Patents by Inventor Heinz J. Schroder

Heinz J. Schroder has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Optical scanning arrangement for maintaining constant the light output of a laser beam or the laser current
    Patent number: 5016233
    Abstract: An optical scanning arrangement in which a laser beam is generated by a source with a monitor diode. The laser beam is focused on an optical recording medium. A summing amplifier has a first input connected to a source of a periodic signal. This source of periodic signal is also connected to a first input of a multiplier. The multiplier has an output connected to a second input of the summing amplifier. This summing amplifier has an output connected to a positioning device in the focusing circuit for the laser beam. This focusing circuit has an actual value which is supplied to a third input of the summing amplifier. The multiplier receives a laser controlling signal on a second input for the purpose of maintaining the light output of the laser beam at a constant level.
    Type: Grant
    Filed: September 28, 1988
    Date of Patent: May 14, 1991
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventors: Yasuaki Morimoto, Heinz J. Schroder, Friedhelm Zucker