It is generally stated in that one must both show ownership of and give the public the invention in order to get the monopoly rights of a claim (e.g. 112 in US, Art. 83 EPO).
However, for purposes of validity, is it acceptable to make a broad genus claim (e.g. all filamentous lightbulbs), but only disclose a few embodiments (e.g. with a horse hair filament), even when that scope (at least on its face) would include other embodiments that were unknown and/or required undue experimentation to be operably realized at the time of disclosure (e.g. carbon nanotubes as filament)? See the diagram below.
Note that the question does not relate to instances where an additional limitation is added (e.g. a frosted lightbulb), but to the more fundamental case where the claimed limitation (e.g. a filament) is satisfied with an embodiment unknown at the time of disclosure. In other words, the typical "three legged chair covers a four legged chair" would not apply.
I often see such broad non-enabled/non-sufficiently disclosed claims. However, the spirit of the law does not seem to support this, and e.g. this wikipedia article agrees:
Patents may fail this test if they claim more than they teach--for example, a patent that claims all light bulbs but that only explains how to make a particular type of light bulb.
In a previous question, I asked generally about infringement of such broad claims, the answer of which was, paraphrasing, "claim construction is limited to the intent of the claim terms". The question I want to ask here is: are such broad claims invalid when an unenabled/non-writtenly-described embodiment is identified? This is in the spirit of, "claims should be taken at face value" in the context of validity.