DCT
1:20-cv-00352
Inland Diamond Products Co v. Cherry Optical Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Inland Diamond Products Co. (Michigan)
- Defendant: Cherry Optical Inc. (Wisconsin)
- Plaintiff’s Counsel: BROOKS KUSHMAN P.C.
- Case Identification: 1:20-cv-00352, E.D. Wis., 03/03/2020
- Venue Allegations: Venue is alleged to be proper based on Defendant's principal place of business being located within the district, as well as alleged acts of infringement, sales, and placement of products into the stream of commerce within the Eastern District of Wisconsin.
- Core Dispute: Plaintiff alleges that Defendant’s eyeglass products, which incorporate plastic lenses fitted into wire frames, infringe patents related to the specific geometric design of a lens bevel that creates a compressed, interference fit within an eyeglass frame.
- Technical Context: The technology addresses a long-standing problem in the optical industry: the tendency for plastic eyeglass lenses to loosen and fall out of frames due to material shrinkage or stress over time.
- Key Procedural History: The complaint notes that both patents-in-suit survived inter partes review (IPR) proceedings at the USPTO. While several claims were cancelled in each IPR, key dependent claims now asserted in this litigation were found patentable. This history suggests the asserted claims have already withstood a significant validity challenge, which may focus the instant case more squarely on questions of infringement.
Case Timeline
| Date | Event |
|---|---|
| 2009-08-12 | Earliest Priority Date for '360 and '130 Patents |
| 2014-01-28 | U.S. Patent No. 8,636,360 Issues |
| 2016-08-02 | U.S. Patent No. 9,405,130 Issues |
| 2019-05-23 | USPTO issues Final Written Decision in IPR for '360 Patent |
| 2019-08-27 | USPTO issues Final Written Decision in IPR for '130 Patent |
| 2020-03-03 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 8,636,360 - Beveling Wheel, Method for Forming a Beveled Lens for Use with Eyeglasses and a Beveled Lens, issued January 28, 2014
The Invention Explained
- Problem Addressed: The patent’s background describes how plastic lenses, which constitute the vast majority of the market, can shrink or creep, causing them to fall out of eyeglass frames. It notes that beveling techniques designed for rigid glass lenses, which intentionally avoid contact between the bevel’s sharpest point (the vertex) and the frame’s channel bottom to prevent cracking, result in a less secure fit for more malleable plastic lenses (ʼ360 Patent, col. 1:12-44).
- The Patented Solution: The invention is a plastic lens with a specially shaped bevel designed to create an interference fit. The key is a geometric mismatch: the angle of the frame's V-shaped receiving channel ("first angle") is greater than the angle of the lens's V-shaped bevel ("second angle"). When the lens is inserted, this mismatch forces the vertex of the lens bevel into firm, compressive contact with the bottom of the frame channel, creating a more secure assembly that resists loosening ('360 Patent, Abstract; col. 2:1-4).
- Technical Importance: This design leverages the deformability of plastic to create a secure, compressed fit that was intentionally avoided with fragile glass lenses, addressing a common failure point in modern eyewear (ʼ360 Patent, col. 1:32-44).
Key Claims at a Glance
- The complaint asserts at least dependent claim 2 (Compl. ¶15). Claim 1, from which it depends, was cancelled during a post-grant proceeding (IPR2018-00178).
- Essential elements of claim 2 (incorporating the limitations of cancelled claim 1):
- A prescription plastic lens for use in an eyeglass frame having a receiving channel with a "first angle."
- The lens has a peripheral edge with a bevel extending to a vertex.
- The bevel has a "second angle" adjacent to the vertex.
- The "first angle" of the frame channel is greater than the "second angle" of the lens bevel.
- The vertex of the bevel is in contact with the receiving channel bottom, creating an "interference fit."
- The portion of the vertex in contact with the channel bottom is "in compression."
- The height of the bevel ranges from 0.25 mm to 1.1 mm.
- The complaint does not explicitly reserve the right to assert other dependent claims for this patent, but notes infringement of "other claims" (Compl. ¶15).
U.S. Patent No. 9,405,130 - Beveling Wheel, Method for Forming a Beveled Lens for Use with Eyeglasses and a Beveled Lens, issued August 2, 2016
The Invention Explained
- Problem Addressed: The ’130 Patent addresses the same technical problem as its parent '360 Patent: the unreliability of conventional lens mounting techniques when applied to plastic lenses, which can lead to lenses falling out of frames (ʼ130 Patent, col. 1:26-39).
- The Patented Solution: Rather than claiming the lens alone, this patent claims the final assembled product: a pair of eyeglasses. The claimed solution is the combination of an eyeglass frame and a plastic lens featuring the same specific geometric relationship as in the ’360 Patent. The bevel angle is less than the channel angle, causing the vertex of the lens bevel to be compressed into the channel bottom to form a secure, interference fit (ʼ130 Patent, Abstract; col. 2:1-13).
- Technical Importance: This patent protects the commercial embodiment of the invention—the complete pair of eyeglasses—thereby covering the final assembled product sold to consumers (ʼ130 Patent, col. 1:42-54).
Key Claims at a Glance
- The complaint asserts at least dependent claim 4 (Compl. ¶26). Claims 1 and 3, from which it depends, were cancelled during a post-grant proceeding (IPR2018-00596).
- Essential elements of claim 4 (incorporating the limitations of cancelled claims 1 and 3):
- A pair of eyeglasses comprising an eyeglass frame and a secured prescription plastic lens.
- The frame has a receiving channel with a "first angle."
- The lens has a bevel extending to a vertex, and the bevel is a "triangle having an apex."
- The bevel has a "second angle" that is less than the "first angle."
- The vertex is in contact with the channel bottom, creating an "interference fit" and is "in compression."
- The apex has an angle in the range from 100 degrees to 130 degrees.
- The complaint notes the analysis also applies to exemplary claim 5 but does not detail its limitations (Compl. ¶26).
III. The Accused Instrumentality
Product Identification
- The complaint identifies the "Accused Eyeglass Products" as "eyeglasses having lenses made from plastic lens material and wire frames" made, used, or sold by Defendant Cherry Optical (Compl. ¶6.b). A specific example product, branded "MODERN JAZZ," is depicted (Compl. Photograph 1, p. 4).
Functionality and Market Context
- The accused functionality is the mechanical structure of the eyeglasses, specifically the interface between the beveled plastic lens and the receiving channel of the frame (Compl. ¶¶ 17-18). The complaint alleges these products are sold through "Internet and brick-and-mortar outlets" across the United States (Compl. ¶3). The complaint presents a magnified cross-section of the assembled product, purporting to show the lens bevel seated within the frame channel (Compl. Photograph 2, p. 5).
IV. Analysis of Infringement Allegations
'360 Patent Infringement Allegations
| Claim Element (from Independent Claim 2) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A prescription plastic lens... said eyeglass frame having a receiving channel defined by opposed interior wall surfaces having a first angle therebetween... | The accused products are alleged to be prescription plastic lenses for use in an eyeglass frame with a receiving channel. This is shown in an annotated photograph of a cut-away section of the accused product (Compl. Photograph 2). | ¶17 | col. 9:36-40 |
| the plastic lens comprising: a prescription lens body generally defined by a peripheral edge, the peripheral edge having a bevel extending away from the peripheral edge to a vertex. | The accused plastic lens is alleged to have a body with a peripheral edge from which a bevel extends to a vertex. | ¶18 | col. 9:42-46 |
| the bevel having a distal portion having a second angle defined between opposing sides of the bevel adjacent to the vertex. | The complaint alleges, based on "reasonable inference from...the picture shown," that the bevel has a distal portion with a second angle at its vertex. | ¶19 | col. 9:46-49 |
| at least a portion of the vertex of the bevel being in contact with the receiving channel bottom and having an interference fit with the receiving channel bottom when held within the eyeglass frame. | Based on inference from a photograph of the assembled product, the complaint alleges the vertex of the bevel contacts the channel bottom and creates an interference fit. | ¶21 | col. 9:49-54 |
| the first angle being greater than the second angle; wherein the portion of the vertex in contact with the receiving channel bottom is in compression once the plastic lens is fitted in the frame. | The complaint alleges via "reasonable inference" that the frame channel's angle is greater than the bevel's vertex angle, causing the vertex to be in compression when the lens is fitted in the frame. | ¶22 | col. 9:54-58 |
| the height of the bevel ranges from 0.25 mm to 1.1 mm. | The complaint presents an annotated photograph of the lens bevel with a measurement of "0.031 inch," which it states is equal to 0.79 mm, a value falling within the claimed range (Compl. Photograph 4). | ¶23 | col. 9:59-60 |
'130 Patent Infringement Allegations
| Claim Element (from Independent Claim 4) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A pair of eyeglasses, comprising: an eyeglass frame having a receiving channel, the receiving channel defined by opposed interior wall surfaces having a first angle therebetween... | The accused product is alleged to be a pair of eyeglasses with a frame containing a receiving channel defined by interior walls. An annotated photograph purports to show this channel and its measured angle of 113.590° (Compl. Photograph 3). | ¶¶27-28 | col. 9:51-57 |
| a prescription plastic lens secured in the eyeglass frame and including a body having a peripheral edge. | The accused eyeglasses are alleged to include a secured plastic lens with a peripheral edge. | ¶29 | col. 9:58-60 |
| the peripheral edge having a bevel extending away from the peripheral edge to a vertex... the bevel is a triangle having an apex. | The lens is alleged to have a bevel extending to a vertex. The complaint alleges the bevel is a triangle with an apex, citing an annotated photograph of the lens profile (Compl. Photograph 4). | ¶¶30, 33 | col. 9:60-62, 10:3 |
| the bevel having a distal portion having a second angle... being less than the first angle of the receiving channel... at least a portion of the vertex of the bevel being in contact with the receiving channel bottom, having an interference fit... and being in compression. | Based on "reasonable inference" from photographs, the complaint alleges the bevel's angle is less than the frame's channel angle, resulting in the vertex contacting the channel bottom with an interference fit and being in compression. | ¶¶31-32 | col. 9:62-68 |
| the apex has an angle in the range from 100 degrees to 130 degrees. | The complaint presents an annotated photograph of the frame with a measurement indicating the angle of the apex is 113.590°, which falls within the claimed range (Compl. Photograph 3). | ¶34 | col. 10:5-6 |
Identified Points of Contention
- Evidentiary Questions: The complaint's infringement theory relies heavily on "reasonable inference[s]" drawn from annotated photographs (Compl. ¶¶19, 28, 30). A central point of contention may be whether these static images, without physical measurements of forces, material deformation, or manufacturing specifications, are sufficient to prove the functional limitations of "interference fit" and "in compression."
- Technical Questions: What evidence does the complaint provide that the observed contact between the lens and frame (Compl. Photograph 2, p. 5) results in the specific state of "compression" required by the claims, as opposed to simple contact without significant force? The allegations of angular measurements (Compl. Photograph 3, p. 5) may support the geometric prerequisite for compression, but the existence of compression itself remains an inferential allegation.
V. Key Claim Terms for Construction
The Term: "interference fit"
- Context and Importance: This term is crucial as it defines the nature of the physical relationship between the lens and the frame. The infringement analysis will depend on whether the alleged contact in the accused products meets the legal and technical definition of an "interference fit," which generally implies that two parts are sized such that they must be forced together.
- Intrinsic Evidence for a Broader Interpretation: The patent does not provide an explicit definition, which could support an argument for its plain and ordinary meaning. The objective is to provide a "relatively secure assembly," which might not require a specific quantum of force (ʼ360 Patent, col. 3:27-28).
- Intrinsic Evidence for a Narrower Interpretation: The specification repeatedly links the "interference fit" to solving the problem of lens "shrinkage and/or creep" (ʼ360 Patent, col. 1:15-17). This context suggests the fit must be substantial enough to actively counteract these material degradation effects over a prolonged period, implying more than incidental contact.
The Term: "in compression"
- Context and Importance: This term describes the physical state of the lens vertex. Proving this element is infringed may be a key challenge. Practitioners may focus on this term because demonstrating that a component is "in compression" often requires more than visual evidence, such as data from force sensors or finite element analysis.
- Intrinsic Evidence for a Broader Interpretation: The patent states that a thermoset bevel can "tolerate moderate stress when the bevel...is initially compressed," which could be interpreted as any non-zero compressive stress (ʼ360 Patent, col. 4:52-54).
- Intrinsic Evidence for a Narrower Interpretation: The claims explicitly link the state of being "in compression" to the geometric condition where the frame's angle is greater than the bevel's angle (ʼ360 Patent, col. 9:54-58). This suggests "in compression" is the necessary and direct physical result of this specific claimed geometry, not just any incidental contact.
VI. Other Allegations
- Willful Infringement: The complaint does not allege specific facts to support pre-suit knowledge of the patents or egregious conduct. However, the prayer for relief includes a request for enhanced damages for willful infringement "if evidence is adduced through discovery or at trial," reserving the right to pursue this claim later in the proceedings (Compl. ¶D, p. 21).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of evidentiary proof: Can the plaintiff's reliance on annotated photographs and "reasonable inferences" satisfy its burden of proving the claimed physical states of "interference fit" and "in compression," or will the court require more direct evidence, such as physical testing data or expert-driven simulations, to substantiate these functional limitations?
- A key legal question will be one of claim scope: How will the court construe the term "interference fit"? Will its definition require a specific, measurable degree of force sufficient to counteract the material shrinkage detailed in the patent's background, or can it be satisfied by showing the claimed geometric mismatch and resulting contact alone? The resolution of this question will be fundamental to the infringement determination.