Apparatus and method for detecting faults in outdoor display
AssigneeBong Oh Electronics Ind. Co., Ltd.
InventorChul Yong Kim
Life of this patent
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Abstract
The present invention is to provide an apparatus for detecting errors due to cutoff of a unit pixel and short between the unit pixel and the ground voltage level in a lighting-off state, and also a method for checking in a real time whether information data outputted from a remote host computer is normally represented on a display and detecting all the errors due to cutoff of a unit pixel, short between a unit pixel and the ground voltage level, and short between unit pixels.
Claims14
In an outdoor display having a plurality of unit pixels, wherein each of the unit pixels is driven by a driving means in response to a control signal inputted from an external circuit and has a plurality of light emitting devices which are coupled in series to each other, and wherein the light emitting devices have leakage current in a lighting-off state, a fault detection circuit comprising:
- a current path coupled in parallel to the driving means so that the leakage current flows on the current path in the lighting-off state;
- and
- a current sensing means for sensing the leakage current on the current path in the lighting-off state,
- whereby the fault detection circuit determines that the unit pixel is cut off when any leakage current is not sensed by the current sensing means.
A fault detection circuit in an electric apparatus having a plurality of element groups to be driven by a driving means in response to a control signal inputted from an external circuit, wherein elements in each of the element groups are electrically connected in series to each other and the element groups are electrically connected in parallel to each other, wherein cutoff of one of elements causes the others to be cut off, and wherein the elements has leakage current in an off-state, the fault detection circuit comprising:
- a leakage current detecting means for detecting, in the off-state, an cutoff error which is caused by the element groups in the electric apparatus;
- and
- a monitoring means for detecting a short error between each element group and a ground voltage level, wherein the monitoring means considers the monitored element group as an error group when the monitored element group operates without an input of the control signal.
A fault detection method in a display having a plurality of unit pixels, comprising the steps of:
- (a) receiving a display check request signal from a controlling means;
- (b) detecting errors due to cutoff of a unit pixel and short between the unit pixel and a ground voltage level in a lighting-off state, if the received request signal is a request signal for individual dot check;
- and
- (c) comparing desired display information data with actually displayed data in the lighting-on state and checking whether errors occur and then detecting all dots through an individual dot check in the lighting-off state, if the received request signal is a request signal for displayed content check.
Dependencies are inferred from the claim text.