| 摘要 |
PURPOSE:To enable variable power simply, by moving an in-mirror lens in parallel with an optical path so that the radiated angle from the 2nd mirror to the in-miller lens can be changed in moving the 2nd mirror and the in-mirror lens at variable power. CONSTITUTION:An original image is projected on a photoreceptor 1 via the 1st mirror 2, the 2nd mirror 2', an in-mirror lens 1, and the 4th mirror 6. Thus, to achive variable power, the 2nd mirror 2' is moved to the P-P' position and the in-mirror lens 1 is to the Q-Q' position respectively to change the radiation angle from the 2nd mirror 2' to the in-mirror lens 1, from angle theta1 to theta2(theta1 theta2). In this case, the in-mirror lens 1 is moved in parallel with the optical axis and the variable power can be made without any complicated operation and components, through the movement of the 2nd mirror 2' and the in-mirror lens 1 only. |
