US Patent 8347554 Hinge and door unit

A hinge enabling a plurality of hold-stay members to automatically lock when the door is fully open, increasing the durability of the hinge, and enabling easy release of the hold-stay members. A hinge includes a one-side hinge plate, a plurality of opposing-side hinge plate portions provided along the lengthwise direction of the hinge plate and supported by it, and an open-angle limiting mechanism for stopping, at a specific angle, opening movement of the opposing-side hinge plate portions.