Belt media drive for printer with dual belt encoders

An encoding system for a media handling system including an endless belt fabricated with a belt seam for transporting media along a media path, comprising:

• encoding indicia defined on or in the endless belt and comprising a sequence of indicia with an encoder pitch spacing;
• a first encoder transducer responsive to the encoding indicia to provide a first encoder signal;
• a second encoder transducer responsive to the encoding indicia to provide a second encoder signal;
• said second encoder transducer spatially separated from the first encoder transducer such that the sequence of indicia successively pass the respective first and second transducers as the belt is moved to handle media;
• and
• an encoder processor responsive to the first and second encoder signals to determine position data regarding the endless belt, wherein the processor is responsive to said second encoder signal to determine a belt position until the seam passes between the first and second encoder transducers, and the processor is responsive to said first encoder signal to determine the belt position until after the seam passes the second encoder transducer, wherein the processor is responsive to the second transducer to determine the belt position.

An encoding system for a media handling system including an endless belt fabricated with a belt seam for transporting media along a media path, comprising:

• encoding indicia defined on or in the endless belt and comprising a sequence of indicia with an encoder pitch spacing, the belt seam generally transverse to a direct of movement of the sequence of indicia as the belt is moved, the encoding indicia further including an index indicia marking a position of the seam;
• a first encoder transducer responsive to the encoding indicia to provide a first encoder signal;
• a second encoder transducer responsive to the encoding indicia to provide a second encoder signal;
• said second encoder transducer spatially separated from the first encoder transducer such that the sequence of indicia successively pass the respective first and second transducers as the belt is moved to handle media;
• a seam detecting apparatus to detect an index indicia associated with the belt and generate a index signal;
• and
• an encoder processor responsive to the first and second encoder signals and the index signal to determine position data regarding the endless belt, said processor responsive to detection of the index indicia to transfer between use of said first encoder signal and said second encoder signal in the determination of a belt position.

An encoding system for a media handling system including an endless belt fabricated with a belt seam, comprising:

• encoding indicia defined on or in the endless belt and comprising a sequence of indicia with an encoder pitch spacing;
• a first encoder transducer responsive to the encoding indicia to provide a first encoder signal;
• a second encoder transducer responsive to the encoding indicia to provide a second encoder signal;
• said second encoder transducer spatially separated from the first encoder transducer such that the sequence of indicia successively pass the respective first and second transducers as the belt is moved to handle media;
• and
• an encoder processor responsive to the first and second encoder signals to determine position data regarding the endless belt and to phase differences between said first encoder signal and said second encoder signal to compensate for variations in the encoder pitch spacing caused by belt temperature differentials.

A method for providing belt position information for a media handling system including an endless belt fabricated with a belt seam for transporting media along a media path and having encoder indicia with an encoder pitch spacing defined on or in the belt, comprising:

• moving the endless belt;
• reading a first encoder signal from a first encoder transducer responsive to the encoding indicia;
• reading a second encoder signal from a second encoder transducer responsive to the encoding indicia, said second encoder transducer spatially separated from the first encoder transducer;
• and
• processing the first encoder signal and the second encoder signal to determine position data regarding the endless belt, including transferring between use of the first encoder signal and use of the second encoder signal to calculate a belt position in dependence on position of the seam relative to the first and second encoder transducers.

A method for providing belt position information for a media handling system including an endless belt for transporting media along a media path, the belt fabricated with a belt seam and having encoder indicia with an encoder pitch spacing defined in or on the belt, the belt further having an index indicia marking a position of the belt, comprising:

• reading a first encoder signal from a first encoder transducer responsive to the encoding indicia;
• reading a second encoder signal from a second encoder transducer responsive to the encoding indicia, said second encoder transducer spatially separated from the first encoder transducer;
• detecting the index indicia;
• processing the first encoder signal and the second encoder signal to determine position data regarding the endless belt, including transferring between use of the first encoder signal and use of the second encoder signal to calculate a belt position in dependence on detecting the index indicia indicating position of the seam relative to the first and second encoder transducers.

A method for providing belt position information for a media handling system including an endless belt for transporting media along a media path, the belt having encoder indicia with an encoder pitch spacing defined in or on the belt, comprising:

• reading a first encoder signal from a first encoder transducer responsive to the encoding indicia;
• reading a second encoder signal from a second encoder transducer responsive to the encoding indicia, said second encoder transducer spatially separated from the first encoder transducer;
• processing the first encoder signal and the second encoder signal to determine position data regarding the endless belt;
• compensating the pitch spacing for variations caused by belt dimensional variations, using said first encoder signal and said second encoder signal.

A media handling system, comprising:

• an endless belt fabricated with a belt seam for transporting media along a media path;
• encoding indicia defined on or in the endless belt and comprising a sequence of indicia with an encoder pitch spacing;
• a first encoder transducer responsive to the encoding indicia to provide a first encoder signal;
• a second encoder transducer responsive to the encoding indicia to provide a second encoder signal;
• said second encoder transducer spatially separated from the first encoder transducer such that the sequence of indicia successively pass the respective first and second transducers as the belt is moved to handle media;
• and
• an encoder processor responsive to the first and second encoder signals to determine position data regarding the endless belt, said processor adapted to transfer between use of said first encoder signal and use of said second encoder signal to determine a belt position in dependence on a position of the seam relative to the first and second encoder transducers.