Hello Frank,
Thank you for your question and the pictures of your Japanese maple.  
Although I cannot see details from the pics of the single leaf and the full tree, what I do see appears to be a nice healthy Japanese maple tree over all.
I highly suspect that your lovely tree suffers from scorch every year, as that is one of the few maladies that they are prone to.  This year's wild weather swings have sure made proper watering a real challenge.
I am sharing a couple links about Japanese maples that should help you.

Leaf scorch cause & fix
https://durhammastergardeners.com/2017/06/27/japanese-maple-leaf-scorch-by-jane-malec-emgv/

General information on care of JM
https://extension.unh.edu/blog/2019/08/how-should-i-plant-care-japanese-maple

I hope this helps you to prevent leaf scorch in the future.  Sadly, the damaged leaves will not get better, but a change in watering techniques and frequency will help new growth avoid the scorch problem.

Thank you again for using the Ask Extension online service.

Happy Summer!