Apple patents electrical tests to find display defects before assembly
Apple has patented a method for testing display panels using built-in electrical circuits instead of just cameras. This system measures current flow to check for defects like dead pixels or signal issues before the screen is fully assembled.
In the filing’s own words
Systems and methods are provided for electrical testing to supplement or replace optical testing of an electronic display. Internal testing circuitry that includes analog front end (AFE) and analog-to-digital converter (ADC) circuitry may be included in the electronic display and may be used either alone or in combination with other testing devices to perform electrical characterization and defect screening. The electrical characterization and defect screening may be performed before or after self-emissive elements such as light-emitting diodes are installed, further improving yield. Types of electrical characterization and defect screening may include a partial passive mode electrical characterization of OLEDs, vertical or horizontal crosstalk measurement, scan line integrity testing, pixel bright dot testing, display pixel defect detection, and delayed defect detection for defects that may occur after some extended period of time (e.g., after several minutes, after several hours).
What exactly they claim (claim 1)
1. A system comprising: an electronic display comprising: an anode reset switch, wherein the anode reset switch is configured to couple anodes of self-emissive elements of selected display pixels to a test signal; and a source driver coupled to test circuitry, via a test bus, wherein the source driver is configured to supply the test signal; and a testing device configured to measure an aggregate current out of cathodes of the self-emissive elements of the selected display pixels that results due to the test signal to enable a current-voltage (IV) characterization of the self-emissive elements of the selected display pixels.
Facts
- Company
- Apple (Apple Inc.)
- Official title
- Electrical testing for panel characterization and defect screening
- Patent number
- US12768875B2
- Application number
- 18656567
- Filed
- May 6, 2024
- Granted
- Oct 20, 2026
- Inventors
- 7
- Claims
- 25
Classified under
G01R 31/2635 Physics & computingH10P 74/203 Electricity & electronicsMore from Apple in Chips & hardware
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Summaries are simplified from the filing’s own abstract and first claim. A patent filing is not a product announcement.
Patent data and drawings: U.S. Patent and Trademark Office (USPTO). Nebula is not affiliated with or endorsed by the USPTO.