Abstract: A printer includes a printer body and a lid. The printer body includes a recording paper holder configured to accommodate a roll of recording paper and a projection provided on a bottom surface of the recording paper holder that contacts the recording paper. The lid is attached to the printer body to be opened and closed relative to the printer body.

Abstract: A platen roller fixing structure includes a platen roller; a spring; a spring supporting part supporting the spring; a print head; a platen roller receiving part configured to receive the platen roller; and a spring receiving part configured to receive the spring. The platen roller, the spring, and the spring supporting part are provided on one of a body part and a movable part of a printer. The movable part is rotatably connected to the body part. The print head, the platen roller receiving part, and the spring receiving part are provided on the other one of the body part and the movable part. When the movable part is closed relative to the body part, the spring receiving part comes into contact with the spring to cause the spring to press the platen roller against the platen roller receiving part.

Abstract: An inserting connector connected to a receiving connector, the receiving connector being configured to electrically connect an electric power source and an electric apparatus receiving an electric power supply from the electric power source, the inserting connector being connected to the electric apparatus, the inserting connector includes two electric power plug terminals made of a conductor, the conductor being configured to receive the electric power supply; and a control plug terminal configured to be extended and retracted in an inserting direction.

Abstract: A printing apparatus configured to carry out printing on paper with a printing head, while holding the paper between the printing head and a platen roller, includes: a paper guide block guiding the paper in between the printing head and the platen roller, and holding the platen roller; and a force applying member applying a force to any one of the paper guide block and the printing head in such a manner as to press the any one of the paper guide block and the printing head.