Laser beam scanning optical apparatus

A laser beam scanning optical apparatus in which a laser beam emitted from a laser source is scanned on a scanning surface linearly at a substantially constant speed by a scanner and an optical element, said laser beam scanning optical apparatus comprising:

• focus adjusting means which adjusts a position of an image point of the laser beam;
• focus detecting means which detects a state of a spot of the laser beam on the scanning surface, the focus detecting means having a light receiving surface which is located in a position which is optically substantially equivalent to the scanning surface;
• emission control means which drives the laser source in accordance with image data to write an image on the scanning surface, the emission control means further controlling the laser source to perform fixed point emission so that the laser beam irradiates a discrete point on the light receiving surface of the focus detecting means;
• and
• focus control means which drives the focus adjusting means in accordance with a detection result of the focus detecting means to correct the position of the image point.

A laser beam imaging apparatus, comprising:

• a laser source emitting a laser beam;
• a scanning surface;
• and
• a laser beam scanning optical apparatus for scanning said laser beam on said scanning surface linearly at a substantially constant speed, said laser beam scanning optical apparatus comprising:
• focus detecting means which detects a state of a spot of the laser beam on the scanning surface, the focus detecting means having a light receiving surface which is located in a position which is optically substantially equivalent to the scanning surface;
• and
• emission control means which drives the laser source in accordance with image data to write an image on the scanning surface, the emission control means further controlling the laser source to perform fixed point emission so that the laser beam irradiates a discrete point on the light receiving surface of the focus detecting means.

A laser beam scanning optical apparatus in which a laser beam emitted from a laser source is scanned on a scanning surface linearly at a substantially constant speed by a scanner and an optical element, said laser beam scanning optical apparatus comprising:

• focus adjusting means which adjusts a position of an image point of the laser beam;
• detecting means which detects a state of a spot of the laser beam on the scanning surface, the detecting means having a light receiving surface;
• emission control means which drives the laser source in accordance with image data to write an image on the scanning surface, the emission control means further controlling the laser source to perform fixed point emission so that the laser beam irradiates a point on the light receiving surface of the detecting means;
• and
• focus control means which drives the focus adjusting means in accordance with a detection result of the detecting means to correct the position of the image point.