General Mills v. Hunt-Wesson, Inc.

917 F. Supp. 663, 41 U.S.P.Q. 2d (BNA) 1420, 1996 U.S. Dist. LEXIS 5927, 1996 WL 84848
CourtDistrict Court, D. Minnesota
DecidedJanuary 22, 1996
Docket3-95-98
StatusPublished
Cited by1 cases

This text of 917 F. Supp. 663 (General Mills v. Hunt-Wesson, Inc.) is published on Counsel Stack Legal Research, covering District Court, D. Minnesota primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
General Mills v. Hunt-Wesson, Inc., 917 F. Supp. 663, 41 U.S.P.Q. 2d (BNA) 1420, 1996 U.S. Dist. LEXIS 5927, 1996 WL 84848 (mnd 1996).

Opinion

MEMORANDUM OPINION AND ORDER

DAVIS, District Judge.

INTRODUCTION

Presently before the court are cross-motions for summary judgment. Defendant Hunt-Wesson, Inc. seeks a declaration of non-infringement with respect to U.S. Patent No. 4,267,420 (the ‘420 patent’ or the ‘Bras-tad patent’). Plaintiff General Mills seeks partial summary judgment on the scope of the ’420 claims, and asserts that there remain disputed fact issues which preclude summary resolution of the infringement question. For the reasons set forth below, the court denies Plaintiffs motion and grants Defendant’s motion for summary judgment of non-infringement.

FACTS

This dispute focuses on the use of a device called a “susceptor” in the heating of microwave popcorn. General Mills manufactures “Pop Secret”, while Hunt-Wesson markets a line ' of “Orville Redenbacher” products. Both of these products incorporate a susceptor into the microwave bag containing the popcorn. To understand why this fact has become the subject of the parties’ heated dispute, it is necessary to review the history of microwave cooking.

Microwave ovens were first marketed in the 1960s. Microwave cooking uses molecular friction to generate heat, whereas conventional methods rely on radiant or conductive heat. Microwaving is well-suited for certain foods, but for others, “according to the time honored custom, it is a matter of necessity from the point of view of taste, of sight, and for general gastronomic appeal to have some browned portion on the outer surface” of the food. U.S. Patent No. 8,783,220 to Tanizaki col. 1, lines 27-30, attached as Exh. 3 to Decl. of James. Micr'owave ovens, however, cannot provide this.

Since its inception, there have been numerous developments in the art of microwave cooking aimed at solving this problem, one intrinsic to the physics of microwaving. It was found that placement of a thin conductive film on the cooking surface could effect the color and texture changes desirable in certain foods by converting microwave energy to heat. This conversion simulated the results obtained with a frying pan or other conventional methods. In 1958, a patent was issued to Copson for the invention of a dish-like utensil which possessed this quality, and thus caused food “to assume a browned, seared, or crusted condition.” U.S. Patent No. 2,330,162 to Copson, col. 1, line 24, attached as Exh. 2 to Decl. Of James. In the 1960’s, Raytheon developed a “Microbrowner” dish, comprised of a Pyrex pie dish lined with a chemically-deposited coating of tin oxide. Buffler Aff., para 3. By its nature, the Mierobrowner was rigid and inflexible. Id., at para 4. Thus, it was not useful for applications requiring browning or crispening of the entire surface of the food, i.e., not just the bottom. In 1974, a similar patent was issued to Tanizaki. U.S. Patent No. 3,783,-220, attached as Exh. 3 to Decl. of James.

In 1976, Charles Turpin of Pillsbury sought to harness the browning/crispening power of the susceptor in combination with a disposable package for foods such as pizza. U.S. Patent No. 4,190,757, attached as Exh. 4 to James Decl. Pizza, however, only requires browning on the bottom surface. Foods requiring all-around crispening had to await the arrival of the invention which has given rise to this litigation.

The Brastad Patent

The Brastad patent comprises a flexible susceptor which achieves the goal of browning and/or crispening the entire surface of the food item. The susceptor is flexible, allowing it to be wrapped around the food, so that the microwave-generated heat which its design makes possible may be imparted to the entire surface. The ’420 contains two independent claims which are at issue here:

Claim 1
In combination with a food item capable of having its color changed or being cris- *665 pened by thermal energy, said food item to be heated in a microwave oven,
(a) wrapping material conforming generally to the shape of said food item comprising
(b) a flexible dielectric substrate having a thin semiconducting coating thereon residing in a close proximal relation to a substantial surface portion of said food item,
(e) said thin semiconducting coating having the property of being able to convert a portion of the microwave energy of a microwave oven into heat in the coating itself
(d) to thereby change the color or crispness of the surface of the food item
(e) while permitting the remainder of the said microwave energy to pass through the wrapping material to dielectrically heat the food item.
Claim 7
In combination with a food item capable of having its color changed or being cris-pened by thermal energy, said food item to be heated in a microwave oven,
(a) flexible dielectric material having a substantial portion thereof conforming generally to the shape of the food item,
(b) and a relatively thin flexible layer of metal carried by said dielectric material,
(c) said metallic layer also conforming generally to the shape of the food item and residing in a proximal relation thereto and
(d) having the property of being able to convert a proportion of the microwave energy of a microwave oven into heat in the metallic layer itself
(e) to thereby change the color or crispness of the surface of the food item adjacent thereto
(f) while permitting the remainder of the said microwave energy to pass through the flexible dielectric material to dielec-trically heat the food item.

Microwave Popcorn

Microwave popcorn is familiar to most. However, the submissions of the parties have illuminated previously unimagined complexities in this deceptively simple-looking art. Prior to popping, a kernel is essentially a hard, inedible pellet comprised of three main parts: (1) the pericarp, which is the tough, protective outer layer surrounding (2) the endosperm, and (3) the gemí. The “floury” portion of the endosperm contains millions of closely arranged cells containing starch and moisture. When heated, some of this moisture is converted into steam, but most of it is “superheated”, and remains in liquid form. This superheated moisture is confined by the pericarp, which is subjected to increasing pressure. Eventually, the pericarp ruptures, and explodes in a familiar “pop”. The superheated moisture is immediately released and vaporized, causing the starch to quickly gela-tinize and expand into the edible, three-dimensional network referred to as “popcorn”.

When Hunt-Wesson entered the nascent shelf-stable microwave popcorn market in the early 1980s, it did not incorporate a susceptor into its microwave bag. According to Hunt-Wesson, a drawback associated with its product was the existence of “unpops” — un-popped kernels remaining in the bag. Consumers accordingly felt that they were somehow “cheated”.

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917 F. Supp. 663, 41 U.S.P.Q. 2d (BNA) 1420, 1996 U.S. Dist. LEXIS 5927, 1996 WL 84848, Counsel Stack Legal Research, https://law.counselstack.com/opinion/general-mills-v-hunt-wesson-inc-mnd-1996.