Transfer device and image forming apparatus having nip member with predetermined geometry

A transfer device comprising:

• a transfer drum that has a groove-like recess extending in an axial direction in an outer circumferential portion thereof, rotates about an axis thereof, and comes into contact with a medium being transported at a portion thereof on an upstream side of the recess in a rotation direction;
• a nip member, the nip member and the transfer drum forming therebetween a nip part where the medium is nipped;
• and
• an application member that applies a voltage to the nip part where the medium is nipped, so that an image is transferred to the medium,
• wherein the nip member has a columnar or cylindrical shape extending in the axial direction, and an outside diameter of the nip member is smaller than an opening width of the recess in the circumferential direction, such that the nip member comes into contact only with a portion on the upstream side of the recess in the transfer drum in the rotation direction at a transfer-start time when the transfer of the image to the medium starts.