Display device and the driving method of the same

• US 20060066533A1
• Filed: 09/14/2005
• Published: 03/30/2006
• Est. Priority Date: 09/27/2004
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Inventors: Akimoto, Hajime, Kasai, Naruhiko, Sato, Toshihiro, Tokuda, Naoki
• Granted Patent: US 7,773,080 B2
• Time in Patent Office: Days
• 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 2320/029 by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element

Abstract

A plurality of organic EL elements which are arranged on a display panel lowers the brightness along with a lapse of light emitting time and hence, the power consumption is increased to maintain the brightness. However, the increase of the power consumption shortens a lifetime of the organic EL elements. To overcome this drawback, a power supply circuit which drives the display panel has a function of controlling an electric power supplied to the display panel to a fixed value or less in response to a detection signal from a detection part which detects a cathode current of the organic EL elements.

Claims

1. A display device comprising:

a display panel on which a plurality of self-luminous light emitting elements are arranged;

a control circuit which controls the display panel;

a signal processing circuit which inputs an image signal to the display panel in response to a control signal from the control circuit; and

a power supply circuit which supplies an electric power to the display panel, wherein

the power supply circuit restricts the electric power supplied to the display panel to a fixed value or less in response to a detection signal from a detection part which detects the power consumption of the display panel.

2. A display device according to claim 1, wherein the self-luminous light emitting elements are formed of an organic EL element and the detection part detects a cathode current of the organic EL element.

3. A display device according to claim 1, wherein the self-luminous light emitting elements are formed of an organic EL element and the detection part detects an anode current of the organic EL element.

4. A display device according to claim 1, wherein the self-luminous light emitting elements are formed of an organic EL element and the detection part detects either one or both of a cathode current and an anode current of the organic EL element, and the detection part is arranged inside the display panel or inside the power supply circuit.

5. A display device comprising:

a display panel on which a plurality of self-luminous light emitting elements are arranged;

a control circuit which controls the display panel;

a signal processing circuit which inputs an image signal to the display panel in response to a control signal from the control circuit; and

a power supply circuit which supplies an electric power to the display panel, wherein

the power supply circuit restricts the electric power supplied to the display panel to a fixed value or less in response to a detection signal from a detection part which detects a brightness level of the image signal.

6. A display device according to claim 5, wherein the image signal is formed of an image signal which is inputted to the signal processing circuit.

7. A display device comprising:

a display panel on which a plurality of self-luminous light emitting elements are arranged;

a control circuit which controls the display panel;

a signal processing circuit which inputs an image signal to the display panel in response to a control signal from the control circuit; and

a power supply circuit which supplies an electric power to the display panel, wherein

the power supply circuit and the signal processing circuit restrict the electric power supplied to the display panel to a fixed value or less in response to a detection signal from a detection part which detects the power consumption of the display panel.

8. A display device comprising:

a display panel on which a plurality of self-luminous light emitting elements are arranged;

a control circuit which controls the display panel;

a signal processing circuit which inputs an image signal to the display panel in response to a control signal from the control circuit; and

a power supply circuit which supplies an electric power to the display panel, wherein

the power supply circuit restricts the electric power supplied to the display panel to a fixed value or less in response to a detection signal from a power restricting circuit which restricts the power consumption of the display panel.

9. A display method comprising the steps of:

supplying an electric power to a display panel from a power supply circuit; and

displaying an image on the display panel in response to an image signal from a signal processing circuit and a control signal from a control circuit, wherein

the power supply circuit restricts an electric power supplied to the display panel to a fixed value or less in response to a detection signal from a detection part which detects the power consumption of the display panel.