EL DISPLAY APPARATUS

• US 20200135103A1
• Filed: 12/13/2019
• Published: 04/30/2020
• Est. Priority Date: 09/07/2001
• Status: Active Grant

• Current Assignee: JOLED Inc.
• Original Assignee: JOLED Inc.
• Inventors: TAKAHARA, Hiroshi, TSUGE, Hitoshi
• Granted Patent: US 10,699,639 B2
• Time in Patent Office: Days
• CPC Class Codes: G09G 2300/0404 Matrix technologies
• CPC Class Codes: G09G 2300/0413 Details of dummy pixels or dummy lines in flat panels
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2300/0814 used for selection purposes, e.g. logical AND for partial update
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0852 being a dynamic memory with more than one capacitor
• CPC Class Codes: G09G 2300/0861 with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
• CPC Class Codes: G09G 2310/0205 Simultaneous scanning of several lines in flat panels
• CPC Class Codes: G09G 2310/0218 with collection of electrodes in groups for n-dimensional addressing
• CPC Class Codes: G09G 2310/0248 Precharge or discharge of column electrodes before or after applying exact column voltages
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2310/0256 with the purpose of reversing the voltage across a light emitting or modulating element within a pixel
• CPC Class Codes: G09G 2310/027 Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters
• CPC Class Codes: G09G 2310/0289 Details of voltage level shifters 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 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• CPC Class Codes: G09G 2320/0257 Reduction of after-image effects
• CPC Class Codes: G09G 2320/0261 in the context of movement of objects on the screen or movement of the observer relative to the screen
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2320/06 : Adjustment of display parameters
• CPC Class Codes: G09G 2320/0606 : Manual adjustment
• CPC Class Codes: G09G 2320/0626 : for control of overall brightness
• CPC Class Codes: G09G 2320/0646 : Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2320/0653 : Controlling or limiting the speed of brightness adjustment of the illumination source
• CPC Class Codes: G09G 3/2003 : Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/2007 : Display of intermediate tones
• CPC Class Codes: G09G 3/32 : semiconductive, e.g. using light-emitting diodes [LED]
• CPC Class Codes: G09G 3/3233 : with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3241 : the current through the light-emitting element being set using a data current provided by the data driver, e.g. by using a two-transistor current mirror
• CPC Class Codes: G09G 3/325 : the data current flowing through the driving transistor during a setting phase, e.g. by using a switch for connecting the driving transistor to the data driver
• CPC Class Codes: G09G 3/3258 : with pixel circuitry controlling the voltage across the light-emitting element
• CPC Class Codes: G09G 3/3266 : Details of drivers for scan electrodes
• CPC Class Codes: G09G 3/3275 : Details of drivers for data electrodes
• CPC Class Codes: G09G 5/02 : characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: H01L 27/124 : with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 27/1251 : comprising TFTs having a different architecture, e.g. top- and bottom gate TFTs
• CPC Class Codes: H01L 27/1255 : integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 27/127 : with a particular formation, treatment or patterning of the active layer specially adapted to the circuit arrangement
• CPC Class Codes: H01L 27/156 : two-dimensional arrays
• CPC Class Codes: H01L 29/78645 : with multiple gate
• CPC Class Codes: H01L 29/78672 : Polycrystalline or microcrystalline silicon transistor
• CPC Class Codes: H01L 33/56 : Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/58 : Optical field-shaping elements
• CPC Class Codes: H05K 999/99 : dummy group
• CPC Class Codes: H10K 50/8428 : Vertical spacers, e.g. arranged between the sealing arrangement and the OLED
• CPC Class Codes: H10K 50/844 : Encapsulations
• CPC Class Codes: H10K 50/846 : comprising getter material or desiccants
• CPC Class Codes: H10K 50/86 : Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 59/12 : Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/1213 : the pixel elements being TFTs
• CPC Class Codes: H10K 59/1216 : the pixel elements being capacitors
• CPC Class Codes: H10K 59/126 : Shielding, e.g. light-blocking means over the TFTs
• CPC Class Codes: H10K 59/35 : comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 59/352 : the areas of the RGB subpixels being different

Abstract

An EL display apparatus is provided. A display screen includes pixels arranged in a matrix, with each pixel including an EL device and a pixel circuit. A source driver circuit is configured to output an analog video signal to each pixel. A gate driver circuit is on at least one side of the display screen, with the gate driver circuit including first and second gate driver circuits. Each pixel includes a driving transistor, a first switch transistor, and a second switch transistor. A gate terminal of the first switch transistor is connected to a first gate signal line of the first gate driver circuit, and a gate terminal of the second switch transistor is connected to a second gate signal line of the second gate driver circuit. The first and second switch transistors are on/off controlled, independently, by the first and second gate driver circuits.

Claims

1. An electroluminescent (EL) display apparatus, comprising:

a display screen including pixels arranged in a matrix, each of the pixels including an EL device and a pixel circuit;

a source driver circuit configured to output analog video signals to the pixels;

a plurality of source signal lines through which the analog video signals output from the source driver circuit are transmitted;

a gate driver circuit on at least one side of the display screen, the gate driver circuit including a first gate driver circuit and a second gate driver circuit;

a plurality of first gate signal lines through which a first selection voltage or a first non-selection voltage output from the first gate driver circuit is transmitted; and

a plurality of second gate signal lines through which a second selection voltage or a second non-selection voltage output from the second gate driver circuit is transmitted,

wherein the pixel circuit of each of the pixels includes;

a driving transistor configured to provide a current to the EL device;

a first switch transistor provided on a current path through which the current is provided from a power line through the driving transistor to the EL device; and

a second switch transistor to supply, to the driving transistor, an analog video signal from one of the plurality of source signal lines,

a gate terminal of the first switch transistor is connected to one of the plurality of first gate signal lines,

a gate terminal of the second switch transistor is connected to one of the plurality of second gate signal lines,

the first switch transistor and the second switch transistor are on/off controlled, independently, by the first gate driver circuit and the second gate driver circuit, the first switch transistor being controlled by the first gate driver circuit based on the first selection voltage and the first non-selection voltage, the second switch transistor being controlled by the second gate driver based on the second selection voltage and the second non-selection voltage,

the source driver circuit is a semiconductor chip and is attached to the EL display apparatus, and

an output terminal of the source driver circuit is connected to one of the plurality of source signal lines.

2. The EL display apparatus according to claim 1,

wherein the pixels arranged in the matrix on the display screen include a first pixel for a first color and a second pixel for a second color, and

an area of a pixel electrode of the first pixel and an area of a pixel electrode of the second pixel are different.

3. The EL display apparatus according to claim 1,

wherein the first gate driver circuit is configured to turn the first switch transistor of each of the pixels on and off to generate a band-shaped non-display region and a band-shaped display region on the display screen and to move the band-shaped non-display region and the band-shaped display region relative to the display screen.

4. The EL display apparatus according to claim 1,

wherein the first gate driver circuit is configured to turn the first switch transistor of each of the pixels on and off to simultaneously generate a plurality of band-shaped non-display regions and a plurality of band-shaped display regions on the display screen and to move the plurality of band-shaped non-display regions and the plurality of band-shaped display regions relative to the display screen.

5. The EL display apparatus according to claim 4,

wherein the plurality of band-shaped non-display regions is spaced apart on the display screen, and

the plurality of band-shaped display regions is spaced apart on the display screen.

6. The EL display apparatus according to claim 4,

wherein the first gate driver circuit is configured to change a duty ratio of an area of one non-display region on the display screen to an area of one display region on the display screen depending on a brightness adjustment.

7. The EL display apparatus according to claim 1,

wherein the plurality of first gate signal lines is divided into a plurality of blocks, and first gate signal lines in one block are connected as one control line.

8. The EL display apparatus according to claim 1,

wherein the pixel circuit of each of the pixels further includes a third switch transistor,

a first terminal of the third switch transistor is connected to a gate terminal of the driving transistor,

a second terminal of the third switch transistor is connected to a terminal of the driving transistor other than the gate terminal of the driving transistor, and

a gate terminal of the third switch transistor is connected to one of the plurality of second gate signal lines.

9. The EL display apparatus according to claim 8,

wherein the third switching transistor has a multi-gate structure.

10. The EL display apparatus according to claim 8,

wherein the gate terminal of the second switch transistor and the gate terminal of the third switch transistor are connected to the second gate driver circuit, and the second gate driver circuit includes a second gate signal line connected to both the gate terminal of the second switch transistor of a N^th row and the gate terminal of the third switch transistor of a (N+1)^th row.

11. The EL display apparatus according to claim 1,

wherein the pixel circuit of each of the pixels further includes a third switch transistor,

the third switch transistor is between a pixel electrode of the respective pixel and a voltage line.

12. The EL display apparatus according to claim 11,

wherein the pixel electrode of the respective pixel is an anode terminal of the EL device, and the voltage line is configured to supply a reverse bias voltage for reverse biasing the anode terminal of the EL device.

13. The EL display apparatus according to claim 1,

wherein the gate driver circuit is configured to receive a control signal that is level-shifted by the source driver circuit.

14. The EL display apparatus according to claim 1,

wherein each of the pixels further includes an encapsulating film that seals the EL device.

15. An electronic device, comprising:

an EL display apparatus according to claim 1.