I'm not going to spend too long on my critique of frame-locks and button-locks - just enough so you understand why I felt there was a better answer.
Why I Don't Like Frame-Lock (and Liner-Lock) Knives
#1 - Having to maneuver my fingers to close the blade. I've opened and closed frame-locks tens of thousands of times (maybe more) - I'm proficient enough in using them. I love how it feels to flip them open ...but really don't like how feels to close them. It's clunky.
#2 - I've always disliked the side-pressure on the blade. This only happen in the closed position - but that's the position it's most of the time. Good knifemakers will have perfect centering - but the pressure is still there. From a mechanical perspective I'm not a fan.
#3 - As a maker there are a lot of things to make work together. The detent ball position (closed and open), the detent ball hole depth, the stop pin position (open and closed), lock-up, centering, bearing pressure, and a few other things depending on the knife. It's impressive that good knifemakers get all these things dialed-in together to make a great knife - they have my absolute admiration.
In saying that... I've always felt it doesn't need to be that complicated. As a knife maker that's a lot of variables to get right ...and, as a knife user, that's a lot of variables that can go wrong.
#4 - As a maker, if you come up with a new knife design, then you have to essentially start from the beginning in getting everything I mentioned in #3 dialed-in again. Most definitely not a fan of this.
Why I Don't Like Button-Lock Knives
#1 - Similar to frame-locks... there is a decent amount of re-designing and re-tuning if you come up with a new knife design.
#2 - The button is aesthetically not good - it's like an afterthought that has function only. Yes, I know, it sounds like I'm splitting hairs here and picking on a minor thing. That may be true for most - but, as a designer, these "little things" are EVERYTHING.
Before we move on...
I don't want to end on a negative note with regards to the above locking mechanisms. They are good locks. They are tried-and-tested. They are safe. They are secure. They are functionally good.
I feel the button-lock is the better solution of the two (if I had to pick one).
Hopefully what I've said above explains to you why I couldn't help but design my own knife lock. Now let's finally get into the real meat-and-potatoes...