US 12,321,114 B2
Fixing apparatus having a nip area, and image forming apparatus
Kazuhiro Doda, Yokohama (JP); Tsuguhiro Yoshida, Yokohama (JP); and Kohei Wakatsu, Kawasaki (JP)
Assigned to Canon Kabushiki Kaisha, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Apr. 25, 2023, as Appl. No. 18/306,322.
Application 18/306,322 is a continuation of application No. 17/516,993, filed on Nov. 2, 2021, granted, now 11,669,032.
Application 17/516,993 is a continuation of application No. 17/012,613, filed on Sep. 4, 2020, granted, now 11,194,272, issued on Dec. 7, 2021.
Claims priority of application No. 2019-162957 (JP), filed on Sep. 6, 2019.
Prior Publication US 2023/0259057 A1, Aug. 17, 2023
Int. Cl. G03G 15/20 (2006.01)
CPC G03G 15/2053 (2013.01) [G03G 15/2064 (2013.01); G03G 2215/2038 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A fixing apparatus comprising:
a tubular fixing film;
a pressure roller configured to urge the fixing film;
a nip forming member, which is arranged in an internal space of the fixing film, and is configured to form a nip portion between the fixing film and the pressure roller; and
a heater, which is arranged in the internal space of the fixing film, held by the nip forming member, and is configured to heat, in the nip portion, a toner image on a recording material conveyed from an image forming portion,
wherein the nip forming member includes:
a first projection portion configured to protrude toward the pressure roller in a height direction perpendicular to a conveyance direction of the recording material and a longitudinal direction of the nip forming member, the first projection portion being located on an inner side of the nip portion and on a downstream side of the heater in a conveyance direction of the recording material, and configured to extend along the longitudinal direction and abut against an inner circumferential surface of the fixing film, wherein the first projection portion is disposed to cross a nip tangent of the nip portion in the height direction at a center portion and an end portion of the nip forming portion in the longitudinal direction; and
a second projection portion configured to protrude toward the pressure roller in the height direction, the second projection portion being located on an outer side of the nip portion and on the downstream side of the heater in the conveyance direction, and configured to extend along the longitudinal direction and abut against the inner circumferential surface of the fixing film, wherein the second projection portion is disposed to be curved toward the pressure roller without crossing the nip tangent in the height direction at the center portion and the end portion of the nip forming member in the longitudinal direction,
wherein a distance in the height direction between a top point at the end portion of the second projection portion and the nip tangent at the center portion is larger than a distance in the height direction between a top point at the end portion of the first projection portion and the nip tangent.