Optical disc apparatus, sheet member, and method for cleaning objective lens

An optical disc apparatus, comprising:

• a drive mechanism configured to rotate a medium including a processing surface to be subjected to an optical information process;
• a housing configured to store the drive mechanism;
• a tray mechanism configured to displace the medium between a storage position, at which the medium is stored in the housing, and an ejection position, at which the medium is ejected from the housing;
• at least one objective lens which condenses light onto the processing surface of the medium situated at the storage position to perform the information process;
• and
• a first displacement mechanism configured to displace the at least one objective lens along the processing surface between a first position and a second position which is more distant from a rotational center of the medium rotated by the drive mechanism than the first position is, wherein
• the tray mechanism defines at least one opening in a position closer to the second position than the first position,
• the drive mechanism rotates the medium to cause air flow in the housing,
• the first displacement mechanism places the at least one objective lens at the second position to cause the at least one objective lens to be exposed to the air flow blown from the at least one opening,
• the tray mechanism includes a tray plate defining a rotation space, in which the medium rotates, and an opening piece provided with the at least one opening,
• the tray plate is provided with an opening area to allow the tray mechanism to displace the medium between the storage position and the ejection position, and
• the opening piece is situated so that the at least one opening is overlapped with the opening area.