[HLK touch screen test fail] Changes in display refresh rate affect touch performance

Question

HLK test fail occurs because the display refresh rate changes with the PSR(Panel Self Refresh) function.

In the "PSR on" state, the PC operates at a low refresh rate (30Hz) when there is no screen update, and when a screen update occurs by touch, the PC operates at the original refresh rate (120Hz).

In this state, when I perform the HLK test, Tap touch test and Reporting rate test, a scan time error occurs because the touch report interval between the first touch and the next touch is farther than 16.6ms.

**Questions

In the HLK test, does touch performance have to be satisfied even when the refresh rate changes like the PSR function?

Or when performing the HLK test, should I turn off the PSR function which affects touch performance?

I would appreciate it if you could respond to this matter.

Thank you!

Answer 1

Hello,

Thank you for posting in Q&A forum.

In theory, the hardware should be able to meet the specified touch performance standards in HLK tests regardless of how the display refresh rate changes. This is because real-world use covers operations at a variety of refresh rates, and the device should be able to respond to user input reliably and in a timely manner.

Given your situation, in order to accurately evaluate the performance of the touch screen without being affected by the dynamic adjustment of the refresh rate by the PSR function, it is recommended to temporarily disable the PSR function when performing HLK tests. This can isolate the unstable factors that may be introduced by the PSR function, thereby more accurately evaluating touch performance.

I hope the information above is helpful.

Best Regards,

Yanhong Liu

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