Abstract: A tire state estimation system (10) is provided with a crack shape acquisition unit (240) for acquiring the shape of a crack on the outer surface of a tire, a crack information DB (230) for holding a correspondence relationship in which at least either degree of opening or deviation width of the crack based on the shape of the crack is associated with the depth of the crack, and a crack depth estimation unit (250) for estimating the depth of the crack based on the acquired crack shape and the correspondence relationship.

Abstract: A developing device includes a developer bearer rotatable in a rotation direction and forming a developing range, a holder, and an entrance seal. The holder has a facing face facing the developer bearer upstream from the developing range in the rotation direction, a support face defining a part of an outer face of the developing device, and a relay face extending from one end of the support face to one end of the relay face connected to the facing face to form an acute tip portion closer to the developing range than the one end. The entrance seal has a free end projecting from the one end as a cantilever, and a length of the entrance seal from a tip of the free end of the entrance seal to the one end is shorter than a length of the relay face from the acute tip portion to the one end.

Abstract: A tire state estimation system (10) is provided with a crack shape acquisition unit (240) for acquiring the shape of a crack on the outer surface of a tire, a crack information DB (230) for holding a correspondence relationship in which at least either degree of opening or deviation width of the crack based on the shape of the crack is associated with the depth of the crack, and a crack depth estimation unit (250) for estimating the depth of the crack based on the acquired crack shape and the correspondence relationship.

Abstract: A tire state management system (10) is provided with an image data acquisition unit (210) for acquiring 1st image data acquired by imaging the outer surface at a first timing and second image data acquired by imaging the outer surface at a second timing later than the first timing, a damage portion acquisition unit (220) for acquiring a damage included in the 1st image data and a damage included in the 2nd image data, a vehicle operation information acquisition unit (230) for acquiring operation information of a vehicle on which a tire is mounted, and a maintenance prediction unit (240) for estimating a progress speed based on the damage included in the 1st image data and the progress speed included in the 2nd image data and predicting a maintenance timing for the tire based on the progress speed and the operation information.

Abstract: A pneumatic tire includes a bead part having a bead core, and a carcass layer folded around the bead core in the bead part. The bead part includes a bead inner-face part defined as a region at an inner side of the carcass layer in a tire width direction and at an outer side of a bead toe in a tire radial direction, a bead base part defined as a region at an inner side of the carcass layer in the tire radial direction and at an outer side of the bead toe in the tire width direction, and a high-hardness rubber layer having hardness higher than hardness of the bead base part and provided in at least a part of the bead inner-face part.