| 摘要 |
<p>PURPOSE:To realize a miniature, inexpensive system whose aperture adjustment is facilitated by performing the luminous photometry of a substance surface by forming a reflective surface in a semitransparent reflective surface and then by providing a light quantity detection part behind the semitransparent reflective surface. CONSTITUTION:To measure the brightness of subject surface P, light from subject surface P enters light quantity detection part 4 by way of image-forming lens system L, aperture 1 and semitransparent reflective surface 2. From the exposure obtained by light quantity detection part 4, the proper exposure for copying or photographing is determined to adjust aperture 1 automatically. In the copying or photographing, the light from subject surface P passes through image-forming lens system L and aperture 1, is reflected by semitransparent reflective surface 2 and passes through aperture 1 and image-forming lens system L to form its image on image surface Q.</p> |
