Method for Processing Images from 3D Camera System Found Invalid under 35 U.S.C. § 101

It is well-known law today that under 35 U.S.C. § 101, a patent claim that recites a solution to a problem but not the means of achieving it is likely not drawn to patent-eligible subject matter.  Courts have found that such claims, rather than disclosing a concrete solution, seek to monopolize the very idea of a solution itself.

In the present case, Sungkyunkwan University sued LMI Technologies in the U.S. District Court for the Northern District of California for infringement of its U.S. Patent No. 7,957,639.

The '639 patent is directed to determining an optimal exposure of a structured-light based 3D camera.  The 3D camera of the '639 patent includes a camera and a projecting unit such as a beam projector that illuminates a predetermined pattern on an object, captures an image of the object with the pattern illuminated thereon, and obtains 3D information by analyzing the obtained pattern.  The '639 patent describes that the precision of the calculated 3D data depends on how accurately the pattern is discriminated from the captured image.  To obtain optimal exposure for pattern discrimination, an image captured from a projected pattern without spread phenomenon (saturation) is compared with an image captured from a non-projected reference scene, and a pattern may be optimally discriminated when the intensity difference therebetween becomes the maximum.  As a scale for the intensity difference, SNR and difference in brightness are used.  The '639 patent describes that to determine an optimal exposure level of a camera according to dynamically changing environmental factors, the structured light based camera system employs a method for automatically determining an optimal exposure level by analyzing an image captured at a predetermined exposure level.

Claim 1 is representative and is reproduced below:

1.  A method for determining an optimal exposure of a structured light based three dimensional (3D) camera system including a projecting means for illuminating a predetermined pattern on a target object, an image capturing means for capturing an image of the target object with the pattern projected, and a processing means for reconstructing 3D data based on the captured image, wherein the method comprises the steps of:
    obtaining an image of a target object with a predetermined pattern projected thereon, which is illuminated from a projecting means, and an image of the target object without a predetermined pattern projected thereon; and
    determining automatically an optimal exposure level of the structured light based 3D camera system using said two kinds of images.

LMI filed a motion to dismiss the case based on claim 1 being directed to an abstract idea.  The District Court agreed, and found that claim 1 of the '639 patent is directed to an abstract idea.

To begin, the District Court noted that the claim's preamble recites the technological context of the invention and its end goal; the first element restates the technological context; and the second element restates the end goal.  Following, the District Court found that the method of optimizing exposure on a structured-light 3D camera -- the "how" that's nominally the subject of the claimed invention -- is absent.

The closest claim 1 comes to disclosing how the invention intends to optimize exposure is its reference to two images generated by a structured-light camera (e.g., "determining automatically an optimal exposure level of the structured light based 3D camera system using said two kinds of images").  But as the patent specification makes clear, the images aren't the subject of the invention -- "patterned" images are an inherent part of the prior-art cameras, and "unpatterned" images are just ordinary images.  The District Court found that the claim's repeated reference to the steps involved in using a structured-light camera adds nothing of substance to the method that's actually being claimed here.

By describing the function of the prior-art cameras, the University situated the claimed invention in the technological environment in which it operates, but it did not explain the invention itself.

The overall result is to place the full weight of patent-eligibility on the claim's use of the word "using" (e.g., "determining automatically an optimal exposure level . . . using said two kinds of images").  But whatever method might be encompassed by the idea of "using" patterned and unpatterned images, claim 1 doesn't disclose it.

The District Court found that the only effect of the word "using" is to disclose the starting point of a method that the claim doesn't explain:  "using" two images, you get an optimal exposure, or rather "using" certain inputs, you get a certain result.  The District Court found that this is not enough to make claim 1 concrete because a claim cannot recite inputs and end result and attempt to claim every way of arriving at the end result.

The District Court noted that the patent specification in fact teaches the steps involved in optimizing exposure on a structured-light camera.  But claim 1 does not recite such steps.

Finally, the District Court noted that at oral argument, counsel for the University made vague reference to the fact that the '639 patent is translated from a Korean patent, as if to suggest that some concrete aspect of claim 1 was lost in translation.  But the District Court was quick to note that it's difficult to understand how this helps the University, because it's the U.S. patent that the University is asserting.

Thus, the District Court granted the motion to dismiss.

The end result here is not too surprising given that the claim lacks details of how the method is performed to achieve the recited result.  A claim that recites to obtain two types of images, and then to automatically determine an exposure level using the two kinds of images simply lacks enough detail to satisfy 35 U.S.C. § 101 under today's standards.  Although not discussed by the District Court, the term "automatically" also tends to offer no help in these instances since the claim fails to describe how the function is automatically performed as well.

Sungkyunkwan University v. LMI Technologies (USA) Inc. (N.D. Cal. 2017)
Order Granting Motion to Dismiss by District Judge Vince Chhabria