Display device

• US 6,653,996 B2
• Filed: 03/28/2001
• Issued: 11/25/2003
• Est. Priority Date: 03/28/2000
• Status: Expired due to Term

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Komiya, Naoaki
• Primary Examiner(s): Hjerpe, Richard
• Assistant Examiner(s): ZAMANI, ALI A
• Application Number:
  US09/819,880
• Publication Number:
  US 20020011973A1
• Time in Patent Office: 972 Days
• Field of Search: 345/76, 345/82, 345/83, 345/211, 345/212, 345/77, 345/204, 345/214, 345/92, 713/324, 713/330, 713/340, 315/169.3
• US Class Current: 345/76
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2320/046 Dealing with screen burn-in prevention or compensation of the effects thereof
• CPC Class Codes: G09G 2330/02 Details of power systems and of start or stop of display operation
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays

Abstract

In a display device including, for each pixel, an organic EL element (60) and TFTs (30, 40) for controlling the element, a sequential circuit (350) is provided for stopping supply of power source voltages Vvdd and Hvdd to drivers (80, 90) for driving the TFTs (30, 40) which control each organic EL element (60) after stopping supply of power source voltage Pvdd to the organic EL element (60) when the device is turned off.

Claims

1. A display device, comprising:

a vertical driver for supplying a scan signal to a plurality of gate signal lines;

a horizontal driver for supplying a data signal to a plurality of data signal lines crossing said plurality of gate signal lines;

a switching element connected to the gate signal line and the data signal line at an intersection between these signal lines;

an emissive element connected to said switching element;

an element driving power source line for supplying electric power to said emissive element; and

a sequence circuit for stopping supply of electric power to said element driving power source line before stopping supply of a driver driving power source.

2. The display device according to claim 1, wherein said sequence circuit includes first and second transistors, first and second resistors, and a third resistor connecting said first and second transistors;

said first transistor has an emitter connected to said first resistor which is connected to an element driving power source generation circuit, a base connected to a power source, and a collector connected to ground; and

said second transistor has an emitter connected to said second resistor which is connected to a driver driving power source generation circuit, a base connected to said third resistor, which is connected to the emitter of said first transistor, and to the other electrode of a capacitor whose one electrode is connected to ground, and a collector connected to ground.

3. The display device according claim 1, wherein said emissive element is an electroluminescence element.

4. A display device, comprising:

a vertical driver for supplying a scan signal to a plurality of gate signal lines;

a horizontal driver for supplying a data signal to a plurality of data signal lines crossing said plurality of gate signal lines;

an emissive element;

an element driving power source line for supplying power to said emissive element;

a switching element disposed between the gate and data signal lines and a corresponding emissive element in proximity of an intersection between these signal lines, said switching element having a first thin film transistor and a second thin film transistor, the first thin film transistor having a first region of an active layer connected to said data signal line, a gate connected to said gate signal line, and a second region of the active layer connected to a gate of the second thin film transistor, and the second thin film transistor having a first region of an active layer connected to said element driving power source line, and a second region of the active layer connected to one electrode of said emissive element; and

a sequence circuit for stopping supply of electric power to said element driving power source line before stopping supply of a driver driving power source.

5. The display device according to claim 4, wherein said sequence circuit includes first and second transistors, first and second resistors, and a third resistor connecting said first and second transistors;

said first transistor has an emitter connected to said first resistor which is connected to an element driving power source generation circuit, a base connected to a power source, and a collector connected to ground; and

said second transistor has an emitter connected to said second resistor which is connected to a driver driving power source generation circuit, a base connected to said third resistor, which is connected to the emitter of said first transistor, and to the other electrode of a capacitor whose one electrode is connected to ground, and a collector connected to ground.

6. The display device according claim 4, wherein said emissive element is an electroluminescence element.