Abstract: A printer includes a top plate, a stabilizer bar, a screw, and a positioning member. The top plate is adapted for a piece of paper located thereon and defines a locking hole. The stabilizer bar is slidably attached to the top plate and defines a through hole and a step-shaped hole. The screw is screwed into the locking hole from the through hole. The positioning member includes a threaded portion. The threaded portion is mounted in the step-shaped hole. A part of the threaded portion extends out of the step-shaped hole, and the part of the threaded portion abuts the top plate.

Abstract: A paper feeding apparatus includes a bracket. A first feeding shaft is pivotably mounted on the bracket. A number of first feeding rollers is mounted on the first feeding shaft. The first feeding rollers rotate together with the first feeding shaft to contact a sheet of paper and move the paper forwards. A number of fans are mounted on the first feeding shaft. The fans rotate together with the first feeding shaft to drive air against the paper to prevent it becoming wrapped around one of the rollers.

Abstract: A transmission device includes a bracket, a belt, a driven module, and a limiting member. The bracket includes a mounting plate and a limiting piece extending from the mounting plate. The idle module is slidably mounted to the mounting plate. The belt is engaged with the idle module and preventing the idle module from sliding along a first direction relative to the mounting plate. The limiting member is located in a side of the idle module and rotatably mounted to the limiting piece. The limiting member abuts the idle module along the first direction, to prevent the idle module from sliding along a second direction, which is opposite to the first direction.

Abstract: A printer includes a top plate, a stabilizer bar, a screw, and a positioning member. The top plate is adapted for a piece of paper located thereon and defines a locking hole. The stabilizer bar is slidably attached to the top plate and defines a through hole and a step-shaped hole. The screw is screwed into the locking hole from the through hole. The positioning member includes a threaded portion. The threaded portion is mounted in the step-shaped hole. A part of the threaded portion extends out of the step-shaped hole, and the part of the threaded portion abuts the top plate.

Abstract: A sheet feeding apparatus includes a tray, a driving mechanism disposed above the tray, a separating mechanism rotatably connected to the tray, and at least one resilient element to provide a constant pressure against the separating mechanism. The driving mechanism includes at least one roller to move one of the sheets. The separating mechanism includes at least one retard pad to separate the sheets and create frictional resistance between the separating mechanism and the stack of the sheets. When the tray has only a few sheets left, the separating mechanism is rotated and the frictional resistance is reduced.

Abstract: A sheet feeding apparatus includes a tray, a driving mechanism disposed above the tray, a separating mechanism rotatably connected to the tray, and at least one resilient element to provide a constant pressure against the separating mechanism. The driving mechanism includes at least one roller to move one of the sheets. The separating mechanism includes at least one retard pad to separate the sheets and create frictional resistance between the separating mechanism and the stack of the sheets. When the tray has only a few sheets left, the separating mechanism is rotated and the frictional resistance is reduced.

Abstract: A paper-feeding mechanism for a printing apparatus includes a delay engaging member and an unidirectional engaging member. The delay engaging member has a first gear and a first coupling member installed on the first gear. The first coupling member rotates relative to the first gear. The unidirectional engaging member has a third gear installed on the first coupling member. When a sheet of paper is pulled out along a first direction, the first gear rotates along a second direction that is opposite to the first direction. The first coupling member rotates along the second direction together with the first gear. The first gear stops rotating. The third gear and the first coupling member rotate along the second direction until the paper(s) caught in the printing apparatus are pulled out.

Abstract: A paper-feeding mechanism for a printing apparatus includes a delay engaging member and an unidirectional engaging member. The delay engaging member has a first gear and a first coupling member installed on the first gear. The first coupling member rotates relative to the first gear. The unidirectional engaging member has a third gear installed on the first coupling member. When a sheet of paper is pulled out along a first direction, the first gear rotates along a second direction that is opposite to the first direction. The first coupling member rotates along the second direction together with the first gear. The first gear stops rotating. The third gear and the first coupling member rotate along the second direction until the paper(s) caught in the printing apparatus are pulled out.

Abstract: A waste ink collecting device includes a ratchet wheel defining a receiving groove for receiving waste ink, a detent, a reciprocatingly movable transmission pole, and immovable first and second poles. The detent includes a hook, and a main body defining elongated first, second and third holes. The second hole is between the first and third holes. The hook extends from the main body away from the first hole. The transmission pole extends into the first hole. The first pole extends into the second hole. A diameter of the first pole equals to a width of the second hole. The second pole extends into the third hole. A diameter of the second pole is smaller than a width of the third hole. When the transmission pole moves forward, the hook engages with and rotates the ratchet wheel. When the transmission pole moves backward, the hook moves away from the ratchet wheel.

Abstract: A waste ink collecting device includes a ratchet wheel defining a receiving groove for receiving waste ink, a detent, a reciprocatingly movable transmission pole, and immovable first and second poles. The detent includes a hook, and a main body defining elongated first, second and third holes. The second hole is between the first and third holes. The hook extends from the main body away from the first hole. The transmission pole extends into the first hole. The first pole extends into the second hole. A diameter of the first pole equals to a width of the second hole. The second pole extends into the third hole. A diameter of the second pole is smaller than a width of the third hole. When the transmission pole moves forward, the hook engages with and rotates the ratchet wheel. When the transmission pole moves backward, the hook moves away from the ratchet wheel.