| 摘要 |
<p>Aspects of the invention can provide an imaging device that can include a first optical element having a first focal length, and a second optical element having a variable second focal length. The second optical element can be located at a fixed first distance of approximately the first focal length away from the first optical element. Thus, such an imaging device can permit an optical system to focus on an object at various distances and at a constant magnification with no moving parts.</p> |
