US Patent 7249361 Optical pickup device

Light from a light source is led to a condensing lens by a light leading unit and is condensed onto an optical recording medium by the condensing lens. Light reflected from the optical recording medium is led to a light sensing device through a spot adjustment lens facing the light sensing device. Between the spot adjustment lens and the light sensing device, a cylindrical dustproof member is provided. The full periphery of an optical path extending between the spot adjustment lens and the light sensing device is covered with the dustproof member. It can prevent intrusion of a foreign matter such as dusts into the optical path extending between the spot adjustment lens and the light sensing device.