Frank Rosenblatt was an American psychologist notable in the field of artificial intelligence. He is sometimes called the father of deep learning for his pioneering work on artificial neural networks.
An elementary Rosenblatt's perceptron. A-units are linear threshold element with fixed input weights. R-unit is also a linear threshold element but with ability to learn according to Rosenblatt's learning rule. Redrawn in from the original Rosenblatt's book.