DISPLAY DEVICE AND METHOD FOR DRIVING DISPLAY DEVICE

• US 20100238156A1
• Filed: 08/28/2008
• Published: 09/23/2010
• Est. Priority Date: 01/24/2008
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Nissha Printing Company Limited (Nissha Co., Ltd.)
• Inventors: Morii, Hideki, Mizunaga, Takayuki, Hirokane, Masahiro, Ohta, Yuuki, Iwamoto, Akihisa
• Granted Patent: US 8,749,469 B2
• Time in Patent Office: Days
• US Class Current: 345/213
• CPC Class Codes: G09G 2300/043 Compensation electrodes or other additional electrodes in matrix displays related to distortions or compensation signals, e.g. for modifying TFT threshold voltage in column driver
• 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 2310/0286 Details of a shift registers arranged for use in a driving circuit
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/0219 Reducing feedthrough effects in active matrix panels, i.e. voltage changes on the scan electrode influencing the pixel voltage due to capacitive coupling
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3677 suitable for active matrices only

Abstract

A display device, in at least one embodiment, includes: a gate driver including a plurality of shift register stages each provided so as to correspond to each row, the gate driver outputting a gate signal for turning on switching elements in the each row; and a source driver outputting a data signal in accordance with an image to be displayed. For a row (first row) located at an outermost position from which scanning by use of the gate signal starts, a dummy line is provided. The dummy line is driven by a gate start pulse inputted into a shift register in the first row.

Claims

1. A display device comprising:

a display panel including;

scanning signal lines;

data signal lines;

pixel electrodes; and

switching elements,

each of the switching elements having (i) one terminal connected with one of the pixel electrodes and (ii) another terminal connected with one of the data signal lines,

each of the scanning signal lines turning on/off switching elements corresponding thereto,

the each scanning signal line forming one of rows together with the switching elements connected thereto, and pixel electrodes respectively connected to these switching elements,

a scanning signal line driving circuit including a plurality of shift registers each provided so as to correspond to each of the rows, the scanning signal line driving circuit outputting a scanning signal for turning on the switching elements in the each row;

a data signal line driving circuit outputting a data signal in accordance with an image to be displayed; and

a dummy scanning signal line provided for an outermost row located at an outermost position from which scanning by use of the scanning signal starts,

the dummy scanning signal line being driven by a gate start pulse inputted into a shift register corresponding to the outermost row located at the outermost position.

2. The display device according to claim 1, wherein:

the dummy scanning signal line is arranged so as to sandwich pixel electrodes in the outermost row between the dummy scanning signal line and a scanning signal line in the outermost row so that a distance between the dummy scanning signal line and the scanning signal line in the outermost row is equal to a distance between other two adjacent scanning signal lines, the outermost row located at the outermost position.

3. The display device according to claim 1, wherein:

the gate start pulse driving the dummy scanning signal line has a voltage level allowing the switching element to be turned on/off.

4. The display device according to claim 3, wherein:

the gate start pulse driving the dummy scanning signal line is set at the voltage level by a buffer.

5. The display device according to claim 4, further comprising:

a control device generating the gate start pulse and a clock for driving the scanning signal line driving circuit,

the control device including the buffer for generating the gate start pulse.

6. The display device according to claim 5, wherein:

the dummy scanning signal line is connected to a signal line connecting the control device with the scanning signal line driving circuit; and

the gate start pulse is inputted into the scanning signal line driving circuit and the dummy scanning signal line via the signal line.

7. A method for driving a display device including a display panel including:

scanning signal lines;

data signal lines;

pixel electrodes; and

switching elements,

each of the switching elements having (i) one terminal connected with one of the pixel electrodes and (ii) another terminal connected with one of the data signal lines,

each of the scanning signal lines turning on/off the switching elements corresponding thereto,

the each scanning signal line forming one of rows together with the switching elements connected thereto, and pixel electrodes respectively connected to these switching elements,

the method comprising the steps of;

driving the scanning signal line by outputting a scanning signal for turning on the switching elements in each of the rows;

driving a data signal line by outputting a data signal in accordance with an image to be displayed; and

driving, by use of a gate start pulse, a dummy scanning signal line provided for a row located at an outermost position from which scanning by use of the scanning signal starts, the gate start pulse being inputted into a shift register corresponding to the row located at the outermost position.