| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an automatic electronic flash unit and a camera which have a wide range of measurable luminance, can be simplified in circuit constitution and reduced in arrangement space for a light receiving element, and have good response to follow up even a startup of large-output electronic flash light abruptly varying in quantity well. <P>SOLUTION: An LED 2 or photodiode is used as the light receiving element of the automatic electronic flash unit for the camera. After a voltage based upon the photovoltaic force of the light receiving element is amplified by a MOSFET 9, a capacitor 17 for integration is charged through an amplifying resistance element 11 and a transistor 15 for integration. When the charging voltage of the capacitor 17 for integration exceeds a reference voltage, a comparator 41 turns off a discharge tube 20. <P>COPYRIGHT: (C)2004,JPO |
