LLK 3 - A New Sound Camera Based on Laser Beam Exposure

In order to avoid the disadvantages of existing light valve cameras the new laser beam camera LLK 3 has been designed for recording of analogue tracks with high quality and long time stability. A newly designed drive control system with stepper motor enables bi-phase master and slave operation. In addition it offers the fast and easy implementation of already existing digital recording systems like DOLBY SR-D or DTS. The sound drum of the camera is fitted with a high definition incremental tacho unit which is used for synchronizing the laser beam scanner and the DSP system. The DSP unit takes care of the audio processing and switches the laser beam on and off by means of an acousto-optical deflector. The deflection system works completely without mechanically moved elements, therefore no mechanical resonance has an impact on the frequency response. All important adjustments like track position, exposure intensity, frequency response etc. can be programmed by means of a microcontroller. As the He-Ne Laser is operated at a low intensity level the long term stability and reliability is evident. A sophisticated monitoring system offers unique features such as simultaneous reproduction of the audio signal derived directly from the laser beam via a beam splitter. An ocular in connection with a rotating polygon mirror can be used for viewing the beam recording. Besides the two channel analogue input a digital audio input (AES/EBU-48 kHz) for direct transfer from digital systems is also available. The digital audio processing offers additional possibilities like the recording of special test and control signals or direct simultaneous recording of the DTS-Control signal, etc. The basic recorder model works without PC monitor and keyboard and is controlled only with conventional keys.

Published

1995-09

Content type

Original Research

DOI

10.5594/M00515

ISBN

978-1-61482-923-2