transmitting ultrasound driver and said amplifier are integrated in a pre-processing circuit.

6. The lighting system of claim 5, wherein said pre-processing circuit further comprises a second order filter for filtering out low frequent signals from said received signal.