Door support device

A door support device being applied to a vehicle including a vehicle body with a door opening on a side in a width direction, and a slide door that opens and closes the door opening, wherein the slide door opens and closes the door opening by moving between a fully closed position of fully closing the door opening and a fully open position that is displaced from the fully closed position outward in the width direction and in a front-back direction and fully opens the door opening, the door support device comprising:

• a striker unit to be installed in the vehicle body;
• a door bracket extending inward in the width direction from the slide door;
• and
• a lock mechanism to be supported by the door bracket,
• wherein the striker unit includes a striker to be displaced between a retracted position where the striker is stored against the vehicle body and a deployed position where the striker is deployed outward in the width direction from the retracted position, the striker being placed at the retracted position when the slide door is located at the fully closed position and at the deployed position when the slide door is located at the fully open position, and
• the lock mechanism restrains the slide door to the vehicle body by engaging with the striker located at the deployed position when the slide door is located at the fully open position.