Image-forming device and light scanning device

An image-forming device, comprising:

• a light source section for outputting a light beam;
• a rotating polygonal mirror for scanning the light beam from the light source section in a main scanning direction;
• an image carrier that is irradiated by the light beam scanned by the rotating polygonal mirror, whereby a latent image is formed;
• a housing for housing the light source section and the rotating polygonal mirror, the housing having an output window through which the light beam scanned in the main scanning direction is outputted towards the image carrier;
• a shutter member that has a ventilation passage formed extending therethrough in the main scanning direction, the shutter member adapted to slide over the outside surface of the housing in a secondary scanning direction orthogonal to the main scanning direction in order to open and shut the output window;
• a cover member provided to open or close the interior of a chassis of the device;
• and
• an actuating mechanism for moving the shutter member to a position where the output window is opened or a position where the output window is closed, in association with an opening up or closing up operation performed by the cover member;
• the shutter member being moved to the closing position by the actuating mechanism when the cover member is opened up, and moved to the opening position by the actuating mechanism when the cover member is closed up;
• and
• the ventilation passage facing a ventilation opening of a duct furnished to the device chassis when the shutter member is in the opening position.