AMPLIFIER, LIQUID CRYSTAL DISPLAYING DRIVING CIRCUIT AND LIQUID CRYSTAL DISPLAY APPARATUS

• US 20130016087A1
• Filed: 06/26/2012
• Published: 01/17/2013
• Est. Priority Date: 07/15/2011
• Status: Active Grant

• Current Assignee: Saturn Licensing LLC (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kishikawa, Teisuke
• Granted Patent: US 9,520,848 B2
• Time in Patent Office: Days
• US Class Current: 345/212
• CPC Class Codes: G09G 2310/0291 Details of output amplifiers or buffers arranged for use in a driving circuit
• CPC Class Codes: G09G 3/3688 suitable for active matrices only
• CPC Class Codes: H03F 2203/45466 the CSC being controlled, e.g. by a signal derived from a non specified place in the dif amp circuit
• CPC Class Codes: H03F 2203/45471 the CSC comprising one or more extra current sources
• CPC Class Codes: H03F 3/3022 CMOS common source output SEPP amplifiers H03F3/3008 takes precedence
• CPC Class Codes: H03F 3/45183 Long tailed pairs H03F3/4521, H03F3/45237 take precedence

Abstract

Disclosed herein is an amplifier including a voltage follower circuit having differential input terminals and an output terminal fed back to a first one of the differential input terminals, the voltage follower circuit being configured to amplify an input signal inputted to a second one of the differential input terminals and output the amplified signal from the output terminal; a first current source configured to supply a predetermined current to the voltage follower circuit; and a second current source configured to supply current to the voltage follower circuit when a potential difference between the second one of the differential input terminals and the output terminal is equal to or higher than a predetermined value.

Claims

1. An amplifier, comprising:

a voltage follower circuit having differential input terminals and an output terminal fed back to a first one of the differential input terminals, the voltage follower circuit being configured to amplify an input signal inputted to a second one of the differential input terminals and output the amplified signal from the output terminal;

a first current source configured to supply a predetermined current to said voltage follower circuit; and

a second current source configured to supply current to said voltage follower circuit when a potential difference between the second one of the differential input terminals and the output terminal is equal to or higher than a predetermined value.

2. The amplifier according to claim 1, wherein said second current source supplies the current to said voltage follower circuit when the potential at the second one of the differential input terminals is higher by a predetermined value or more than the potential at the output terminal.

3. The amplifier according to claim 1, wherein said second current source supplies the current to said voltage follower circuit when the potential at the second one of the differential input terminals is lower by a predetermined value or more than the potential at the output terminal.

4. A liquid crystal displaying driving circuit for outputting a driving signal for driving pixels provided in a liquid crystal displaying section operative to display an image, comprising:

a digital-to-analog conversion circuit configured to generate a driving analog signal in response to an input video signal; and

an amplifier including

a voltage follower circuit having differential input terminals and an output terminal fed back to a first one of the differential input terminals, the voltage follower circuit being configured to amplify the driving analog signal inputted to a second one of the differential input terminals and output the amplified signal from the output terminal,

a first current source configured to supply a predetermined current to the voltage follower circuit, and

a second current source configured to supply current to the voltage follower circuit when a potential difference between the second one of the differential input terminals and the output terminal is equal to or higher than a predetermined value.

5. A liquid crystal display apparatus, comprising:

a driving circuit including

a decoder circuit configured to decode an input signal to produce an input video signal,

a digital-to-analog conversion circuit configured to generate a driving analog signal in response to the input video signal, and

an amplification circuit including a plurality of amplifiers each including

a voltage follower circuit having differential input terminals and an output terminal fed back to a first one of the differential input terminals, the voltage follower circuit being configured to amplify the driving analog signal inputted to a second one of the differential input terminals and output the amplified signal from the output terminal,

a first current source configured to supply a predetermined current to the voltage follower circuit, and

a second current source configured to supply current to the voltage follower circuit when a potential difference between the second one of the differential input terminals and the output terminal is equal to or higher than a predetermined value; and

a liquid crystal displaying section including a plurality of pixels driven by the driving signal and configured to display an image.