Title:
DELAY CIRCUIT AND ULTRASONIC DIAGNOSTIC DEVICE USING THE DELAY CIRCUIT
Document Type and Number:
Japanese Patent JPH04252507
Kind Code:
A
Abstract:
PURPOSE: To prevent production of noise by changing a delay time continuously only with an electric signal fed to a control terminal.
CONSTITUTION: The delay time is varied by a change in a reverse voltage of varactor diodes VC,VC' of a variable delay line 12 comprising an inductor L and the varactor diodes VC,VC'. Moreover, the resistance of variable resistance circuits 13a, 13b as matching resistors provided to both ends of the variable delay line 12 is varied according to a change in the delay time of the variable delay line 12. Then the impedance of the variable delay line 12 and the variable resistance circuits 13a, 13b, is matched at all times to prevent the deterioration in the delay characteristic due to a change in the delay time.
Inventors:
KONDO TOSHIRO
ISHIDA KAZUNARI
OGAWA TOSHIO
ISHIDA KAZUNARI
OGAWA TOSHIO
Application Number:
JP2514591A
Publication Date:
September 08, 1992
Filing Date:
January 28, 1991
Export Citation:
Assignee:
HITACHI MEDICAL CORP
International Classes:
A61B8/00; G01N29/22; G01N29/44; H03H11/24; (IPC1-7): A61B8/00; G01N29/22; H03H11/24
Attorney, Agent or Firm:
Nishiyama Haruyuki