Abstract: A paper feeding control method for compensating the rotational speed of a paper feeding roller by varying the rotational speed appropriately according to the paper feed delay when detecting the presence of the paper feed delay on a paper feeding path of a liquid electrophotographic color printing device. The paper feeding control method measures the time taken for a paper to be fed on the paper feeding path to a certain part of the feeding path, and determines the presence and degree of the paper delayed at the certain part by comparing the measured time at the certain part with a preset paper feeding time for the certain part. Next, according to the determination made, the method adjusts the rotational speed of the driving motor for driving the paper feeding roller to increase the rotational speed of the paper feeding roller, and to compensate for the paper feed delay.

Abstract: A color printer capable of detecting and correcting color registration error.

Abstract: An electrophotographic device and a density control method are disclosed. In the apparatus such as a color laser beam printer and a copier using an electrophotographic developing method, the invention obtains an optimum print output regardless of the remaining toner or other contamination by locating a density control module inside of a transfer body, and by providing a transparent window in a dielectric sheet formed on the exterior surface of the transfer body.

Abstract: An image forming device forms an image on a recordable medium with image data supplied from a document. The device provides an otpimum print quality by varying a fixing temperature of a fixing unit after presuming an amount of consumed toner. In another embodiment, the image forming device is capable of supplying an optimum print quality by varying a transferring voltage level of a transfer unit after presuming the amount of consumed toner.

Abstract: A color registration adjusting method in an image forming apparatus includes the steps of determining whether the detected pulse width for the edge of a photoreceptor belt is smaller than the expected pulse width thereof. If the detected pulse width is smaller than the expected pulse width, then the detected pulse width is set as a scanning start signal (an edge signal mixed) and a value obtained by subtracting a predetermined value from the currently expected pulse width is set as the next expected pulse width. Alternatively, if the detected pulse width is greater than or equal to the expected pulse width in the first step, the expected pulse width is set as the scanning start signal and a determination is made whether the counted value of a pulse is smaller than an offset value. If the pulse counted value is smaller than the offset value in the step, a value obtained by subtracting a predetermined value from the currently expected pulse width is set as the next expected pulse width.

Abstract: A heating roller driving device for a heating roller of an image forming apparatus. The heating roller driving device includes a motor for supplying the heating roller with a driving force for the heating roller to contact or separate from a photosensitive belt. A motor controller is provided for controlling the operation of the motor, and a main controller is included for providing the motor controller with a predetermined command to operate the motor.