Photo Engineer
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There is another thread about the Light Farm that begun to digress as posts about patents were discussed. Here is some additional insight (again).
In a normal patent, let us say about t-grains, the patent discloses a method to make t-grains. It will work. But, this patent need not disclose the fact that a metal salt is added, such as Iridium, to improve reciprocity. It does not disclose the optimum gelatin, it does not disclose any keeping addenda, and it does not disclose the optimum sulfur + gold sensitization.
To get those items one must go to as many as 4 different patents, but since those patents do not need to talk about t-grains, the amounts used and methods of addition may be for cubes or octahetra or K-grains (klunkers). The method and amount of any of these might be vastly different for optimum performance on a t-grain. Those patents also work, and use the words "application to any emulsion type is possible by one skilled in the art". This means that if a new emulsion comes out someday, this method applies to it as well, we just don't have to reveal that information because we don't know yet ourselves. The method is so generic though that a good photographic engineer can eventually figure it out.
In addition, there are trade secrets applied during manufacturing that may completely alter the action of a given emulsion. This might include the fact that only one surfactant or hardener is good with this t-grain, and all others are not good.
So, the fundamental patent on making 1 micron, graded iodide t-grains with a given aspect ratio works, but is impossible to interpret unless you are: "one skilled in the art". Even reading the other related patents does not give a complete picture due to the fact that trade secrets need not be patented. In fact, once used in a product, trade secrets cannot be patented as that is considered to be 'disclosure' of the invention.
I would also add that cited patents do not tell the whole story. They lead one back on a trail of related t-grain patents (if any) but not to addenda or finishing even if those patents exist. Now, to date, I see few patents on emulsion finishing and this is a critical step. In fact, it is one of the most critical and most secret at Kodak.
I worked with the originator of Kodak's highest speed emulsion during scaling from R&D to production. I would assume it to be on the order of 1600 speed, but I know nothing about the finish, as it was done after my work with the emulsion was done. It was even done by another department.
I hope this extends your understanding of the fact that patents can end up being nearly useless.
PE
In a normal patent, let us say about t-grains, the patent discloses a method to make t-grains. It will work. But, this patent need not disclose the fact that a metal salt is added, such as Iridium, to improve reciprocity. It does not disclose the optimum gelatin, it does not disclose any keeping addenda, and it does not disclose the optimum sulfur + gold sensitization.
To get those items one must go to as many as 4 different patents, but since those patents do not need to talk about t-grains, the amounts used and methods of addition may be for cubes or octahetra or K-grains (klunkers). The method and amount of any of these might be vastly different for optimum performance on a t-grain. Those patents also work, and use the words "application to any emulsion type is possible by one skilled in the art". This means that if a new emulsion comes out someday, this method applies to it as well, we just don't have to reveal that information because we don't know yet ourselves. The method is so generic though that a good photographic engineer can eventually figure it out.
In addition, there are trade secrets applied during manufacturing that may completely alter the action of a given emulsion. This might include the fact that only one surfactant or hardener is good with this t-grain, and all others are not good.
So, the fundamental patent on making 1 micron, graded iodide t-grains with a given aspect ratio works, but is impossible to interpret unless you are: "one skilled in the art". Even reading the other related patents does not give a complete picture due to the fact that trade secrets need not be patented. In fact, once used in a product, trade secrets cannot be patented as that is considered to be 'disclosure' of the invention.
I would also add that cited patents do not tell the whole story. They lead one back on a trail of related t-grain patents (if any) but not to addenda or finishing even if those patents exist. Now, to date, I see few patents on emulsion finishing and this is a critical step. In fact, it is one of the most critical and most secret at Kodak.
I worked with the originator of Kodak's highest speed emulsion during scaling from R&D to production. I would assume it to be on the order of 1600 speed, but I know nothing about the finish, as it was done after my work with the emulsion was done. It was even done by another department.
I hope this extends your understanding of the fact that patents can end up being nearly useless.
PE