Patent ID: 7439436

Claim:
A main case body of a musical keyboard instrument having a keyboard unit in which a plurality of keys arranged in a predetermined key arrangement direction, the main case body constructing a case structure of the musical keyboard instrument with at least one sub case body, the main case body comprising: a bottom part extending in a front-rear direction of said main case body; a key supporting part formed such that said key supporting part rises from a rear part of said bottom part of said main case body and extends in the predetermined key arrangement direction, said key supporting part supporting each of the keys of the keyboard unit at a base end of the key; a stopper body formed such that said stopper body rises from a front part of said bottom part of said main case body and extends in the predetermined key arrangement direction, said stopper body stopping a free end of each of the keys of the keyboard unit when the key is operated; and a battery case that accommodates a plurality of batteries between said key supporting part and said stopper body such that a longitudinal direction of the accommodated batteries and a longitudinal direction of the keys of said keyboard unit are parallel to each other, said battery case including therein a plurality of battery terminal-associated parts arranged at both ends of said battery case with respect to the longitudinal directions of the keys.