Title:
IMAGE SENSOR DRIVING CIRCUIT
Document Type and Number:
Japanese Patent JPH02219367
Kind Code:
A
Abstract:
PURPOSE:To make the output of a subtracting circuit stable near a dark level by providing difference between a reference voltage and the charge voltage of an image sensor, to operate the subtracting circuit in the linear area of an output characteristic in the subtracting circuit. CONSTITUTION:The charging voltage of image sensors A-Z are set smaller than a reference voltage VR only by a prescribed value VOF2. Afterwards, reset switches 6a-6z are turned off and a switch 7 is turned on. Then, a switch 9 is turned off and the image sensors A-Z are irradiated with light. In such a case, the charging voltage of the image sensors A-Z are lowered in correspondence to the quantity of the irradiating light. Afterwards, difference between the output voltage of voltage follower circuits 1a-1z and the voltage VR is successively outputted from a subtracting circuit 4 according to the signal of a logic circuit 10. At such a time, since the difference VOF2 is provided between the voltage VR and the charging voltage of the image sensor, the output of the circuit 4 is in a linear area (a) even when the quantity of the light, with which the image sensors A-Z are irradiated, is small. As a result, the output is not made instable near the dark level.
Inventors:
NISHIKAWA EIJI
FUSATANI AKIHIKO
YAMAGUCHI HIDEHIKO
TAKEUCHI MASAMI
MIKI HIROMI
MORISANE SHIZUO
FUSATANI AKIHIKO
YAMAGUCHI HIDEHIKO
TAKEUCHI MASAMI
MIKI HIROMI
MORISANE SHIZUO
Application Number:
JP4064089A
Publication Date:
August 31, 1990
Filing Date:
February 20, 1989
Export Citation:
Assignee:
MITSUBISHI ELECTRIC CORP
FUJI XEROX CO LTD
FUJI XEROX CO LTD
International Classes:
G01J1/44; H04N1/04; H04N1/19; H04N1/40; H04N1/407; H04N5/335; H04N5/341; H04N5/357; H04N5/374; H04N5/376; (IPC1-7): G01J1/44; H04N1/04; H04N1/40; H04N5/335
Attorney, Agent or Firm:
Masuo Oiwa (2 outside)