IP Library Granted Patent US 7,619,620
Granted Patent B2
US 7,619,620 · App. 11/431,518 · Granted Nov 17, 2009

Test circuit, electro-optical device, and electronic apparatus

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Quick Facts
Patent No.
US 7,619,620
App. No.
11/431,518
Granted
Nov 17, 2009
Kind
B2
Abstract

A test circuit for detecting an output signal from a driving circuit includes a judging circuit which outputs a detection signal when the output signal output from the driving circuit has one polarity, but does not output the detection signal when the output signal has the other polarity, and an amplifying circuit which amplifies the signal from the judging circuit.

Claims (13)

1. A test circuit for detecting an output signal from a driving circuit, comprising:

a judging circuit which outputs a detection signal when the output signal output from the driving circuit has one polarity, but does not output the detection signal when the output signal has the other polarity; and

an amplifying circuit which amplifies the signal from the judging circuit,

wherein the driving circuit is a demultiplexer which, if a control signal and an inverted control signal obtained by inverting the control signal are input, has a plurality of transfer gates to be turned on/off in synchronization with the control signal and the inverted control signal, and

the judging circuit has a plurality of NOT circuits which individually invert the inverted control signal, a plurality of NAND circuits which correspondingly invert logical products of the output signals from the individual NOT circuits and the control signal corresponding to the inverted control signal, and output the inverted logical products, and a NOR circuit which calculates a negative logical product of the output signals from the plurality of NAND circuits.

2. An electro-optical device comprising:

a plurality of scanning lines;

a plurality of data lines which intersect the scanning lines;

a plurality of pixel circuits which are provided at intersections between the scanning lines and the data lines;

a data line driving circuit which drives the data lines; and

a scanning line driving circuit which drives the scanning lines,

wherein at least one of the data line driving circuit and the scanning line driving circuit has the test circuit according to claim 1 .

3. An electronic apparatus comprising the electro-optical device according to claim 2 .

Assignments (6)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 11, 2025
From: JAPAN DISPLAY INC.
To: MAGNOLIA WHITE CORPORATION
Reel/Frame 072398/0001 →
MERGER AND CHANGE OF NAME Recorded Jul 24, 2025
From: JAPAN DISPLAY EAST INC.; JAPAN DISPLAY WEST INC.
To: JAPAN DISPLAY INC.
Reel/Frame 071935/0063 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 8, 2013
From: SONY CORPORATION
To: JAPAN DISPLAY WEST INC.
Reel/Frame 031378/0243 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 11, 2011
From: EPSON IMAGING DEVICES CORPORATION
To: SONY CORPORATION
Reel/Frame 025935/0327 →
CHANGE OF NAME Recorded Mar 22, 2007
From: SANYO EPSON IMAGING DEVICES CORPORATION
To: EPSON IMAGING DEVICES CORPORATION
Reel/Frame 019066/0784 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 11, 2006
From: FUJITA, SHIN; OKA, HIROKO
To: SANYO EPSON IMAGING DEVICES CORP.
Reel/Frame 017865/0167 →