Patent ID: 11947311
Assignee: BROTHER KOGYO KABUSHIKI KAISHA
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An image forming apparatus, comprising:
a main body housing including an air outlet opening;
a photosensitive drum;
a fuser configured to thermally fix toner transferred from the photosensitive drum to a sheet on the sheet;
a fan configured to generate an airflow toward the air outlet opening; and
a controller configured to, in a continuous stage of printing continuous from a beginning stage:
count a cumulative printed page number being a cumulative number of pages printed by the image forming apparatus,
in a case where the cumulative printed page number is smaller than a first page number, control the fan to rotate at a first speed, and
in a case where the cumulative printed page number is equal to or larger than the first page number, control the fan to rotate at a second speed, the second speed being higher than the first speed,

wherein the air outlet opening is located on an outer wall of the main body housing on one side in a first direction, the fan being configured to discharge air through the air outlet opening,
wherein the image forming apparatus further comprises:
a first sensor located in proximity to the outer wall of the main body housing on the one side in the first direction, the first sensor being configured to measure temperature and relative humidity; and
a second sensor located on the other side of the main body housing in the first direction, the second sensor being configured to measure temperature in a position closer than the fuser to the photosensitive drum,

wherein the controller is configured to:
process the temperature measured by the first sensor as a first atmosphere temperature, and
estimate a second atmosphere temperature being a temperature around the photosensitive drum based on the temperature measured by the second sensor.