Abstract: A bill validator is provided which comprises a rotator with a slit and being rotatably attached to the bill validator, the slit being capable of aligning with a passageway when the rotator is in an initial position; a driving device for rotating the rotator; and a validator control circuit for judging authenticity of the bill by outputs of detective sensors and for controlling the driving device. The validator control circuit produces outputs to operate the driving device and thereby to rotate the rotator so as to wind some pulling string connected to the bill around the rotator after the bill passes the slit of the rotator, and the circuit evaluates the rotation rate of the rotator, and detects the unauthorized pulling string.

Abstract: A pen for providing input to an electronic apparatus includes a cylindrical pen body made of a resin, a pen tip attached to one end of the pen body, and a weight member disposed within the pen body and offset from the axis of the pen body. The weight member is of a density higher than that of the rein. This allows the center of gravity of the pen body to be radially eccentric with respect to the axis thereof and aids in preventing rolling of the pen.

Abstract: A battery housing structure including a holding portion for holding a battery and a lid for covering the holding portion, the holding portion being arranged on a case of an electronic device, includes a sliding member for slidably moving between a first position and a second position, and a blocking member for preventing the lid from being mounted on the case when the tip of the sliding member is located at the second position. The first position corresponds to a position where a tip of the sliding member comes into contact with the battery when the battery is held on the holding portion, and the second position corresponds to a position where the tip of the sliding member stops when the battery is not held on the holding portion.

Abstract: A memory protection device for an electronic apparatus has a cartridge storage portion for accommodating a memory cartridge. The memory cartridge stores data for the electronic apparatus. This memory protection device further comprises a lid connected to the cartridge storage portion, a sensor for detecting the opened/closed condition of the lid, and a disconnecting circuit which is responsive to the opened condition of the lid for electrically disconnecting the memory cartridge from a control circuit in the electronic apparatus when the cartridge in installed in the cartridge storage portion.

Abstract: Arm mechanism for a pushbutton type tuner including an arm plate for supporting rotatably a frequency defining plate and a plate spring mounted on this arm plate and locking said frequency defining plate at its periphery, whereby a projection is formed at the base portion of said arm plate by embossment both from the upper and lower surfaces of the arm plate.