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US 2006/0133832 A1Published application
Image forming apparatus and image forming method
AssigneesKabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
InventorsFumiyuki Watanabe, Masayoshi Karasawa
Life of this patent
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Abstract
The attenuation characteristic of the surface potential of a photosensitive drum 20 is periodically detected. A target value −Vgt for a grid bias voltage −Vg applied to a charging unit 24, which is necessary to maintain, at a set value −Vods, the charging potential −Vod of the developing portion of the photosensitive drum 20, is derived from the detected attenuation characteristic. During image forming in which a developing unit 24 operates, the grid bias voltage −Vg of the charging unit 24 is set to the derived target value −Vgt.
Claims13
An image forming apparatus comprising:
- a generation section configured to analyze image pattern data corresponding to an image of a document to thereby generate image data Y indicating a yellow image, image data M indicating a magenta image, image data C indicating a cyan image, and image data K indicating a black image;
- a first control section configured to permit monochrome printing corresponding to the image data K when the generation section generates only the image data K;
- a determination section configured to determine whether the image data items Y, M and C each correspond to a white image, when the generation section generates the image data items Y, M, C and K;
- a second control section configured to delete the image data items Y, M and C included in the image data items Y, M, C and K generated by the generation section, and to permit monochrome printing corresponding to the remaining image data K, when a determination result of the determination section is an affirmative result;
- and
- a third control section configured to permit color printing corresponding to the image data items Y, M, C and K generated by the generation section, when the determination result of the determination section is a negative result.
3 more elements
An image forming apparatus comprising:
- a print section including an image carrier and configured to perform monochrome printing in which a black image is formed on the image carrier, using a black developer, and is then transferred to a paper sheet, the print section being also configured to perform color printing in which a yellow image, a magenta image, a cyan image and a black image are formed on the image carrier, using a yellow developer, a magenta developer, a cyan developer and a black developer, respectively, and are then transferred to a paper sheet;
- a detection section configured to detect whether each of the yellow developer, the magenta developer, the cyan developer and the black developer remains;
- a first determination section configured to determine whether printing by the print section can be continued using at least one remaining developer, when the detection section detects that at least one of the developers does not remain;
- a control section configured to cause the print section to continue printing, when a determination result of the first determination section is an affirmative result;
- and
- a control section configured to cause the print section to interrupt printing, when the determination result of the first determination section is a negative result.
3 more elements
An image forming method comprising:
- analyzing image pattern data corresponding to an image of a document to thereby generate image data Y indicating a yellow image, image data M indicating a magenta image, image data C indicating a cyan image, and image data K indicating a black image;
- permitting monochrome printing corresponding to the image data K when only the image data K is generated;
- determining whether the image data items Y, M and C each correspond to a white image, when the image data items Y, M, C and K are generated;
- deleting the image data items Y, M and C included in the generated image data items Y, M, C and K, and permitting monochrome printing corresponding to the remaining image data K, when a determination result is an affirmative result;
- and
- permitting color printing corresponding to the generated image data items Y, M, C and K, when the determination result is a negative result.
3 more elements
Dependencies are inferred from the claim text.