Drive circuit for light emitting elements

A technology of light-emitting components and driving circuits, applied in the direction of circuits, electrical components, electroluminescent light sources, etc.

Inactive Publication Date: 2004-12-15
PIONEER CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to this non-uniformity in the driving current of the organic EL among the cells, patterns of non-uniform brightness may appear on the display screen

Method used

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  • Drive circuit for light emitting elements
  • Drive circuit for light emitting elements
  • Drive circuit for light emitting elements

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0014] refer to figure 2 , shows a circuit diagram of an organic EL light-emitting element driving circuit according to an embodiment of the present invention.

[0015] refer to figure 2 The configuration of this embodiment will be described. In this drawing, the switching element Q1 (10) is a switching element whose ON / OFF state is controlled by a selection signal sent through an address line of the display panel. The switching element Q1 ( 10 ) can be formed of, for example, a bipolar transistor or FET. In the switching element Q1 (10), a gate terminal for controlling the ON / OFF state of the switching element is connected to an address line. One terminal of this switching element is connected to a data line of the display panel, and the other terminal is connected to a capacitor C1 ( 20 ) which will be described later. The capacitor C1 (20) stores the data of the data line (ie, the potential of the data line) obtained through the switching element Q1 (10). One terminal ...

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PUM

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Abstract

A display panel includes a number of light emitting elements arranged in a matrix fashion. A light emitting element driving circuit for use in the display panel can reduce fluctuations in brightness among the light emitting elements. A pulse supply circuit is formed so as to charge / discharge a capacitor based on a clock signal and drive the light emitting element based on the resulting discharge current. The amplitude of a drive current for each of the light emitting elements is not controlled by a transistor in a TFT circuitry, but controlled by external factors installed outside the display panel. The external factors may be a pulse supply circuit providing drive power source voltage and clock frequency. The external factors can be determined precisely.

Description

technical field [0001] The present invention relates to a driving circuit for light-emitting elements arranged in an array in an image display panel. Background technique [0002] When light-emitting elements such as organic electroluminescent materials (hereinafter referred to as "organic EL") are arranged in an array in a display panel, a TFT (thin film transistor) driving circuit shown in Figure 1 of the accompanying drawings is usually used as a driving display A driver circuit for each pixel (each light-emitting unit) of the board. In Fig. 1, the units are represented by dotted boxes. [0003] In FIG. 1, reference symbol Qa denotes a switching transistor for addressing, C denotes a storage capacitor that stores (holds) a voltage level of data, and Qb denotes a driving transistor that drives a load (ie, an organic EL light emitting element). Reference symbol EL denotes an organic EL light emitting element. The light-emitting element EL has a structure in which a light...

Claims

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Application Information

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IPC IPC(8): H01L51/50G09GG09G3/20G09G3/30G09G3/32H05B33/14
CPCG09G3/3258G09G2320/043G09G2300/0809G09G2310/0251G09G2300/0819G09G2300/0876G09G3/30
Inventor奥田义行
OwnerPIONEER CORP