Abstract: An image forming apparatus includes an image forming part for forming an image described by a video signal on a recording sheet by carrying out an image forming operation which includes scans in main and sub scan directions, a storage part for storing test pattern data which describes at least one test pattern to be formed on the recording sheet, a generator for generating a generation interval of the video signal in the main and sub scan directions responsive to the test pattern data stored in the storage part, and a controller for controlling the image forming operation of the image forming part by supplying to the image forming part the video signal which describes an arbitrary test pattern and is generated based on the test pattern data read from the storage part with the generation interval generated by the generator.

Abstract: An image recording apparatus includes an image recording media, an optical scanning system selected from among predetermined different optical scanning systems, a first memory for storing a plurality of sets of control data respectively provided for the different optical scanning systems, a switch for specifying one of the predetermined different optical scanning systems provided in the image recording apparatus, and a second memory for storing one of the sets of control data corresponding to the optical scanning system selected from among the predetermined different optical scanning systems.

Abstract: A duplex unit has a reversing part for reversing sides of recording sheets and a stack part for successively stacking the reversed recording sheets, where the stacked recording sheets are outputted in a first-in-first-out sequence. This duplex unit is suited for use on an image forming apparatus which records images on both sides of the recording sheets by an electrophotography.

Abstract: A sheet transport apparatus is used in a duplex image forming apparatus which makes two-sided prints. The sheet transport apparatus has a transport path for supplying a recording sheet which is received from a paper supplying unit to an image forming part, a reversing path for reversing side of the recording sheet, and two driving sources for independently driving mechanisms which transport the recording sheet in each of the transport path and the reversing path.

Abstract: A method of controlling an optical output of a laser light source which scans a photosensitive body comprises the steps of detecting an optical output of the laser light source and generating a monitor signal which has a logic level indicative of whether a laser power of the optical output is greater than or less than a predetermined value, generating signals including a gate signal indicative of a scan time in which the photosensitive body is scanned based on a synchronization detection signal indicative of each scanning line, a laser diode signal having logic levels for turning the laser light source ON and OFF and an enable signal based on the monitor signal, the gate signal and a power set start signal indicative of a start of a power set operation in which the laser power is controlled to the predetermined value, and adjusting a driving current supplied to the laser light source based on the monitor signal when enabled by a certain logic level of the enable signal so as to control the laser power to the

Abstract: A sheet feeding apparatus suitable for use in combination with an imaging system, such as a copier or printer, for feeding sheets of paper one by one to the imaging system is provided. The apparatus includes a predetermined path along which a sheet of paper is transported and a sensor for detecting the presence of a sheet of paper in a predetermined region of the path. When paper jamming of another sheet of paper is detected, if the sensor detects the presence of a sheet of paper in the predetermined region, a controller controls such that the sheet of paper in the predetermined region is transported in the reversed direction so that the sheet of paper is returned to a paper storing section for use in the next cycle of operation. With such a structure, any sheet of paper left unused in the travelling path when paper jamming of another sheet of paper has occurred is automatically returned to its storage so that the operator is not required to remove this unused sheet of paper.