Light scanning device and image forming apparatus with the same

A light scanning device, comprising:

• a light-emitting element;
• a deflecting section configured to deflect a light beam emitted from the light-emitting element;
• at least one reflective mirror configured to reflect the light beam and cause the light beam to enter a scan object, the light beam being emitted from the light-emitting element and deflected by the deflecting section;
• and
• a BD sensor configured to detect the light beam deflected by the deflecting section, wherein
• the light scanning device is configured to scan the scan object with the light beam and set scanning timing of the scan object using the light beam based on detection timing of the light beam using the BD sensor,
• the BD sensor is mounted on a BD substrate that is disposed outside a side wall of a housing of the light scanning device and that is fixed in a recess provided in the side wall of the housing,
• the light scanning device further includes a detecting mirror configured to reflect the light beam deflected by the deflecting section to cause the light beam to enter the BD sensor,
• the detecting mirror is disposed outside in a main-scanning direction of the scan object relative to the BD sensor,
• the BD sensor is (i) in a position farther from the deflecting section than a particular one of the at least one reflective mirror configured to reflect the light beam, the particular reflective mirror being arranged farthest from the deflecting section, and (ii) inside an arrangement area of a last one of the at least one reflective mirror in a main-scanning direction, the last reflective mirror being configured to reflect the light beam immediately before entering the scan object, and
• the BD sensor is arranged in a position where the light beam enters after the light beam is reflected by the detecting mirror and passes above an upper end or below a lower end of the reflective mirror arranged farthest from the deflecting section.