Image forming apparatus and control method therefor
AssigneeCanon Kabushiki Kaisha
InventorKeigo Ogura
Life of this patent
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Abstract
An image forming apparatus includes DMA control units each of which is provided with DMA controllers. Each DMA controller is provided with a plurality of data buffers respectively corresponding to different addresses in a subscanning direction. Each of a predetermined number of pixel data in a main scanning direction is stored in an associated one of the data buffers. Pixel data stored in each of the data buffers are output to an image memory based on the address in the subscanning direction, which corresponds to the associated data buffer.
Claims8
An image forming apparatus having an exposure unit configured to scan an image carrier in a main scanning direction with irradiation light modulated based on image data, comprising:
- an input unit configured to input image data in units of lines;
- a storage unit configured to store the image data input by the input unit;
- a plurality of data retention units configured to respectively correspond to different addresses in a subscanning direction of the storage unit;
- a writing unit configured to write pixel data constituting the image data input in the units of lines to the plurality of data retention units based on curve information for correcting a curve of a scanning line of the irradiation light falling on the image carrier;
- a control unit configured to control, when the writing unit writes a predetermined number of pixel data to a specific one of the plurality of data retention units, the specific one of the plurality of data retention units to store the predetermined number of pixel data to an address in the subscanning direction, which corresponds to the specific one of the plurality of data retention units, in the storage unit;
- and
- a transfer unit configured to read the image data stored in the storage unit in units of lines while changing the address in the main scanning direction without changing the address in the subscanning direction, and to transfer the read image data to the exposure unit.
An image forming apparatus having an exposure unit configured to scan an image carrier in a main scanning direction with irradiation light modulated based on image data, comprising:
- an input unit configured to input image data;
- a storage unit configured to store the image data input by the input unit;
- a plurality of data retention units configured to respectively correspond to different addresses in a subscanning direction of the storage unit;
- a reading unit configured to read the image data which is input in the units of lines to the plurality of data retention units and stored in the storage unit, to a specific one of the plurality of data retention units, which corresponds to an address in the subscanning direction of the image data, based on curve information for correcting a curve of a scanning line of the irradiation light falling on the image carrier;
- a control unit configured to control, when the writing unit writes a predetermined number of pixel data to a specific one of the plurality of data retention units, the specific one of the plurality of data retention units to output the predetermined number of pixel data;
- and
- a transfer unit configured to transfer the image data read from the specific one of the plurality of data retention units by the control unit, to the exposure unit.
A control method for an image forming apparatus having an exposure unit configured to scan an image carrier in a main scanning direction with irradiation light modulated based on image data, comprising:
- inputting image data in units of lines;
- storing the input image data input in a storage unit;
- writing pixel data constituting the image data input in the units of lines to one of a plurality of data retention units configured to respectively correspond to different addresses in a subscanning direction of the storage unit based on curve information for correcting a curve of a scanning line of the irradiation light falling on the image carrier;
- performing control, when a predetermined number of pixel data is written to a specific one of the plurality of data retention units, of the specific one of the plurality of data retention units to store the predetermined number of pixel data to an address in the subscanning direction, which corresponds to the specific one of the plurality of data retention units in the storage unit;
- and
- reading the image data stored in the storage unit while changing the address in the main scanning direction without changing the address in the subscanning direction, and transferring the read image data to the exposure unit.
A control method for an image forming apparatus having an exposure unit configured to scan an image carrier in a main scanning direction with irradiation light modulated based on image data, comprising:
- inputting image data;
- storing the image data in a storage unit;
- reading the image data, which is input in the units of lines to the plurality of data retention units and stored in the storage unit, to one data retention unit, which corresponds to an address in the subscanning direction of the image data, among a plurality of data retention units respectively corresponding to different addresses in the subscanning direction of the storage unit, based on curve information for correcting a curve of a scanning line of the irradiation light falling on the image carrier;
- controlling, when the writing unit writes a predetermined number of pixel data to a specific one of the plurality of data retention units, the specific one of the plurality of data retention units to output the predetermined number of pixel data;
- and
- transferring the image data output from the specific one of the plurality of data retention units to the exposure unit.
Dependencies are inferred from the claim text.