LIQUID CRYSTAL DEVICE, METHOD OF DRIVING LIQUID CRYSTAL DEVICE AND ELECTRONIC APPARATUS

• US 20080218648A1
• Filed: 02/15/2008
• Published: 09/11/2008
• Est. Priority Date: 03/06/2007
• Status: Active Grant

• Current Assignee: Japan Display West Incorporated (Japan Display Incorporated)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: UTSUNOMIYA, Sumio, KOSHIHARA, Takeshi
• Granted Patent: US 8,629,858 B2
• Time in Patent Office: Days
• US Class Current: 349/37
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G09G 2300/0876 Supplementary capacities in pixels having special driving circuits and electrodes instead of being connected to common electrode or ground; Use of additional capacitively coupled compensation electrodes
• CPC Class Codes: G09G 3/3655 Details of drivers for counter electrodes, e.g. common electrodes for pixel capacitors or supplementary storage capacitors

Abstract

A liquid crystal device includes a first substrate, a second substrate, liquid crystal which is in between the first and the second substrate, and a detection electrode provided on a side of the first substrate, opposite to a side of the liquid crystal. The second substrate includes pixel electrodes connected through switching elements to signal lines, opposite electrodes formed between the pixel electrodes and the liquid crystal and are connected to control lines, a selection circuit that conducts the switching element during a selection period and interrupts conduction after the selection period has elapsed, a signal supplying circuit which supplies a data electric potential during the selection periods, a electric potential control circuit which sets the control lines to an predetermined electric potential when the scanning lines to the control line is selected and sets to a reference electric potential after the selection period has elapsed.

Claims

1. A liquid crystal device comprising:

a first substrate;

a second substrate that is opposed to the first substrate;

liquid crystal that is sealed in a gap between the first substrate and the second substrate;

a detection electrode that is provided on a side of the first substrate, opposite to a side on which the liquid crystal is provided, wherein the detection electrode detects a contact on the basis of variation in capacitance;

a plurality of scanning lines;

at least one signal line that intersects with the plurality of scanning lines;

a plurality of control lines that are provided in correspondence with the scanning lines;

a plurality of pixel circuits that are formed in the second substrate at positions corresponding to intersections of the at least one signal line and the plurality of scanning lines, wherein each of the plurality of pixel circuits includes a liquid crystal capacitor formed of a pixel electrode that is connected through a switching element to a corresponding one of the at least one signal line, an opposite electrode that is formed between the pixel electrode and the liquid crystal and is connected to a corresponding one of the control lines, and the liquid crystal to which fringe electric field generated between the pixel electrode and the opposite electrode is applied;

a selection circuit that selects each of the plurality of scanning lines in units of selection period, wherein the selection circuit conducts the switching element of the pixel circuit corresponding to the scanning line that is selected during the selection period and interrupts conduction after the selection period has elapsed;

a signal supplying circuit that supplies a data electric potential corresponding to positive polarity writing or negative polarity writing to the signal line during each of the selection periods; and

an electric potential control circuit that sets each of the plurality of control lines, in a selection period when a corresponding one of the scanning lines to the control line is selected, to an electric potential lower than a reference electric potential during the positive polarity writing and to an electric potential higher than the reference electric potential during the negative polarity writing, while setting each of the plurality of control lines to the reference electric potential after the corresponding selection period has elapsed.

2. The liquid crystal device according to claim 1, wherein the detection electrode is formed on a surface of the first substrate, which is opposite to a surface on which the liquid crystal is provided.

3. An electronic apparatus comprising the liquid crystal device according to claim 1.

4. A method of driving a liquid crystal device that includes a first substrate, a second substrate opposed to the first substrate, liquid crystal sealed in a gap between the first substrate and the second substrate, a plurality of scanning lines, at least one signal line that intersects with the plurality of scanning lines, a plurality of control lines that are provided in correspondence with the plurality of scanning lines, a plurality of pixel circuits formed in the second substrate at positions corresponding to intersections of the at least one signal line and the plurality of scanning lines, wherein each of the plurality of pixel circuits includes a liquid crystal capacitor, which is formed of a pixel electrode, an opposite electrode that is formed between the pixel electrode and the liquid crystal and is connected to a corresponding one of the control lines, and the liquid crystal to which fringe electric field generated between the pixel electrode and the opposite electrode is applied, wherein the liquid crystal device further includes a detection electrode that is provided on a side of the first substrate, opposite to a side on which the liquid crystal is provided and that detects a contact on the basis of variation in capacitance, the method comprising:

selecting each of the plurality of scanning lines in units of selection period;

connecting the pixel electrode of the pixel circuit corresponding to the selected scanning line to a corresponding one of the at least one signal line during the selection period and interrupting the pixel electrode of the pixel circuit from a corresponding one of the at least one signal line after the selection period has elapsed;

supplying a data electric potential corresponding to positive polarity writing or negative polarity writing to the signal line during the corresponding selection period;

setting each of the plurality of control lines, in a selection period when a corresponding one of the scanning lines to the control line is selected, to an electric potential lower than a reference electric potential during the positive polarity writing and to an electric potential higher than the reference electric potential during the negative polarity writing, while setting each of the plurality of control lines to the reference electric potential after the corresponding selection period has elapsed.