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LED Image display, driving circuit device and fault detecting method

An image display device, light-emitting diode technology, applied in circuits, image communication, television, etc., can solve problems such as difficulty in judging faults, a lot of work, LED difficulties, etc.

Inactive Publication Date: 2004-10-13
SONY CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in the case of a large-scale LED display used for the purpose, it is difficult to point out faulty LEDs based on brightness at the time of shipment testing due to the large number of LEDs
In addition, after being installed in the place of use, when replacing the faulty LED, it is necessary to judge whether the brightness is good or not, for example, under the condition of direct sunlight, so there are some situations where it is difficult to judge the fault in such a use environment.
Also, when installed in a higher position, replacing a failed LED requires a lot of work and high maintenance costs

Method used

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  • LED Image display, driving circuit device and fault detecting method
  • LED Image display, driving circuit device and fault detecting method
  • LED Image display, driving circuit device and fault detecting method

Examples

Experimental program
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no. 1 example

[0031] figure 1 is the current-voltage characteristic graph between the LED terminals.

[0032] When using the LED display ( figure 1 (a) part), the current in the LED is about 1mA to 80mA. In this operating region, the change in voltage is small relative to the change in current. On the other hand, in the cut-off region of the forward voltage Vf or less than the forward voltage Vf ( figure 1 (b) part), the change in voltage is large relative to the change in current. Thus, as a result, a constant current flows through the LED and the detection sensitivity can be improved in the cut-off region. In this embodiment, based on the voltage difference detected between the terminals, the voltage between the LED terminals in the cut-off region is detected to determine that the LED is in a fault state close to short circuit or electrical connection disconnection, or in A quasi-fault condition that is likely to cause a short circuit or disconnection of electrical connections.

[0...

no. 2 example

[0044] In the second embodiment, the case where the fault detection method shown in the first embodiment is applied to the LED display for transmitting luminescent data in the token transfer method of the serial passing mode is described.

[0045] FIG. 5 is a schematic view of an LED arrangement on an image display panel. Similarly, Figure 6 is a block diagram of the connection relationship between the LED driver IC and the controller.

[0046] On the image display panel 20 shown in FIG. 5 , unit pixels 21i_k (i=1, 2, . . . , m; k =1, 2, ..., n) are arranged in m rows by n columns. Here, the red LED is represented by DRi_k, the green LED is represented by DGi_k, and the blue LED is represented by DBi_k.

[0047] A driver IC for driving these LEDs constitutes one embodiment of the "driving circuit device" of the present invention, and one driver IC is provided for each color LED in a group of predetermined number of unit pixels. In the example shown in FIG. 6 , in one row, d...

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PUM

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Abstract

A defect detection of light-emitting diodes (LEDs) is electrically performed on a large-scale display, comprising a plurality of light-emitting diodes arranged by a predetermined arrangement on an image display face, voltage detection portions for applying a constant current to a plurality of light-emitting diodes in an off region at a forward voltage or less in accordance with an input of a signal indicating a defect detection mode and detecting voltages between terminals of light-emitting diodes arising when the constant current flows there through, and a defect detection portion for electrically detecting a defect from the plurality of light-emitting diodes based on detection results of the voltage detection portion; and drive circuit devices (driver ICs) having the above configuration are serially connected and an electric signal indicating a result of defect detection is output from its final stage.

Description

technical field [0001] The present invention relates to an image display device having a function of detecting failure in a plurality of light emitting diodes, and to a driving circuit device such as a driver IC and a method for detecting failure of light emitting diodes. Background technique [0002] In various indoor and outdoor event venues, indoor and outdoor stadiums and other sports facilities, image display devices for video and information (hereinafter referred to as LED displays) using LEDs as display elements are used to display live sports Rebroadcasts, live television broadcasts and commercials. In LED displays, the display elements are composed of unit pixels in m rows by n columns. Black and white displays and color displays exist. In the case of a color display, a unit pixel consists of three LEDs: red (R), green (G), blue (B). [0003] The LED displays used for the different applications described are usually bulky and placed in high positions. [0004] B...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04N5/66G01N27/72G01N27/82G01R33/12G09G3/00G09G3/04G09G3/14G09G3/20G09G3/32H01L33/00
CPCG09G3/2088G09G3/32G09G3/2085G09G3/006G09G2330/12
Inventor 矢野元康高木祐一小松祯浩铃木满川濑正隆
Owner SONY CORP