Optical scanner and color image forming apparatus using the same

An optical scanner comprising

• a plurality of scanning units each having deflecting means having a plurality of deflection surfaces onto which a flux emitted from light source means is directed, and a scanning optical system which forms the flux, reflection-deflected by said deflecting means, into spots on a surface to be scanned, wherein:
• two or more scanning units from among said plurality of scanning units commonly use said deflecting means, and said two or more scanning units use fluxes reflection-deflected on different deflection surfaces of said deflecting means;
• and
• one of the write timings of said two or more scanning units, when the number of said deflection surfaces is three, detects a flux coming via a deflection surface preceding by two surfaces in the rotating direction, for use in obtaining a beam write position detecting signal.

An optical scanner comprising

• a plurality of scanning units each having deflecting means having a plurality of deflection surfaces onto which a flux emitted from light source means is directed, and a scanning optical system which forms the flux, reflection-deflected by said deflecting means, into spots on a surface to be scanned, wherein:
• two or more scanning units from among said plurality of scanning units commonly use said deflecting means, and said two or more scanning units use fluxes reflection-deflected on deflection surfaces not opposite to each other on said deflecting means;
• and
• one of the write timings of said two or more scanning units, when the number of said deflection surfaces is four, detects a flux coming via a deflection surface preceding by three surfaces in the rotating direction, for use in obtaining a beam write position detecting signal.

An optical scanner comprising

• a plurality of scanning units each having deflecting means having a plurality of deflection surfaces onto which a flux emitted from light source means is directed, and a scanning optical system which forms the flux, reflection-deflected by said deflecting means, into spots on a surface to be scanned;
• wherein:
• two or more scanning units from among said plurality of scanning units commonly use said deflecting means;
• and
• one of the write timings of said two or more scanning units, when the number of said deflection surfaces is five, detects a flux coming via a deflection surface preceding by three or four surfaces in the rotating direction, for use in obtaining a beam write position detecting signal.

An optical scanner comprising

• a plurality of scanning units each having deflecting means having a plurality of deflection surfaces onto which a flux emitted from light source means is directed, and a scanning optical system which forms the flux, reflection-deflected by said deflecting means, into spots on a surface to be scanned, wherein:
• two or more scanning units from among said plurality of scanning units commonly use said deflecting means, and said two or more scanning units use fluxes reflection-deflected on deflection surfaces not opposite to each other on said deflecting means;
• and
• one of the write timings of said two or more scanning units, when the number of said deflection surfaces is six, detects a flux coming via a deflection surface preceding by four surfaces in the rotating direction, for use in obtaining a beam write position detecting signal.

An optical scanner comprising

• a plurality of scanning units each having deflecting means having a plurality of deflection surfaces onto which a flux emitted from light source means is directed, and a scanning optical system which forms the flux, reflection-deflected by said deflecting means, into spots on a surface to be scanned, wherein:
• two or more scanning units from among said plurality of scanning units commonly use said deflecting means, and said two or more scanning units use fluxes reflection-deflected on deflection surfaces not opposite to each other on said deflecting means;
• and
• one of the write timings of said two or more scanning units, when the number of said deflection surfaces is eight, detects a flux coming via a deflection surface preceding by six surfaces in the rotating direction, for use in obtaining a beam write position detecting signal.

An optical scanner comprising

• a plurality of scanning units each having deflecting means having a plurality of deflection surfaces onto which a flux emitted from light source means is directed, and a scanning optical system which forms the flux, reflection-deflected by said deflecting means, into spots on a surface to be scanned, wherein:
• two or more scanning units from among said plurality of scanning units commonly use said deflecting means, and said two or more scanning units use fluxes reflection-deflected on deflection surfaces opposite to a rotation axis of said deflecting means;
• and
• one of the write timings of said two or more scanning units, when the number of said deflection surfaces is an even number N (N is 2 or a larger even number), detects a flux coming via a deflection surface preceding by (N−N/2) surfaces in the rotating direction, for use in obtaining a beam write position detecting signal.