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US 8,363,279 B2Granted
Method and device for setting multiple tones in halftone process to prevent mixing of adjacent ink dots
AssigneeRicoh Company, Ltd.
InventorsNaoki Kikuchi, Takashi Kimura, Takahiro Ike
Life of this patent
Estimating the term…
Abstract
A disclosed method for setting multiple tones in a halftone process upon recording an image using ink includes the steps of: dividing the image into plural dot areas; and setting the multiple tones such that at least one dot area to which the ink is not attached is present between dot areas to which the ink is attached.
Claims17
A method, performed by an image recording apparatus, for setting multiple tones in a halftone process upon recording an image using ink, the method comprising the steps of:
- (a) determining, by the image recording apparatus, for each of the multiple tones, a corresponding base dot pattern for the tone, the base dot pattern including plural dot areas,
- the plural dot areas including at least one non-discharged dot area between each pair of discharged dot areas along a horizontal direction, and including at least one non-discharged dot area between each pair of discharged dot areas along a vertical direction,
- each non-discharged dot area being a dot area for which the ink is not discharged as a dot, and
- each discharged dot area being a dot area for which the ink is discharged as a dot;
- (b) setting the multiple tones to respective base dot patterns, determined in (a), such that for each tone of the multiple tones, at least one non-discharged dot area is present between each pair of discharged dot areas along the horizontal direction and at least one non-discharged dot area is present between each pair of discharged dot areas along the vertical direction, in the base dot pattern set to the tone;
- (c) performing an error diffusion method to express halftones in the halftone process;
- (d) determining whether the ink is discharged as a dot on a preceding dot area, based on a threshold value;
- and
- (e) determining, in a case that it is determined in (d) that the ink is discharged as a dot on the preceding dot area, regardless of the threshold value, that the ink is not discharged as a dot on a current dot area.
6 more elements
An image recording apparatus for recording an image using ink, the image recording apparatus comprising:
- a head including at least one nozzle for discharging the ink;
- a setting device for setting multiple tones in a halftone process, said setting device determining, by the image recording apparatus, for each of the multiple tones, a corresponding base dot pattern for the tone, the base dot pattern including plural dot areas, the plural dot areas including at least one non-discharged dot area between each pair of discharged dot areas along a horizontal direction, and including at least one non-discharged dot area between each pair of discharged dot areas along a vertical direction, each non-discharged dot area being a dot area for which the ink is not discharged as a dot, and each discharged dot area being a dot area for which the ink is discharged as a dot, and
- said setting device setting the multiple tones to respective base dot patterns, such that for each tone of the multiple tones, at least one non-discharged dot area is present between each pair of discharged dot areas along the horizontal direction and at least one non-discharged dot area is present between each pair of discharged dot areas along the vertical direction, in the base dot pattern set to the tone;
- and
- a control device for controlling the head in accordance with the base dot patterns determined in the setting device,
- wherein the setting device performs an error diffusion method to express halftones in the halftone process, and the control device determines whether the ink is discharged as a dot on a preceding dot area, based on a threshold value, and when the control device determines that the ink is discharged as a dot on the preceding dot area, the control device determines, regardless of the threshold value, that the ink is not discharged as a dot on a current dot area.
3 more elements
A non-transitory computer-readable recording medium storing a computer-readable program used in an image recording apparatus for recording an image using ink which, when executed by a computer for controlling the image recording apparatus, causes the computer to perform a method for setting multiple tones in a halftone process, said method comprising:
- (a) determining, by the image recording apparatus, for each of the multiple tones, a corresponding base dot pattern for the tone, the base dot pattern including plural dot areas,
- the plural dot areas including at least one non-discharged dot area between each pair of discharged dot areas along a horizontal direction, and including at least one non-discharged dot area between each pair of discharged dot areas along a vertical direction,
- each non-discharged dot area being a dot area for which the ink is not discharged as a dot, and
- each discharged dot area being a dot area for which the ink is discharged as a dot;
- and
- (b) setting the multiple tones to respective base dot patterns, determined in (a), such that for each tone of the multiple tones, at least one non-discharged dot area is present between each pair of discharged dot areas along the horizontal direction and at least one non-discharged dot area is present between each pair of discharged dot areas along the vertical direction, in the base dot pattern set to the tone;
- (c) performing an error diffusion method to express halftones in the halftone process;
- (d) determining whether the ink is discharged as a dot on a preceding dot area, based on a threshold value;
- and
- (e) determining, in a case that it is determined in (d) that the ink is discharged as a dot on the preceding dot area, regardless of the threshold value, that the ink is not discharged as a dot on a current dot area.
7 more elements
Dependencies are inferred from the claim text.