Image forming apparatus and method for controlling the image forming apparatus

An image forming apparatus including a polygon motor and a paper feed mechanism, the polygon motor serving to rotate a mirror for deflecting a light beam to expose an image carrier to the light beam, the paper feed mechanism conveying a sheet of paper to a position at which an image developed on the image carrier is transferred, the apparatus comprising:

• a temperature sensor that detects an operating ambient temperature of the polygon motor;
• and
• a controller that controls the polygon motor and the paper feed mechanism depending on a temperature detected by the temperature sensor;
• wherein
• if the temperature detected by the temperature sensor is equal to or greater than a preset temperature, the controller controls, before operation for giving a command to start image formation is performed, the polygon motor to rotate at a speed lower than a rated speed that is a rotational speed for latent image formation;
• increases, in response to the operation, a rotational speed of the polygon motor up to the rated speed;
• and controls the paper feed mechanism to start conveying a sheet of paper at a time when a period of time variable depending on the detected temperature has elapsed, the period of time being preset to be shorter as the detected temperature increases, in expectation of a time required for the rotational speed of the polygon motor to reach the rated speed, and
• if the detected temperature is less than the preset temperature, the controller increases, in response to the operation, the rotational speed of the polygon motor, and controls the paper feed mechanism to start conveying the sheet of paper at a time when a preset period of time has elapsed since the rotational speed of the polygon motor reached the rated speed.