1. An image reading apparatus comprising: a main unit having a document support surface configured to support a document on the document support surface, the main unit including a frame member holding edges of the document support surface, the frame member having: a first surface being adjacent to the document support surface and extending in a first direction parallel to the document support surface; a second surface extending in a second direction substantially orthogonal to the document support surface; and a third surface being continuous with the second surface and facing the first surface at a specified distance from the first surface in the second direction; a reading unit accommodated in the main unit and configured to read an image of the document supported on the document support surface; and an openable unit coupled to the main unit and configured to pivot about a pivot axis between a closed position where the document support surface of the main unit is covered and a released position where the document support surface of the main unit is exposed, the openable unit having a facing surface that, when the openable unit is in the closed position, faces the first surface of the frame member of the main unit, wherein one of the second surface of the frame member of the main unit and the facing surface of the openable unit includes a protrusion that, when the openable unit is in the closed position, protrudes toward the other of the second surface of the frame member of the main unit and the facing surface of the openable unit, and wherein the pivot axis of the openable unit extends in parallel to an edge of the document support surface, and the pivot axis is located between the second surface and the edge of the document support surface in the first direction and between the first surface and the third surface in the second direction.
1. An image reading apparatus comprising: a main unit having a document support surface configured to support a document on the document support surface, the main unit including a frame member holding edges of the document support surface, the frame member having: a first surface being adjacent to the document support surface and extending in a first direction parallel to the document support surface; a second surface extending in a second direction substantially orthogonal to the document support surface; and a third surface being continuous with the second surface and facing the first surface at a specified distance from the first surface in the second direction; a reading unit accommodated in the main unit and configured to read an image of the document supported on the document support surface; and an openable unit coupled to the main unit and configured to pivot about a pivot axis between a closed position where the document support surface of the main unit is covered and a released position where the document support surface of the main unit is exposed, the openable unit having a facing surface that, when the openable unit is in the closed position, faces the first surface of the frame member of the main unit, wherein one of the second surface of the frame member of the main unit and the facing surface of the openable unit includes a protrusion that, when the openable unit is in the closed position, protrudes toward the other of the second surface of the frame member of the main unit and the facing surface of the openable unit, and wherein the pivot axis of the openable unit extends in parallel to an edge of the document support surface, and the pivot axis is located between the second surface and the edge of the document support surface in the first direction and between the first surface and the third surface in the second direction. 2. The image reading apparatus according to claim 1 , wherein the second surface of the frame member of the main unit includes the protrusion that, when the openable unit is in the closed position, protrudes toward the facing surface of the openable unit.