Optical scanning device and image forming apparatus including same

An image forming apparatus, comprising:

• an image bearing member to bear an electrostatic latent image on a surface thereof;
• a developing device to develop the electrostatic latent image formed on the image bearing member using toner to form a toner image;
• a transfer device to transfer the toner image onto a recording medium;
• a fixing device to fix the toner image;
• and
• an optical scanning device that exposes the image bearing member to form the electrostatic latent image thereon,
• the optical scanning device including:
• a light source to project a light beam;
• an optical system;
• and
• a housing, including a holder, to enclose the optical system,
• the optical system including a liquid crystal element held by the housing via the holder, to modulate a phase of the light beam projected from the light source against a scanned surface,
• the liquid crystal element including:
• a first substantially transparent substrate having a first surface;
• a second substantially transparent substrate positioned in the holder and having a second surface which opposes the first surface, wherein the second surface has a total area which is larger than a total area of the first surface;
• the second surface further comprising an overlapping area which overlaps with the first surface, and a non-overlapping area that does not overlap with the first surface;
• a liquid crystal layer disposed between the first surface and the second surface in the overlapping area;
• a sealing member disposed between the first surface and the second surface in the overlapping area to seal the liquid crystal layer between the first and second surfaces;
• wherein the second substantially transparent substrate is positioned relative to the holder at the non-overlapping area.