Unlock instant, AI-driven research and patent intelligence for your innovation.

Electric current supply circuit and display device with the same circuit

A display device and current technology, applied in circuits, electrical components, electronic switches, etc., can solve the problems of inability to maintain the consistency of pixel display brightness characteristics, discontinuous changes in drain voltage, transient fluctuations in data current, etc. The effect of uniform display quality and display characteristics

Inactive Publication Date: 2004-01-21
MITSUBISHI ELECTRIC CORP
View PDF0 Cites 10 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0022] Specifically, in the current supply circuit shown in FIG. 12, the transistor characteristics (in particular, the threshold voltage or the mobility) of the n-type TFT element T6 that drives the data current Idat vary, and cannot correspond to the data voltage Vdat of the same level in each case. When the same data current Idat is generated in the current supply circuit, the uniformity of display luminance characteristics between pixels cannot be maintained
[0023] In the conventional current supply circuit shown in FIG. 12, at the moment when the data line DL is connected to the current supply circuit in response to the activation (H level) of the control signal Vscn, since the drain voltage of the n-type TFT element T6 does not Changes continuously, so there is a problem with transient fluctuations in data current

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Electric current supply circuit and display device with the same circuit
  • Electric current supply circuit and display device with the same circuit
  • Electric current supply circuit and display device with the same circuit

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0043] Referring to FIG. 1 , an EL display device 1 of the present invention includes an EL display portion 2 . A plurality of pixels 5 are arranged in a matrix on the EL display unit 2 . In the EL display unit 2 for color display, three adjacent pixels 5 form one display unit 6 . That is, each display unit 6 is constituted by three pixels 5 that respectively display red (R), green (G) and blue (B).

[0044] Scanning lines SL are arranged corresponding to rows of pixels (hereinafter referred to as lines) respectively, and data lines are respectively arranged corresponding to columns of pixels (hereinafter referred to as pixel columns). In Fig. 1, the display unit of the mth column and the (m+1)th column in the nth row (n is a natural number) and the (n+1)th row and the corresponding scanning line SL ( n), SL(n+1), data lines DL-R(m) corresponding to red (R) display pixels, DL-R(m+1), data lines DL-R corresponding to green (G) display pixels G (m), DL- G (m+1), data lines D...

Embodiment 2

[0098] In Embodiment 2, a configuration in which the polarity of the TFT element is changed as a modification of the configuration according to Embodiment 1 will be described.

[0099] Figure 6 is a circuit diagram showing the configuration of the current supply circuit according to Embodiment 2, Figure 6 The data current supply unit 10# corresponding to the m-th column is representatively shown in .

[0100] refer to Figure 6 , the data current supply section 10# according to Embodiment 2 includes current supply circuits 10#a and 10#b set to complementary different operation modes. Current supply circuit 10#a has p-type TFT elements T20a to T25a, transfer capacitor C21a, voltage holding capacitors C22a, C23a, and logic gates NOT21a, NAND1a, and NAND2a. Current supply circuit 10#b has the same structure as current supply circuit 10#a, including p-type TFT elements T20b-T25b, transfer capacitor C21b, voltage holding capacitors C22b, C23b, logic gates NOT21b, NAND1b, NAND2...

Embodiment 3

[0119] In the third embodiment, a configuration in which the display characteristics of the pixels are further uniformed by setting the reference current Iref used by the data current supply unit 10 in the compensation mode more finely will be described.

[0120] refer to Figure 8 , in the display device 1# according to Embodiment 3, compared with the structure of Embodiment 1 shown in FIG. 1 , the difference lies in that it is used to adjust the The reference current adjustment circuit 30 for the reference current Iref replaces the reference current supply circuits 12R, 12G, and 12B.

[0121] refer to Figure 9 , The reference current adjustment circuit 30 has: a selection circuit 35 for selecting according to the data current setting value; current generation circuits 36a-36d for generating constant currents Ir1-Ir4 of different levels respectively; respectively arranged in the current generation circuit 36 a to 36 d and the switches 38 a to 38 d between the reference cur...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The current supply circuit 10a for supplying a data current corresponding to display brightness to a current driving type light emitting element allows a reference current Iref to pass through a driving transistor T11a for supplying a data current Idat to a data line DL in a supply mode at the time of a compensation mode which is performed before the supply mode. The voltage of a node N2(a) connected to the gate of the driving transistor T11a is held by a voltage holding capacitor C2a. In the supply mode, the voltage of the node N2(a) is changed in accordance with a data signal Vdat. Data voltage Vdat is set in accordance with a difference between the data current Idat to be supplied and the reference current Iref.

Description

technical field [0001] The present invention relates to a current supply circuit, and more particularly, to a current supply circuit for supplying a current corresponding to an instructed display brightness to a current-driven light-emitting element, and an electroluminescence (EL) display device including the same. Background technique [0002] In recent years, organic EL display devices have attracted attention in the field of flat panel displays typically using liquid crystal displays. Compared with liquid crystal displays, organic EL display devices have advantages of high contrast ratio, fast response speed, and wide viewing angle. In an organic EL display device, an organic EL element that is a current-driven light-emitting element is disposed on each pixel. An organic light emitting diode is known as a typical example of an organic EL element. [0003] Especially recently, among such organic EL display devices, low-temperature polysilicon type TFT displays using low...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): H01L51/50G09G3/20G09G3/30G09G3/32H03K17/687
CPCG09G2320/0295G09G2300/0842G09G2300/0814G09G2320/043G09G3/325G09G3/3283G09G2320/0233
Inventor 時岡秀忠桥户隆一浦壁隆浩上里将文岡部正志井上满夫
Owner MITSUBISHI ELECTRIC CORP