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US 5,311,256 AGranted
Image forming apparatus maintaining image density stability against humidity
AssigneeMinolta Camera Kabushiki Kaisha
InventorsSuguru Hamamichi, Yoshihiro Hattori, Yoshinobu Hada
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Abstract
An image forming apparatus having a toner density detecting sensor, a humidity sensor and a memory for storing past record of detected humidity. The toner density is compensated by referring to the detected toner density, currently detected humidity and past record of humidity to maintain image density stability.
Claims23
An image forming apparatus comprising:
- an image forming means for forming images by use of an electrophotographic process, said image forming means including a developing means for developing electrostatic latent images on a photosensitive medium by a developer which comprises toner and carrier;
- toner density detecting means for detecting toner density of the developer;
- humidity detecting means, provided near the developing means, for detecting humidity adjacent the developing means;
- means for storing a past record of humidity detected within a set predetermined time period;
- means for storing a series of values of toner density relative to humidity, each series of values being representative of a different toner density value for the same humidity;
- and
- means for controlling the image forming means in correlation with detected toner density and the stored past record of humidity so as to maintain image density stability, including selecting one of the series of values to correct the toner density.
4 more elements
An image forming apparatus comprising:
- an image forming means for forming toner images on a photosensitive medium, said image forming means including a developing means for developing electrostatic latent images on the photosensitive medium by a developer which comprises toner and carrier, including a housing for storing the developer;
- toner density detecting means for detecting toner density of the developer;
- humidity detecting means, provided within the developer housing for detecting humidity adjacent the developing means;
- means for storing a series of values of toner density relative to humidity, each series of values being representative of a different toner density value for the same humidity;
- means for storing a past record of humidity detected within a set predetermined time period;
- and
- means for controlling the image forming means by referring to the detected toner density, the stored past record of humidity, and a currently detected humidity so as to maintain image density stability, including selecting one of the series of values to correct the toner density.
4 more elements
An image forming apparatus comprising:
- an image forming means for forming images by use of an electrophotographic process, said image forming means including a developing means for developing electrostatic latent images on a photosensitive medium by a developer which comprises toner and carrier;
- toner density detecting means for detecting toner density of the developer;
- humidity detecting means for detecting humidity adjacent the developing means;
- means for periodically storing a detected humidity and maintaining it for a predetermined time period regardless of any operation of the image forming means;
- means for periodically discarding a stored detected humidity regardless of any operation of the image forming means, and
- means for controlling the image forming means in correlation with detected toner density, a presently-stored detected humidity, a detected current humidity, and a stored table of correction values corresponding to a toner density value relative to humidity for various humidity states.
3 more elements
An electrophotographic image forming apparatus comprising:
- an image forming means for forming images by use of an electrophotographic process, said image forming means including a developing means for developing electrostatic latent images on a photosensitive medium by a developer which comprises toner and carrier;
- toner density detecting means for detecting a toner density of the developer;
- humidity detecting means, provided near the developing means, for detecting humidity adjacent the developing means;
- means for storing a plurality of previously-detected humidity values detected within a set predetermined time period;
- and
- means for controlling the image forming means in correlation with detected toner density and the plurality of previously-detected humidity values so as to maintain the image density stable.
3 more elements
An electrophotographic image forming apparatus comprising:
- an image forming means for forming toner images on a photosensitive medium, said image forming means including a developing means for developing electrostatic latent images on the photosensitive medium by a developer which comprises toner and carrier;
- toner density detecting means for detecting toner density of the developer;
- humidity detecting means, provided near the developing means, for detecting humidity adjacent the developing means;
- means for storing a past record of humidity detected within a set predetermined time period;
- and
- means for controlling the image forming means by referring to the detected toner density, the stored past record of humidity, and a currently detected humidity so as to maintain image density stability.
3 more elements
An electrophotographic image forming apparatus comprising:
- an image forming means for forming images by use of an electrophotographic process, said image forming means including a developing means for developing electrostatic latent images on a photosensitive medium by a developer which comprises toner and carrier;
- toner density detecting means for detecting toner density of the developer;
- humidity detecting means for detecting humidity adjacent the developing means;
- means for periodically storing a detected humidity and maintaining it for a predetermined time period regardless of any operation of the image forming means;
- means for periodically discarding a stored detected humidity regardless of any operation of the image forming means;
- and
- means for controlling the image forming means in correlation with detected toner density, a presently-stored detected humidity, and a detected current humidity.
4 more elements
Dependencies are inferred from the claim text.