| 摘要 |
PURPOSE:To perform high-precision alignment by arranging objectives so that respective focuses are at plural position on an object which need to be aligned, and switching image planes for every alignment position and enlarging an object image. CONSTITUTION:Photoelectric transducers 2a-2d are arranged at plural positions on the object substrate 1. The objectives 4a-4d have the same focal length and are arranged so that their optical axis gaps correspond to position gaps of the transducers 2a-2d. An image forming lens 8 receives parallel luminous flux and forms an image of the transducers 2a-2d on an image pickup surface 10a. Then, the lenses 4a-4d are moved in optical-axis directions so that the transducers 2a-2d are viewed clearly on a TV monitor 12. Then, when the element 2a is aligned, the switch 24a of a shutter control part 22 is turned on to open a shutter 18a while other shutters are closed. Consequently, an image of the transducer 2a is formed on the monitor 12, on the transducer 2a is aligned by utilizing the reticle 26 on the screen. Similarly, the transducers 2b-2d are aligned.
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