Image forming apparatus
AssigneesKabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
InventorKoji Imamiya
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Abstract
The image forming apparatus of the present embodiment has two limiters composed of a conventional high order limiter and a low order limiter, and carries out control to switch the limiter according to a temperature and a humidity so as not to reach a image contrast potential equal to or greater than those limiters. Carrier development can occur if image formation is performed in a state where the image contrast potential is high. Therefore, by providing a low order limiter as in the present embodiment and carrying out control so as not to exceed the low order limiter at the time of the image formation, an occurrence of the carrier development can be suppressed, and an image density can also be within a prescribed range.
Claims20
An image forming apparatus, comprising:
- an image forming unit comprising a developing device for developing an image with a two-component developing agent to form the image;
- a toner cartridge configured to supply toner having a glass transition temperature of about 50 degrees centigrade or lower to the developing device;
- a humidity detector configured to detect humidity of an inside or outside of the image forming apparatus;
- a temperature detector configured to detect temperature of an inside or outside of the image forming apparatus;
- and
- a controller configured to compare a temperature value detected by the temperature detector with a first temperature threshold value previously set and compare a humidity value detected by the humidity detector with a first humidity threshold value previously set;
- and switch an upper limit value of a first development condition which is one of development conditions from a first value to a second value smaller than the first value to carry out control to form the image so that the upper limit value of the first development condition is less than or equal to the second value when both the temperature value and the humidity value are greater than or equal to the threshold values thereof.
A low temperature fixing image forming apparatus, comprising:
- an image forming unit comprising a developing device for developing an image with a two-component developing agent for low temperature fixing to form the image;
- a toner cartridge configured to supply toner having a glass transition temperature of about 50 degrees centigrade or lower to the developing device;
- a humidity detector configured to detect humidity of an inside or outside of the image forming apparatus;
- a temperature detector configured to detect temperature of an inside or outside of the image forming apparatus;
- and
- a controller configured to compare a temperature value detected by the temperature detector with a first temperature threshold value previously set and compare a humidity value detected by the humidity detector with a first humidity threshold value previously set;
- and switch an upper limit value of a first development condition which is one of development conditions from a first value to a second value smaller than the first value to carry out control to form the image so that the upper limit value of the first development condition is less than or equal to the second value when both the temperature value and the humidity value are greater than or equal to the threshold values thereof.
An image forming method, comprising:
- supplying toner having a glass transition temperature of about 50 degrees centigrade or lower to a developing device in an image forming apparatus;
- detecting humidity of an inside or outside of the image forming apparatus;
- detecting temperature of an inside or outside of the image forming apparatus;
- developing an image with a two-component developing agent to form the image;
- comparing a temperature value detected with a first temperature threshold value previously set and comparing a humidity value detected with a first humidity threshold value previously set;
- and
- switching an upper limit value of a first development condition which is one of development conditions from a first value to a second value smaller than the first value to carry out control to form the image so that the upper limit value of the first development condition is less than or equal to the second value when both the temperature value and the humidity value are greater than or equal to the threshold values thereof.
Dependencies are inferred from the claim text.