Keyboard lid opening and closing apparatus and keyboard instrument

A keyboard lid opening and closing apparatus comprising:

• an instrument case provided with a keyboard section;
• a keyboard lid which has a front lid and a rear lid connected by a coupling member such that the keyboard lid is foldable, and exposes the keyboard section in a folded state;
• a rotary fulcrum section which is provided above the keyboard section, and rotates a rear end portion of the rear lid so that the rear lid is held above the keyboard section with a front end portion of the rear lid being positioned higher than the rear end portion of the rear lid, when the keyboard lid exposes the keyboard section;
• a groove section which is provided in an inner surface of the instrument case, and includes a groove extending along an upper side of the keyboard section from a front end portion of the keyboard section to the rotary fulcrum section;
• and
• a guide projection section which is inserted into the groove,
• wherein the guide projection section is positioned at a front end portion of the groove, when the keyboard lid closes the keyboard section, and is moved toward the rotary fulcrum section along the groove, when the keyboard lid exposes the keyboard section, and
• wherein a front end portion of the front lid is guided toward an area below the rotary fulcrum section so that the front lid is held above keyboard section with a rear end portion of the front lid being positioned higher than the front end portion of the front lid, when the keyboard lid exposes the keyboard section.

An operation unit cover opening and closing apparatus comprising:

• a case provided with a operation unit;
• an operation unit cover which has a front cover and a rear cover connected by a coupling member such that the operation unit cover is foldable, and exposes the operation unit in a folded state;
• a rotary fulcrum section which is provided above the operation unit, and rotates a rear end portion of the rear cover so that the rear cover is held above the operation unit with a front end portion of the rear cover being positioned higher than the rear end portion of the rear cover, when the operation unit exposes the operation unit;
• a groove section which is provided in an inner surface of the instrument case, and includes a groove extending along an upper side of the operation unit from a front end portion of the operation unit to the rotary fulcrum section;
• and
• a guide projection section which is inserted into the groove,
• wherein the guide projection section is positioned at a front end portion of the groove, when the operation unit cover closes the operation unit, and is moved toward the rotary fulcrum section along the groove, when the operation unit cover exposes the operation unit, and
• wherein a front end portion of the front cover is guided toward an area below the rotary fulcrum section so that the front cover is held above the operation unit with a rear end portion of the front cover being positioned higher than the front end portion of the front cover, when the operation unit cover exposes the operation unit.