I am an intellectual property attorney. As other have mentioned furniture (and lamp) designs are usually best suited for design patent protection. A design patent lasts 14 years. If the claimed design is very particular it may be easy to design around. There is an art to drafting strong design patents. Part of iit is knowing what should be included in the design and what should be shown in broken lines, indicating that that portion forms no part of the claimed design.

From a design point of view there are a lot of differences between your lamps. His shade is octagonal while yours is square, his column is mostly square while yours is a "+" and your bases are different. Not knowing whether he has a design patent or not makes it impossible for me to tell if he has any design patent rights to his design.

From a copyright point of view, the issues are a little different. It does not take a great deal of effort or expense to register a copyright. The copyright lasts a lot longer than a design patent (life of the author plus 70 years). HOWEVER, a copyright protects the expression NOT the idea.

What this means is that I can make a movie about a mafia family set during the 40's through today, but I cannot take the literal expression (dialog and images from the Godfather). So assuming Mr. dewy4 does have a copyright on his design, the question is how different is yours from his and when did he obtain his copyright.

If your lamos closely follow the WOOD design, then his design may infringe their copyright. While, I wish I could give you clearer advice, without more facts its impossible.