Image forming apparatus and image forming method having band development scheduler for a plurality of pages
AssigneeCanon Kabushiki Kaisha
InventorShinichiro Maekawa
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Abstract
A scheduler develops a band in which a development processing time is longer than an image formation process speed so that a band development process can always be performed during a continuous image formation. To form images at a high throughput, a CPU analyzes print data from a plurality of pages, and a band development schedule is optimized when an image is formed on the basis of a band unit basis on the basis of the developing processing time which is previously predicted for the plurality of pages.
Claims12
An image forming method carried out in an image forming apparatus having a print engine for forming a plurality of pages in an image forming area based on print data received from an external apparatus, said method comprising:
- a predicting step of calculating prediction information, on a page unit basis, to predict a development processing time to develop intermediate data based on the print data received from the external apparatus to a bit map image;
- a specifying step of specifying, for all of a plurality of bands included in the plurality of pages to be formed in the image forming area, whether a band has a development processing time longer than a development processing time derived from an image forming process speed of the print engine based on the prediction information calculated in said predicting step;
- a developing step of developing bands specified in said specifying step as having a development processing time longer than the derived development processing time into a bit map image prior to issuance of a TOP signal;
- and
- a controlling step of controlling the print engine to start forming the plurality of pages after said developing step.
An image forming apparatus comprising:
- a print engine for forming a plurality of pages in an image forming area based on print data received from an external apparatus;
- a processor for calculating prediction information, on a page unit basis, to predict a development processing time to develop intermediate data based on the print data received from the external apparatus to a bit map image, and for specifying, for all of a plurality of bands included in the plurality of pages to be formed in the image forming area, whether a band has a development processing time longer than a development processing time derived from an image forming process speed of said print engine based on the calculated prediction information;
- a data generator for developing bands specified by said processor as having a development processing time longer than the derived development processing time into a bit map image prior to said print engine issuing a TOP signal;
- and
- a controller for controlling said print engine to start forming the plurality of pages after bands specified by said processor as having a development processing time longer than the derived development processing time have been developed by said data generator.
A color image forming method carried out in a color image forming apparatus having a print engine for forming a plurality of pages in an image forming area for each of a plurality of color components based on color print data received from an external apparatus, said method comprising:
- a specifying step of specifying, for all of a plurality of bands included in the plurality of pages to be formed in the image forming area, whether a band has a development processing time longer than a development processing time derived from an image forming process speed of the print engine;
- a developing step of developing bands specified in said specifying step as having a development processing time longer than the derived development processing time into a bit map image prior to issuance of a TOP signal;
- and
- a controlling step of controlling the print engine to start forming the plurality of pages for each of the plurality of color components after said developing step.
A color image forming apparatus comprising:
- a print engine for forming a plurality of pages in an image forming area for each of a plurality of color components based on color print data received from an external apparatus;
- a processor for specifying, for all of a plurality of bands included in the plurality of pages to be formed in the image forming area, whether a band has a development processing time longer than a development processing time derived from an image forming process speed of said print engine;
- a data generator for developing bands specified by said processor as having a development processing time longer than the derived development processing time into a bit map image prior to said print engine issuing a TOP signal;
- and
- a controller for controlling said print engine to start forming the plurality of pages for each of the plurality of color components, after said data generator develops bands specified by said processor as having a development processing time longer than the derived development processing time into a bit map image.
Dependencies are inferred from the claim text.