Title:
SPRIT VOLTAGE GENERATOR FOR DRIVING LIQUID CRYSTAL
Document Type and Number:
Japanese Patent JP3383110
Kind Code:
B2
Abstract:
PURPOSE: To reduce power consumption by allotting each of two or more voltage supply subsources, which are connected in series to form a voltage supply source, to the voltage supply source of each operational amplifier.
CONSTITUTION: The voltage Vc maintained at a constant value by the use of a constant voltage diode is sustained by a capacitor C1. At this time, the current supplied from the power source line Vcc to the operational amplifier 13 is made to flow through the operational amplifier 14 after being charged in the capacitor C1. Since the current used in the half periods (high voltage side) of the alternated current signals operated by the operational amplifier 13 is reused in the half periods (low voltage side) of the alternated current signals operated by the operational amplifier 14, the current (liquid crystal driving current) flowing in the operational amplifiers, 13a to 13c, 14a to 14c, are both halved. Hence, the power consumption in the operational amplifiers 13, 14 are reduced; in turn, overall power consumption is easily reduced. Even when the voltage of the constant-voltage diode D1 is changed, the voltage Vc is maintained within a specified range by virtue of transistor Tr1, Tr2.
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Inventors:
Tetsuo Murata
Nobuaki Takahashi
Nobuaki Takahashi
Application Number:
JP4465595A
Publication Date:
March 04, 2003
Filing Date:
March 03, 1995
Export Citation:
Assignee:
Sharp Corporation
International Classes:
G02F1/133; G09G3/36; (IPC1-7): G09G3/36; G02F1/133
Domestic Patent References:
| JP63179620A | ||||
| JP6368819A | ||||
| JP2150819A | ||||
| JP63216097A | ||||
| JP3230116A |
Attorney, Agent or Firm:
Kenzo Hara
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