Abstract: The present invention relates to a device and a method for monitoring a thread wound on a bobbin during operation in a sewing machine that reduces the expenditure on apparatus and production technology with increased monitoring reliability wherein at least three different marking states are provided in the area of the bobbin (3) and are coupled to an optical device (8) in such a manner that movement of the bobbin (3) produces a change in marking which can be detected in the optical device (8) which can be evaluated in a logic unit connected to the optical device (8), that the marking (10) in the area of the bobbin (3) comprises more than two states, wherein at least one state is defined by at least one true color (g, r, b) or a mixture of the primary colors.

Abstract: The present invention relates to a device and a method for monitoring a thread wound on a bobbin during operation in a sewing machine. In order to further develop a method and a device of the type specified initially whilst reducing the expenditure on apparatus and production technology with increased monitoring reliability it is suggested for a device for monitoring a thread wound on a bobbin (3) during operation in a sewing machine (1), wherein at least two different marking states are provided in the area of the bobbin (3) and are coupled to an optical device (8) in such a manner that movement of the bobbin (3) produces a change in marking which can be detected in the optical device (8) which can be evaluated in a logic unit connected to the optical device (8), that the marking (10) in the area of the bobbin (3) comprises more than two states, wherein at least one state is defined by at least one color (g, r, b) or a mixture of the primary colors.