Fixing device and image forming apparatus incorporating same

A fixing device comprising:na thermal member that is stationary and at least partially tubular, the thermal member having a tubular portion extending in an axial direction and defining a closed axial cross-section, and a circumference of the thermal member is subjected to heating;a flexible fuser belt looped for rotation around the thermal member, an inner circumference of the flexible fuser belt at least partially facing the thermal member to transfer heat from the circumference of the thermal member;a fuser pad held stationary inside the loop of the flexible fuser belt; anda rotatable pressure member extending opposite the thermal member in the axial direction with the flexible fuser belt interposed between the fuser pad and the rotatable pressure member,wherein the fuser pad is pressed against the rotatable pressure member through the flexible fuser belt to form a fixing nip through which a recording medium is passed to fix a toner image on the recording medium under heat and pressure,wherein the thermal member is spaced apart from the fuser pad, so as to isolate the thermal member from pressure transmitted through the fuser pad from the rotatable pressure member, andwherein a first gap between adjacent surfaces of the thermal member and the fuser pad is substantially the same as a second gap between adjacent surfaces of the thermal member and the flexible fuser belt.

A fixing device comprising:na thermal member that is stationary and at least partially tubular, the thermal member having a tubular portion extending in an axial direction and defining a closed axial cross-section, and a circumference of the thermal member is subjected to heating;a flexible fuser belt looped for rotation around the thermal member, an inner circumference of the flexible fuser belt at least partially facing the thermal member to transfer heat from the circumference of the thermal member;a fuser pad held stationary inside the loop of the flexible fuser belt;a rotatable pressure member extending opposite the thermal member in the axial direction with the flexible fuser belt interposed between the fuser pad and the rotatable pressure member; andlubricant retaining means including an elastic sponge that retains lubricant for supply between the flexible fuser belt and the thermal member, the elastic sponge being disposed outside the tubular portion of the thermal member and out of sliding contact with the inner circumference of the flexible fuser belt, which is impregnated with lubricant to be released to the inner circumference of the flexible fuser belt,wherein the fuser pad is pressed against the rotatable pressure member through the flexible fuser belt to form a fixing nip through which a recording medium is passed to fix a toner image on the recording medium under heat and pressure, andwherein the thermal member is spaced apart from the fuser pad, so as to isolate the thermal member from pressure transmitted through the fuser pad from the rotatable pressure member.

A fixing device comprising:na thermal member that is stationary and at least partially tubular, the thermal member having a tubular portion thereof extending in an axial direction and defining a closed axial cross-section, and a circumference of the thermal member is subjected to heating;a flexible fuser belt looped for rotation around the thermal member, an inner circumference of the flexible fuser at least partially facing the thermal member to transfer heat from the circumference of the thermal member;a fuser pad held stationary inside the loop of the flexible fuser belt; anda rotatable pressure member extending opposite the thermal member in the axial direction with the flexible fuser belt interposed between the fuser pad and the rotatable pressure member,wherein the fuser pad is pressed against the rotatable pressure member through the flexible fuser belt to form a fixing nip through which a recording medium is passed to fix a toner image on the recording medium under heat and pressure,wherein the thermal member is spaced apart from the fuser pad, so as to isolate the thermal member from pressure transmitted through the fuser pad from the rotatable pressure member, andwherein the thermal member comprises a pipe formed of metal with a thickness of approximately 0.2 millimeters or less.

An image forming apparatus comprising:nan electrophotographic imaging unit to form a toner image on a recording medium; anda fixing device to fix the toner image in place on the recording medium, the fixing device including:na thermal member that is stationary and at least partially tubular, the thermal member having a tubular portion extending in an axial direction and defining a closed axial cross-section, and a circumference of the thermal member is subjected to heating;a flexible fuser belt looped for rotation around the thermal member, an inner circumference of the flexible fuser belt at least partially facing the thermal member to transfer heat from the circumference of the thermal member;a fuser pad held stationary inside the loop of the flexible fuser belt; anda rotatable pressure member extending opposite the thermal member in the axial direction with the flexible fuser belt interposed between the fuser pad and the rotatable pressure member,wherein the fuser pad is pressed against the rotatable pressure member through the flexible fuser belt to form a fixing nip through which the recording medium is passed to fix the toner image on the recording medium under heat and pressure,wherein the thermal member is spaced apart from the fuser pad, so as to isolate the thermal member from pressure transmitted through the fuser pad from the rotatable pressure member, andwherein a first gap between adjacent surfaces of the thermal member and the fuser pad is substantially the same as a second gap between adjacent surfaces of the thermal member and the flexible fuser belt.