Abstract: A coupling unit includes two constant velocity joints arranged in series in the shaft direction. The coupling unit couples a driven shaft and a drive shaft. Each constant velocity joint includes a ball non-retaining member and a ball retaining member. The ball non-retaining member has an annular space with one opened end and a plurality of track grooves extending in the shaft direction on an external wall surface of the annular space at a constant interval in a circumferential direction. The ball retaining member has a portion that engages with the annular space of the ball non-retaining member, and that retains a ball that slides along each of the track grooves formed in the ball non-retaining member.

Abstract: There is provided a frame for holding an electronic device, the frame including an inner member that has a shape of continuous or discontinuous loop, and is made of hollow metal having a closed cross-section; and a plurality of corner reinforcing members that are made of metal and are fixed at positions that cover curved portions of the inner member.

Abstract: There is provided a frame for holding an electronic device, the frame including an inner member that has a shape of continuous or discontinuous loop, and is made of hollow metal having a closed cross-section; and a plurality of corner reinforcing members that are made of metal and are fixed at positions that cover curved portions of the inner member.

Abstract: An image forming apparatus includes a driving source, a rotary element and a coupling device. The coupling device includes an inner coupling having a cylindrical shape with a first rotation axis and a first group of claws arranged to be evenly spaced in a circumferential direction, and an outer coupling having a cylindrical shape with a second rotation axis and a second group of claws arranged to be evenly spaced in a circumference direction to alternately mesh with the first group of claws. At least one of the first and second groups of claws includes claws with pointed tips so as to effectively connect the inner coupling with the outer coupling.

Abstract: A coupling unit includes two constant velocity joints arranged in series in the shaft direction. The coupling unit couples a driven shaft and a drive shaft. Each constant velocity joint includes a ball non-retaining member and a ball retaining member. The ball non-retaining member has an annular space with one opened end and a plurality of track grooves extending in the shaft direction on an external wall surface of the annular space at a constant interval in a circumferential direction. The ball retaining member has a portion that engages with the annular space of the ball non-retaining member, and that retains a ball that slides along each of the track grooves formed in the ball non-retaining member.

Abstract: An image forming apparatus includes a driving source, a rotary element and a coupling device. The coupling device includes an inner coupling having a cylindrical shape with a first rotation axis and a first group of claws arranged to be evenly spaced in a circumferential direction, and an outer coupling having a cylindrical shape with a second rotation axis and a second group of claws arranged to be evenly spaced in a circumference direction to alternately mesh with the first group of claws. At least one of the first and second groups of claws includes claws with pointed tips so as to effectively connect the inner coupling with the outer coupling.

Abstract: In an image forming apparatus of the present invention including a plurality of photoconductive drums arranged side by side, each photoconductive drum is configured to allow its opposite end portions in the main scanning direction to be adjusted in maximum eccentricity position in the direction of rotation independently of each other. The maximum eccentricity positions of the drums are capable of being matched in phase to each other in the direction of rotation at each of opposite end portions.

Abstract: In an image forming apparatus of the present invention including a plurality of photoconductive drums arranged side by side, each photoconductive drum is configured to allow its opposite end portions in the main scanning direction to be adjusted in maximum eccentricity position in the direction of rotation independently of each other. The maximum eccentricity positions of the drums are capable of being matched in phase to each other in the direction of rotation at each of opposite end portions.

Abstract: The intermediate sheet feeding device for a duplex image forming apparatus includes: an intermediate tray; an sheet input conveyance path to the intermediate tray; a sheet output conveyance path from the intermediate tray; the sheet input conveyance path and the sheet output conveyance path being arranged to intersect each other at one end of the intermediate sheet tray; a conveying roller provided along the conveyance path from the image processing portion to the intermediate tray; and a conveyance controlling means which controls the conveying roller so as to convey the sheet at a speed lower than that when the sheet advances through the image processing portion and so that a short-sized sheet is conveyed slower than a long-sized sheet.

Abstract: A color image forming apparatus for superimposing images formed on a plurality of photoconductive elements onto a copy sheet includes a sensor for reading a transfer member and a positional deviation detecting pattern formed on the transfer member, a memory for storing information relating to an area having no roughness, such as a scar, on the transfer member, a detector for detecting the area having no roughness on the basis of a signal read by the sensor and for causing the memory to store the information relating to the area, and a color deviation corrector for correcting color deviation on the basis of the signal generated by the sensor reading the positional deviation detecting pattern. The positional deviation detecting pattern is formed at an area of the transfer member having no roughness.