Circuit arrangement and actuation method for semi-conductor light sources

Abstract

The invention relates to a circuit arrangement and a actuation method for actuating semi-conductor light sources, comprising video electronics producing a timing signal (int Strobe) and an image valuetable, a driver circuit made of a digital (1) and an analog (3, 7) part, and a semi-conductor light source module (5), which may comprise one or more semi-conductor light sources, wherein between thedriver circuit and the semi-conductor light source module a switch (S1, S2,...) is disposed, which is actuated by the driver circuit and which can switch the signal controlling the target brightnessof the semi-conductor light source module to ground after the digital-to-analog converter (7) processing. The use of the switch enables the production of very short light pulses, the minimum pulse duration of which is independent of the delay time of the digital-to-analog converter.

Description

technical field [0001] The invention relates to projection devices equipped with semiconductor light sources. In particular microdisplay applications for front and rear projection are mentioned here. Background technique [0002] High-power semiconductor light sources such as high-power light-emitting diodes have recently been increasingly used in applications currently reserved for high-pressure discharge lamps. Precisely in the field of projection, semiconductor light sources are not driven continuously but pulsed in order to meet the requirements there. In this case, very short pulses are used, which have a very high power density for this purpose. [0003] In display applications, multiple colors are used, usually at least 3 colors. The driver circuit is divided into video electronics, which process the input signal, and drive electronics, which are usually divided into a digital part and an analog part, which are connected via a digital / analog converter. The video e...

AI Technical Summary

Problems solved by technology

However, this is problematic when switching off, since the minimum on-duration depends on the processing speed of the drive electronics

For this reason, the drive electronics must have fast logic circuits and fast analog / digital converters, since otherwise the drive electronics cannot achieve the required processing speed

However, fast analog-to-digital converters and fast logic circuits (such as high-speed clocked microcontrollers) are very expensive, which has an adverse effect on the pricing of the final product)

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