US 6,583,775 B1Granted

Image display apparatus

AssigneeSony Corporation

InventorsMitsunobu Sekiya, Akira Yumoto

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Abstract

The invention provides an image display apparatus which increases the degree of freedom in designing of an active element of a pixel to allow good designing and can adjust the display brightness freely and simply. Each pixel includes a light emitting element (OLED) with a brightness value which varies depending upon an amount of current supplied thereto, a first TFT controlled by a scanning line for writing brightness information given thereto from a data line into the pixel, and a second TFT for controlling the amount of current to be supplied to the OLED corresponding to the brightness information written. Writing of the brightness information into each pixel is performed by applying an electric signal corresponding to the brightness information to the data line while the scanning line is selected. The brightness information written in each pixel is held by the pixel also after the scanning line is placed into a non-selected state so that the OLED can continue lighting with a brightness value corresponding to the brightness information held by the pixel. A stopping control line compulsorily extinguishes the OLEDs of the pixels connected to the same scanning line at least in a unit of a scanning line so that the OLEDs are placed into an extinguished state from a lit state within a period of one scanning cycle after the brightness information is written into the pixels until new brightness information is written into the pixels subsequently.

Claims26

Dependent claims

An image display apparatus, comprising:

a plurality of pixels arranged in a matrix;
a plurality of scanning lines for selecting said pixels in a predetermined scanning cycle;
a plurality of data lines extending perpendicularly to said scanning lines for providing brightness information to drive said pixels;
said pixels being disposed at intersecting points of said scanning lines and said data lines;
each of said pixels including a light emitting element for emitting light with a brightness value which varies depending upon an amount of current supplied thereto, a first active element controlled by one of said scanning lines for writing the brightness information given thereto from one of said data lines into the pixel connected to said data line while the scanning line connected to said pixel is selected, a second active element for controlling the amount of current to be supplied to the light emitting element in response to the brightness information written in the pixel;
and means for holding the brightness information written in each of said pixels also after the scanning line connected to the pixel is placed into a non-selected state so that the light emitting element of the pixel can continue lighting with a brightness value corresponding to the brightness information held by the pixel characterized in that it further comprises control means for compulsorily extinguishing the light emitting elements of those of said pixels which are connected to a same one of said scanning lines in at least one scanning line so that the light emitting elements are placed into an extinguished state from a lit state within a period of one scanning cycle corresponding to the period between the writing of the brightness information into said pixels and the writing of new brightness information into said pixels subsequently, thereby controlling temporal average brightness of the light emitting elements.

3 more elements

A driving method for an image display apparatus which includes a plurality of pixels arranged in a matrix, a plurality of scanning lines for selecting said pixels in a predetermined scanning cycle, and a plurality of data lines extending perpendicularly to said scanning lines for providing brightness information to drive said pixels and wherein said pixels are disposed at intersecting points of said scanning lines and said data lines and each of said pixels including a light emitting element for emitting light with a brightness value which varies depending upon an amount of current supplied thereto, a first active element controlled by one of said scanning lines for writing the brightness information given thereto from one of said data lines into the pixel, and a second active element for controlling the amount of current to be supplied to the light emitting element in response to the brightness information written in the pixel, comprising the steps of

writing brightness information into each of said pixels by applying an electric signal corresponding to the brightness information to the data line connected to the pixel while the scanning line connected to the pixel is selected, the brightness information written in each of said pixels being held by the pixel also after the scanning line connected to the pixel is placed into a non-selected state so that the light emitting element of the pixel can continue lighting with a brightness value corresponding to the brightness information held by the pixel, characterized in that it further comprises the step of compulsorily extinguishing the light emitting elements of those of said pixels which are connected to a same one of said scanning lines in at least one scanning line so that the light emitting elements are placed into an extinguished state from a lit state within a period of one scanning cycle, corresponding to the period between the writing of the brightness information into said pixels and the writing of new brightness information into said pixels subsequently, thereby controlling temporal average brightness of the light emitting elements.

Dependencies are inferred from the claim text.

Facts

Application: 09/594,087Filed 15 Jun 2000
Priority: JP 11-17057717 Jun 1999
Granted: 24 Jun 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification13 codes

G09G 3/2081
By a combination of two or more gradation control methods: with combination of amplitude modulation and time modulation
G09G 3/30
Using controlled light sources: using electroluminescent panels
G09G 3/3233
Using an active matrix: with pixel circuitry controlling the current through the light-emitting element
G09G 3/3266
Organic, e.g. using organic light-emitting diodes [OLED]: details of drivers for scan electrodes