| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lens diaphragm adjusting apparatus for a closed-circuit television camera, wherein the automatic adjustment of the lens diaphragm and the manual adjustment of that are switchable and the constitution is simple. <P>SOLUTION: The lens diaphragm adjusting apparatus includes: a geared motor GM for driving the diaphragm blade 22 for a lens diaphragm mechanism 14; a driving circuit 130 for driving the geared motor GM in accordance with a first driving signal CS1 for the automatic adjustment or a second driving signal CS2 for the manual adjustment; a comparison circuit for comparing a brightness information signal S1 corresponding to an imaging environment and a first reference signal Vref1 and outputting the first driving signal CS1 for the automatic adjustment; a differential amplifier 120 for outputting the second driving signal CS2 for the manual adjustment in reply to the input of a manual adjustment signal S2 inputted from an operator and the input of a second reference signal Vref 2 that defines the limit value of the driving quantity of the geared motor GM; and a selection circuit 140 for connecting either of the first driving signal CS1 or the second driving signal CS 2 to the driving circuit 130. <P>COPYRIGHT: (C)2008,JPO&INPIT |
