PURPOSE: To effectively prevent the abnormal light emission of a light source, by applying gating so that an electromagnetic wave having other wavelength is not outputted for the predetermined period after an electromagnetic wave having a specific wavelength is outputted from a light source.
CONSTITUTION: A timing circuit 2 is connected to the system bus of a computer system along with a light source control apparatus 3. The timing circuit 2 consists of a counter 4 and a flip-flop 5 and has a function for preventing other light source control signal LAC from being applied to the light source control apparatus 3 within the predetermined period after one light source control signal LAC is applied from the computer system. That is, the counter 4 in the timing circuit 2 counts the predetermined period from the point of time when one light source control signal LAC is generated to output a counter signal CNT. The flip-flop 5 outputs a gate signal GT turned ON when one light signal control signal LAC is generated and turned OFF at the point of time when the counter signal CNT is applied.
SUZUKI SUSUMU
OZAKI TAKEO
HAKAMATA NAOTOSHI
