Abstract: A printing apparatus includes: a frame; a platen roller configured to be rotated; a movable body supported by the frame, to be movable in a first direction and a second direction; an AC motor provided on the frame; a transmission device provided on the frame, transmitting driving force of the AC motor to the movable body, moving the movable body in the first direction in accordance with rotation of the AC motor toward one side, and including at least an electromagnetic clutch; an encoder outputting a rotation signal in accordance with a rotation amount of the platen roller; and a controller. The controller starts the rotation of the AC motor toward the one side, determines whether the rotation amount of the platen roller in accordance with the rotation signal is not more than a predetermined value, and allows the electromagnetic clutch to be in a connected state.

Abstract: A printing apparatus includes: a frame; a platen roller configured to be rotated; a movable body supported by the frame, to be movable in a first direction and a second direction; an AC motor provided on the frame; a transmission device provided on the frame, transmitting driving force of the AC motor to the movable body, moving the movable body in the first direction in accordance with rotation of the AC motor toward one side, and including at least an electromagnetic clutch; an encoder outputting a rotation signal in accordance with a rotation amount of the platen roller; and a controller. The controller starts the rotation of the AC motor toward the one side, determines whether the rotation amount of the platen roller in accordance with the rotation signal is not more than a predetermined value, and allows the electromagnetic clutch to be in a connected state.

Abstract: An image forming apparatus, having an exposing unit for exposing a photosensitive body to form a_latent image, a developing unit for forming a developer image corresponding to the latent image, a carrier body moved through a portion opposite to the photosensitive body onto which the developer image formed on the photosensitive body is transferred, a mark forming unit for controlling the exposing unit to form a mark on a surface of the carrier body, a light sensor for sensing light reflected by the carrier body, an edge detector for sensing an edge of the mark on the carrier body based on an_output of the light sensor and a deciding unit for deciding a positional relation between a focal point of the exposing unit and the surface of the photosensitive body based on the edge detected by the edge detector.

Abstract: An image forming apparatus, having an exposing unit for exposing a photosensitive body to form an latent image, a developing unit for forming a developer image corresponding to the latent image, a carrier body moved through a portion opposite to the photosensitive body onto which the developer image formed on the photosensitive body is transferred, a mark forming unit for controlling the exposing unit to form a mark on a surface of the carrier body, light a sensor for sensing light reflected by the carrier body, an edge detector for sensing an edge of the mark on the carrier body based on output of the light sensor and a deciding unit for deciding a positional relation between a focal point of the exposing unit and the surface of the photosensitive body based on the edge detected by the edge detector.

Abstract: An image-forming device includes a pattern data generating unit, an image-forming unit and a detecting unit. The pattern data generating unit generates pattern data indicative of a pattern of a plurality of marks. The plurality of marks includes a first mark having a first color, a first light reflectance, a first width in a predetermined direction and a first dot density and a second mark having a second color, a second light reflectance, a second width in the predetermined direction and a second dot density. A difference between a target light reflectance and the first light reflectance is greater than a difference between a target light reflectance and the second light reflectance. At least one of the first mark width and the first dot density is smaller and lower than the second mark width and the second dot density. The image-forming unit forms the plurality of marks at positions on a target having the target light reflectance, based on the pattern data.