Patent ID: 8594597

Claim:
A portable transmitter for transmitting radio waves comprising: a circuit board having a battery that supplies power to the circuit board and an antenna that transmits the radio waves, the battery having a circular cylindrical shape and the circuit board having a circular shape, a diameter of the circuit board being larger than a diameter of the battery, the antenna including two single axis antennas perpendicularly arranged from each other or a pattern-antenna formed by a wiring pattern, the antenna is disposed on an area of the circular circuit board, the area corresponds to an outer region of an outer periphery of the battery; and a case accommodating the battery and the circuit board to be laminated, the case comprising a first case member and a second case member being engaged with each other to form the case, wherein a concave portion is formed on either the first or second case members to accommodate the battery, a lock portion is formed on either the first or second case members to lock the circuit board with either the first case member or the second case member, and while the concave portion accommodates the battery and the circuit board is locked by the lock portion, a surface of the circuit board and a surface of the battery are attached, and the first case member and the second case member are engaged, wherein the battery is arranged to have eccentricity such that a circular center of the battery and a circular center of the circuit board are different from each other, the circuit board includes an area not duplicating with a shape of the battery in a direction where the battery and the circuit board are laminated, the area is being widened, and the antenna is arranged on the widened area.