Title:
【発明の名称】光一周波数変換器
Document Type and Number:
Japanese Patent JP2687473
Kind Code:
B2
Abstract:
PURPOSE:To attain a wise dynamic range and to enable the execution of accurate photometry and easy adjustment of a light/frequency conversion ratio by a method wherein the polarity of a capacitor of an integrator is changed over by an analog switch, integration is thereby repeated and a frequency proportional to a photocurrent is obtained therefrom. CONSTITUTION:When analog switches 3 and 6 are ON and 4 and 5 OFF, an input current from a photodiode 2 charges a capacitor 7 through the switch 3 and an output voltage of an integrator 1 lowers in the negative direction. When the voltage exceeds a reference voltage -VR of a comparator 8, an output voltage of the comparator 8 is inverted to be positive, a Q output of FF 9 turns to be 0 while a Q' output thereof turns to be 1, and the switches 4 and 5 turn ON while 3 and 6 turn OFF. Accordingly, the polarity of the capacitor 7 changes, the voltage of an output terminal of the integrator 1 changes from -VR to VR, and the output voltage of the integrator 1 starts to lower in the negative direction again. By the repetition of this operation, a pulse signal proportional to a photocurrent is obtained at a terminal 10. When an output frequency is integrated, the frequency for the quantity of light and a unit time is of average intensity. A conversion ratio can be altered by changing a reference value.
Inventors:
Yoshio Komatsu
Application Number:
JP21517288A
Publication Date:
December 08, 1997
Filing Date:
August 31, 1988
Export Citation:
Assignee:
Iwasaki Electric Co., Ltd.
International Classes:
G01J1/44; H03K3/02; H03K3/0231; (IPC1-7): G01J1/44; H03K3/02
Domestic Patent References:
| JP63121719A | ||||
| JP57178117A | ||||
| JP55112533A |