Structure for holding optical component, and optical scanning device and image forming apparatus including the same

An optical scanning device comprising:

• a semiconductor laser light source that emits at least one laser beam;
• a collimator lens that is provided on a side of an emission face of the semiconductor laser light source;
• a holding member that holds the collimator lens in a fixed state, and that is a metal-made plate, the holding member having first and second flat plate portions that are provided in a state where the portions stand on a base plate, that are opposed to each other in a state where the flat plate portions are coupled to each other, and that constitute first and second hierarchies, respectively, first and second positioning portions that determine positions of directions of first and second coordinate axes of first, second, and third coordinate axes that intersect with each other being provided at the first flat plate portion, a third positioning portion that determines a position of a direction of the third coordinate axis of the first, second, and third coordinate axes that intersect with each other being provided at the second flat plate portion, a holding portion that is coupled to the first flat plate portion or the second flat plate portion, and that holds the collimator lens;
• and
• a rotary polygon mirror that scans the laser beam that is emitted from the semiconductor laser light source, and that is passed through the collimator lens.

An image forming apparatus comprising:

• a semiconductor laser light source that emits at least one laser beam in accordance with image information;
• a collimator lens that is provided on a side of an emission face of the semiconductor laser light source;
• a holding member that holds the collimator lens in a fixed state, and that is a metal-made plate, the holding member having first and second flat plate portions that are provided in a state where the portions stand on a base plate, that are opposed to each other in a state where the flat plate portions are coupled to each other, and that constitute first and second hierarchies, respectively, first and second positioning portions that determine positions of directions of first and second coordinate axes of first, second, and third coordinate axes that intersect with each other being provided at the first flat plate portion, a third positioning portion that determines a position of a direction of the third coordinate axis of the first, second, and third coordinate axes that intersect with each other being provided at the second flat plate portion, a holding portion that is coupled to the first flat plate portion or the second flat plate portion, and that holds the collimator lens;
• a rotary polygon mirror that scans the laser beam that is emitted from the semiconductor laser light source, and that is passed through the collimator lens;
• and
• an image carrier that is scan-exposed by the laser beam that is scanned by the rotary polygon mirror.