Color office printer with a high capacity digital page image store

Claim 2

A printing apparatus using cut sheet recording media which incorporates a high capacity compressed document image storage apparatus, said printing apparatus including: an image creation system which can operate on a band by band basis; an input memory which receives and stores at least one band of an uncompressed page image, but less than 50% of an uncompressed page image from the image creation system; a page image compression system operable on images stored in said input memory on a band by band basis; a mass storage device adapted to receive and store a plurality of compressed page images from the compression system; a page image expansion system which expands compressed page image data from the mass storage device to form an expanded page image at a rate which is within 20% of a page printing rate when measured over the duration of a page printing time; an output memory which receives and stores at least one band of said expanded page image from the expansion system, but less than 50% of said expanded page image; and an apparatus which provides page image data from said output memory to a printing device wherein time taken to provide a band of image data to the printing device does not vary by more than ±50% of mean time to provide a band of image data to the printing device, said printing device having a print head comprising: (a) a plurality of drop-emitter nozzles; (b) a body of ink associated with said nozzles; (c) a pressurizing device adapted to subject ink in said body of ink to a pressure of at least 2% above ambient pressure, at least during drop selection and separation to form a meniscus with an air/ink interface; (d) drop selection apparatus operable upon the air/ink interface to select predetermined nozzles and to generate a difference in meniscus position between ink in selected and non-selected nozzles; and (e) drop separation apparatus adapted to cause ink from selected nozzles to separate as drops from the body of ink, while allowing ink to be retained in non-selected nozzles.

Claim 3

A printing apparatus using cut sheet recording media which incorporates a high capacity compressed document image storage apparatus, said printing apparatus including: an image creation system which can operate on a band by band basis; an input memory which receives and stores at least one band of an uncompressed page image, but less than 50% of an uncompressed page image from the image creation system; a page image compression system operable on images stored in said input memory on a band by band basis; a mass storage device adapted to receive and store a plurality of compressed page images from the compression system; a page image expansion system which expands compressed page image data from the mass storage device to form an expanded page image at a rate which is within 20% of a page printing rate when measured over the duration of a page printing time; an output memory which receives and stores at least one band of said expanded page image from the expansion system, but less than 50% of said expanded page image; and an apparatus which provides page image data from said output memory to a printing device wherein time taken to provide a band of image data to the printing device does not vary by more than ±50% of mean time to provide a band of image data to the printing device, said printing device having a print head comprising: (a) a plurality of drop-emitter nozzles; (b) a body of ink associated with said nozzles, said body of ink forming a meniscus with an air/ink interface at each nozzle; (c) drop selection apparatus operable upon the air/ink interface to select predetermined nozzles and to generate a difference in meniscus position between ink in selected and non-selected nozzles; and (d) drop separation apparatus adapted to cause ink from selected nozzles to separate as drops from the body of ink, while allowing ink to be retained in non-selected nozzles, said drop selection apparatus being capable of producing said difference in meniscus position in the absence of said drop separation apparatus.

Claim 4

A printing apparatus using cut sheet recording media which incorporates a high capacity compressed document image storage apparatus, said printing apparatus including: an image creation system which can operate on a band by band basis; an input memory which receives and stores at least one band of an uncompressed page image, but less than 50% of an uncompressed page image from the image creation system; a page image compression system operable on images stored in said input memory on a band by band basis; a mass storage device adapted to receive and store a plurality of compressed page images from the compression system; a page image expansion system which expands compressed page image data from the mass storage device to form an expanded page image at a rate which is within 20% of a page printing rate when measured over the duration of a page printing time; an output memory which receives and stores at least one band of said expanded page image from the expansion system, but less than 50% of said expanded page image; and an apparatus which provides page image data from said output memory to a printing device wherein time taken to provide a band of image data to the printing device does not vary by more than ±50% of mean time to provide a band of image data to the printing device, said printing device having a print head comprising: (a) a plurality of drop-emitter nozzles; (b) a body of ink associated with said nozzles, said body of ink forming a meniscus with an air/ink interface at each nozzle; (c) drop selection apparatus operable upon the air/ink interface to select predetermined nozzles and to generate a difference in meniscus position between ink in selected and non-selected nozzles; and (d) drop separation apparatus adapted to cause ink from selected nozzles to separate as drops from the body of ink, while allowing ink to be retained in non-selected nozzles, said drop selection apparatus being capable of producing said difference in meniscus position in the absence of said drop separation apparatus.

Claim 5

A printing apparatus using cut sheet recording media which incorporates a high capacity compressed document image storage apparatus, said printing apparatus including: an image creation system which can operate on a band by band basis; an input memory which receives and stores at least one band of an uncompressed page image, but less than 50% of an uncompressed page image from the image creation system; a page image compression system operable on images stored in said input memory on a band by band basis; a mass storage device adapted to receive and store a plurality of compressed page images from the compression system; a page image expansion system which expands compressed page image data from the mass storage device to form an expanded page image at a rate which is within 20% of a page printing rate when measured over the duration of a page printing time; an output memory which receives and stores at least one band of said expanded page image from the expansion system, but less than 50% of said expanded page image; and an apparatus which provides page image data from said output memory to a printing device wherein time taken to provide a band of image data to the printing device does not vary by more than ±50% of mean time to provide a band of image data to the printing device, said printing device having a print head comprising: (a) a plurality of drop-emitter nozzles; (b) a body of ink associated with said nozzles, said body of ink forming a meniscus with an air/ink interface at each nozzle and said ink exhibiting a surface tension decrease of at least 10 mN/m over a 30° C. temperature range; (c) drop selection apparatus operable upon the air/ink interface to select predetermined nozzles and to generate a difference in meniscus position between ink in selected and non-selected nozzles; and (d) drop separation apparatus adapted to cause ink from selected nozzles to separate as drops from the body of ink, while allowing ink to be retained in non-selected nozzles.

Claim 6

A printing apparatus using cut sheet recording media which incorporates a high capacity compressed document image storage apparatus, said printing apparatus including: an image creation system which can operate on a band by band basis; an input memory which receives and stores at least one band of an uncompressed page image, but less than 50% of an uncompressed page image from the image creation system; a page image compression system operable on images stored in said input memory on a band by band basis; a mass storage device adapted to receive and store a plurality of compressed page images from the compression system; a page image expansion system which expands compressed page image data from the mass storage device to form an expanded page image at a rate which is within 20% of a page printing rate when measured over the duration of a page printing time; an output memory which receives and stores at least one band of said expanded page image from the expansion system, but less than 50% of said expanded page image; and an apparatus which provides page image data from said output memory to a printing device wherein time taken to provide a band of image data to the printing device does not vary by more than ±50% of mean time to provide a band of image data to the printing device, said printing device having a print head comprising: (a) a plurality of drop-emitter nozzles; (b) a body of ink associated with said nozzles, said body of ink forming a meniscus with an air/ink interface at each nozzle and said ink exhibiting a surface tension decrease of at least 10 mN/m over a 30° C. temperature range; (c) drop selection apparatus operable upon the air/ink interface to select predetermined nozzles and to generate a difference in meniscus position between ink in selected and non-selected nozzles; and (d) drop separation apparatus adapted to cause ink from selected nozzles to separate as drops from the body of ink, while allowing ink to be retained in non-selected nozzles.