Title:
AUTOFOCUSING DEVICE FOR AUTOFOCUSING CAMERA
Document Type and Number:
Japanese Patent JPH0297908
Kind Code:
A
Abstract:
PURPOSE:To always accurately perform focusing by varying a focusing ring corresponding to a distance calculated from a time difference between a radio signal transmitted from a camera and a radio signal from an object in response to the signal from the camera. CONSTITUTION:A video camera 1 is equipped with a transmitting and receiving device for autofocusing and also provided with an ultrasonic transmitting window 3 and an ultrasonic receiving window 4. Meanwhile, an ultrasonic transmitter-receiver main body 11 is provided on an object side, which is supposed to be carried by a child. When the radio signal is transmitted from the camera side, the radio signal of the reception is transmitted from the object side in response to the signal from the camera side. the focusing ring 5 is varied corresponding to the distance calculated from the time difference between both radio signals. Therefore, the distance can be calculated from the time difference of ultrasonic even if the object moves and focusing can be accurately performed.
Inventors:
SHIINO SHIGEKI
Application Number:
JP25064588A
Publication Date:
April 10, 1990
Filing Date:
October 04, 1988
Export Citation:
Assignee:
AKAI ELECTRIC
International Classes:
G03B13/36; G02B7/40; G03B19/18; H03J9/04; H04N5/232; (IPC1-7): G02B7/40; G03B13/36; G03B19/18; H03J9/04; H04N5/232
Attorney, Agent or Firm:
Takesaburo Nagata
Next Patent: DARK FIELD ILLUMINATING DEVICE