Range detection optical system with light emitter behind projection lens focal point and light receiver behind receiving lens focal point

A range detection optical system, for detecting a range of an object, comprising:

• a light projection system for projecting light flux onto the object, including
• a light emission source emitting the light flux, and
• a light projection lens disposed to receive the light flux from said light emission source and direct the light flux along an optical axis of said light projection system and onto the object, said light projection lens having a focal point between said light emission source and a surface of said light projection lens closest to said light emission source;
• and
• a light receiving optical system for condensing reflected light flux from the object and measuring a range to the object from said range detection optical system, including
• a light receiving lens, and
• a light receiving element disposed a first predetermined distance from said light receiving lens along an optical axis of said light receiving optical system, the optical axis of said light projection system and the optical axis of said light receiving optical system positioned a second predetermined distance from each other, said light receiving element producing an output for determining the range by indicating deviation of the reflected light flux from the optical axis of said light receiving optical system.