Patent ID: 7463277

Claim:
A color image forming apparatus for forming color images on a recording medium by superposing images one after another, the apparatus comprising: at least one image bearing member that bears a latent image thereon; a first scanning unit and a second scanning unit, each scanning unit scanning at least two light beams over the at least one image bearing member to form the latent image thereon, and a scanning unit frame in which the first and second scanning units are disposed, the scanning unit frame having lens mounting portions for receiving a spherical lens and at least one cylindrical lens for each scanning unit; wherein the first scanning unit and the second scanning unit each has a spherical lens having an optical axis and a shape substantially symmetrical with respect to the optical axis; wherein each spherical lens is selected from a plurality of lens molded from a plurality of cavities having the same specifications and adapted to be positioned to receive the light beam prior to the light beam being split into at least two beams for transmission to cylindrical lenses and adapted to be oriented in a first position or in a second position rotated 180 degrees about its optical axis from the first position, each spherical lens having first and second position determining portions provided at two locations symmetrical with respect to the optical axis of the lens; and wherein the first position determining portion is capable of engaging with the lens mounting portion when the spherical lens is disposed in a normal orientation, and the second position determining portion is capable of engaging with the lens mounting portion when the lens is disposed in a reverse orientation rotated 180 degrees from the normal orientation about the optical axis.