Waveform generator, display device and electronic apparatus

• US 20020036523A1
• Filed: 09/26/2001
• Published: 03/28/2002
• Est. Priority Date: 09/28/2000
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Tam, Simon
• Granted Patent: US 6,600,349 B2
• Time in Patent Office: Days
• US Class Current: 327/131
• CPC Class Codes: H03K 4/023 by repetitive charge or discharge of a capacitor, analogue generators

Abstract

A waveform generator comprising an input terminal connected to one terminal of a first capacitor, a first switch connecting the other terminal of the first capacitor to one terminal of a second capacitor, a second switch connected for operatively discharging the second capacitor, the said one terminal of the second capacitor also being connected to the input of a buffer the output of which is connected to the output of the generator, and a third switch connected so as operatively to feed back the output of the buffer to the other terminal of the first capacitor. The generator can be implemented using polysilicon TFTs. The invention also relates to a display device and to electronic apparatus which include at least one of the described waveform generators.

Claims

1. A waveform generator comprising an input terminal connected to one terminal of a first capacitor, a first switch connecting the other terminal of the first capacitor to one terminal of a second capacitor, a second switch connected for operatively discharging the second capacitor, the said one terminal of the second capacitor also being connected to the input of a buffer the output of which is connected to the output of the generator, and a third switch connected so as operatively to feed back the output of the buffer to the other terminal of the first capacitor.

2. A waveform generator as claimed in claim 1, wherein a low pass filter is connected between the output of the buffer and the output terminal of the generator.

3. A waveform generator as claimed in claim 1 or claim 2, wherein the switches are CMOS switches.

4. A waveform generator as claimed in claim 1, wherein the switches and the buffer are implemented by thin film transistors.

5. A waveform generator as claimed in claim 4, wherein the thin film transistors are formed of polysilicon.

6. A display device including at least one waveform generator as claimed in any of the preceding claims.

7. An electronic apparatus including at least one waveform generator as claimed in any of claims 1 to 5.