Fig. 1. （a）Structure diagram of OLED；（b）Schematic diagram of OLED screen current trend；（c）Magnetic field distribution of lighting single line at different heights.

Fig. 2. Schematic diagram of TMR and its amplification circuit

Fig. 3. Structure of OLED screen measurement system

Fig. 4. （a）OLED screen when two consecutive lines are lit，lighting up line 22，23；（b）Driving IC logic of two lines of OLEDs lit continuously；（c）Signals of two lines lit continuously.

Fig. 5. （a）Turn on the OLED screen with multiple lines at intervals，and turn on the 16th，18th，19th，22nd，23rd，24th，28th，29th，30th，31st lines；（b）Test results with multiple lines lit at intervals；（c）Turn on the single column OLED screen and turn on the 22nd column；（d）Turn on the test results of a single column.

Fig. 6. OLED current-magnetic field-brightness mapping