Led arrangement and method for ambient-light-dependent brightness control of leds

Abstract

An LED arrangement comprising at least one LED, which receives an LED illumination voltage in accordance with a square-wave signal, wherein the brightness of the LED is dependent on the ambient luminosity, which is measured by means of the LED, which is switched in a non-illuminated state as a light sensor. The at least one LED is arranged together with a first and a second transistor in a bridge circuit such that the first transistor applies the LED illumination voltage to the LED in accordance with the square-wave signal, and the second transistor applies a voltage having inverted polarity as the LED illumination voltage to the LED in intervals of the turned-off times of the LED, wherein the duty cycle of the square-wave signal is dependent on the strength of a photocurrent, which flows through the LED when the voltage having inverted polarity is applied thereto.

Dependencies are inferred from the claim text.