DCT
1:18-cv-06911
Varex Imaging Corp v. Richardson Electronics Ltd
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Varex Imaging Corporation (Delaware)
- Defendant: Richardson Electronics, Ltd. (Delaware)
- Plaintiff’s Counsel: Barack Ferrazzano Kirschbaum & Nagelberg LLP
- Case Identification: 1:18-cv-06911, N.D. Ill., 11/27/2018
- Venue Allegations: Venue is based on Defendant's corporate headquarters and principal place of business in La Fox, Illinois, which is alleged to be a regular and established place of business within the district.
- Core Dispute: Plaintiff alleges that Defendant’s ALTA750 replacement X-ray tubes infringe two patents related to thermal management technologies for high-power X-ray tubes.
- Technical Context: The patents relate to advanced cooling mechanisms for medical X-ray tubes, a critical component in computed tomography (CT) scanners where managing intense heat is essential for performance and longevity.
- Key Procedural History: This filing is an Amended Complaint. The complaint alleges that after Plaintiff filed its original complaint on October 15, 2018, Defendant removed marketing language from its website, such as "newly manufactured" and "new CT tube," which Plaintiff characterizes as an attempt to hide admissions relevant to an anticipated patent exhaustion defense.
Case Timeline
| Date | Event |
|---|---|
| 2000-09-28 | U.S. Patent No. 6,456,692 Priority Date |
| 2001-04-09 | U.S. Patent No. 6,519,317 Priority Date |
| 2002-09-24 | U.S. Patent No. 6,456,692 Issued |
| 2003-02-11 | U.S. Patent No. 6,519,317 Issued |
| c. 2018-06-01 | Accused ALTA750 Product Commercial Sale Begins |
| 2018-10-15 | Plaintiff Files Original Complaint |
| 2018-11-27 | Plaintiff Files Amended Complaint |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 6,456,692 - HIGH EMISSIVE COATINGS ON X-RAY TUBE COMPONENTS (Issued Sep. 24, 2002)
The Invention Explained
- Problem Addressed: In high-power X-ray tubes, intense heat generated at the anode can conduct through the rotor assembly and damage sensitive components, particularly the ball bearings that support the spinning rotor. This heat can degrade lubricants and reduce the operational life of the entire tube ( ’692 Patent, col. 2:1-4).
- The Patented Solution: The invention applies a coating with high thermal emissivity to a component, such as the rotor, which is situated between the heat-generating anode and the heat-sensitive bearings. This specialized coating enhances the component's ability to radiate heat away to adjacent cooling structures before it can be conducted to the bearings, thereby protecting them and extending the tube's life (’692 Patent, Abstract; col. 6:45-58). The coating is specifically designed to adhere well and have a compatible thermal expansion coefficient to prevent flaking or spalling inside the tube's vacuum environment (’692 Patent, col. 7:38-46).
- Technical Importance: This approach provided a more effective way to manage thermal loads in X-ray tubes, enabling higher-power operation and improving the reliability of these critical medical components.
Key Claims at a Glance
- The complaint asserts independent claim 1 and dependent claims 3, 6, 7, and 12 (Compl. ¶81).
- Independent Claim 1 requires:
- A vacuum enclosure having an electron source and anode disposed therein.
- A rotor at least partially received within the anode and operably connected to it.
- A bearing assembly that rotatably supports the rotor and is at least partially received within the anode.
- An emissive coating on a portion of the rotor, where the coating is made of a material that increases the emissivity of the rotor's surface.
U.S. Patent No. 6,519,317 - DUAL FLUID COOLING SYSTEM FOR HIGH POWER X-RAY TUBES (Issued Feb. 11, 2003)
The Invention Explained
- Problem Addressed: Conventional cooling systems using a single coolant (like dielectric oil) have limited heat-absorption capacity. This is often insufficient for the extreme heat levels in modern, high-power X-ray tubes, leading to potential coolant boiling, structural stress, and shortened device lifespan (’317 Patent, col. 3:5-24).
- The Patented Solution: The patent describes a dual-fluid cooling system. A first coolant (e.g., dielectric oil) remains in the main housing to cool general electrical components. A second, independent coolant circuit circulates a fluid with higher heat capacity (e.g., a pressurized water/glycol mixture) through dedicated passageways integrated directly into the hottest parts of the X-ray tube, such as a "shield structure" near the anode. This allows for more aggressive and targeted heat removal where it is most needed (’317 Patent, Abstract; col. 4:13-30).
- Technical Importance: This dual-system approach enables more efficient thermal management, facilitating the development and reliable operation of more powerful and demanding X-ray systems, such as those in advanced CT scanners.
Key Claims at a Glance
- The complaint asserts claims 34-37 (Compl. ¶94).
- Independent Claim 34 requires:
- An X-ray tube substantially disposed within a housing.
- A cooling system that includes:
- A first coolant disposed in the housing to absorb heat from the X-ray tube.
- At least one fluid passageway for a second coolant, where the passageway is at least partially defined in a "shield structure" located between the target anode and the electron source of the X-ray tube.
III. The Accused Instrumentality
Product Identification
- The ALTA750 X-ray tube (Compl. ¶38).
Functionality and Market Context
- The ALTA750 is marketed as a "form, fit and function replacement" for Plaintiff's MCS-7078 "Snowbird" X-ray tube (Compl. ¶64). The complaint alleges a specific manufacturing process: Defendant obtains used Varex Snowbird tubes, cuts them open, and scavenges certain parts (e.g., the anode assembly and thermal disk) (Compl. ¶43). These used parts are then allegedly combined with newly manufactured components—including a new vacuum enclosure, bearing assembly, electron source, and shield structure—to create the ALTA750 (Compl. ¶42, ¶44, ¶52). This newly assembled tube is then placed into a used Varex housing (Compl. ¶45) and filled with a new dielectric oil (first coolant) and a new propylene glycol/water mixture (second coolant) (Compl. ¶58). The complaint alleges the product is not a repair or refurbishment but a "new article of manufacture" created to compete with Plaintiff's OEM products (Compl. ¶75). The side-by-side photograph provided in the complaint shows the Varex and Richardson tubes, which appear visually similar (Compl. ¶60).
IV. Analysis of Infringement Allegations
'692 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a vacuum enclosure having an electron source and anode disposed therein... | Defendant manufactures a "wholly new" vacuum enclosure and supplies a "new electron source" combined with an anode assembly scavenged from a used Varex tube. | ¶54, ¶56, ¶83 | col. 5:9-11 |
| a rotor at least partially received within said anode, and wherein the rotor is operably connected to the anode | The ALTA750 incorporates a target anode assembly taken from a used Varex tube, which includes the rotor. | ¶83 | col. 5:16-19 |
| a bearing assembly rotatably supporting said rotor and at least partially received within said anode... | Defendant supplies a "new bearing assembly" that is disposed within the tube to rotatably support the rotor. | ¶57, ¶83 | col. 5:26-34 |
| an emissive coating disposed on at least a portion of said rotor that is disposed within the anode... | The complaint makes a general allegation that the ALTA750 tube includes all elements of claim 1, which would implicitly include the emissive coating on the scavenged rotor. | ¶83 | col. 6:45-51 |
'317 Patent Infringement Allegations
| Claim Element (from Independent Claim 34) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| (a) an x-ray tube substantially disposed within a housing | The newly manufactured ALTA750 tube is placed within a "used Varex Snowbird X-ray tube housing." | ¶45, ¶96 | col. 6:65-67 |
| (b)(i) a first coolant disposed in the housing so that at least a portion of heat dissipated by the x-ray tube is absorbed by the first coolant | Defendant deposits new dielectric oil into the housing, which surrounds the ALTA750 tube. | ¶46, ¶58, ¶96 | col. 8:46-51 |
| (b)(ii) at least one fluid passageway...being at least partially defined in a shield structure disposed between a target anode and an electron source of said x-ray tube | Defendant allegedly machines a "new shield structure" and circulates a second coolant (a propylene/glycol mixture) through a passageway within it. | ¶58, ¶59, ¶96 | col. 9:1-8 |
- Identified Points of Contention:
- Reconstruction vs. Repair: The central dispute appears to be whether Defendant's activities constitute permissible repair of a used product (for which patent rights would be exhausted) or impermissible reconstruction that creates a "new" infringing article. The complaint's detailed allegations about Defendant manufacturing and replacing core components like the vacuum enclosure, bearing assembly, and shield structure (Compl. ¶52, ¶54, ¶57, ¶59) suggest this will be the primary legal battleground.
- Scope Questions: For the '692 patent, a key question is whether the "emissive coating" limitation is met. The complaint does not specify how this element is met, raising the question of what evidence Plaintiff has that the coating on the scavenged rotor satisfies the claim requirements.
- Technical Questions: For the '317 patent, a key question will be whether Defendant's newly machined "shield structure" falls within the scope of the claimed term. The complaint's before-and-after screenshots of Defendant's website, showing the removal of the term "newly manufactured," may be presented as evidence of Defendant's awareness of this issue (Compl. ¶69).
V. Key Claim Terms for Construction
The Term: "An x-ray tube" (from '692 patent, claim 1)
- Context and Importance: Practitioners may focus on this term because the case appears to hinge on the legal doctrine of patent exhaustion. The core question is whether the accused ALTA750 is the same "x-ray tube" originally sold by Varex (and thus exhausted) or a "newly manufactured" tube created through impermissible reconstruction. The definition of what constitutes the "tube" will be central to this analysis.
- Intrinsic Evidence for Interpretation: The complaint itself frames this dispute by alleging Defendant's actions "is to make a new product, a second creation of the patented article" (Compl. ¶52) because essential components like the "vacuum enclosure," "bearing assembly," and "shield structure" are entirely new (Compl. ¶54, ¶57, ¶59). A court will need to determine if replacing these specific parts, particularly the vacuum enclosure which is essential for the tube's basic function, crosses the line from repair to reconstruction.
The Term: "shield structure" (from '317 patent, claim 34)
- Context and Importance: This term defines a key component of the patented dual-coolant system. Infringement of the '317 patent depends on the ALTA750 containing this feature. The complaint alleges Defendant "machines a new shield structure" (Compl. ¶59), making the definition of this term critical.
- Evidence for a Broader Interpretation: The claim itself defines the structure by its location: "disposed between a target anode and an electron source of said x-ray tube" (’317 Patent, col. 18:22-24). This locational definition could be argued to cover a range of physical forms.
- Evidence for a Narrower Interpretation: The specification describes the shield structure in more detail, including its function of defining an aperture for electrons to pass through (’317 Patent, col. 13:25-35). A party could argue the term should be limited to structures that perform all the functions described in the preferred embodiments.
VI. Other Allegations
- Indirect Infringement: The complaint alleges induced infringement of the '317 patent. The basis for this claim is that Defendant provides training programs and resources that allegedly instruct its customers and users on "system operation," "calibration," and "diagnostic procedures," thereby encouraging them to use the ALTA750 in an infringing manner (Compl. ¶103).
- Willful Infringement: Willfulness is alleged for both patents. For the '317 patent, the complaint alleges Defendant had "actual knowledge of the '317 patent prior to introducing the ALTA750 for commercial sale on or about June 2018" (Compl. ¶100). For both patents, the complaint alleges Defendant acted "in complete and reckless disregard of Varex's rights" (Compl. ¶91, ¶106).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of patent exhaustion: does Defendant's process of harvesting select components from spent Varex tubes and combining them with its own newly manufactured, essential parts (such as the vacuum enclosure and shield structure) constitute permissible repair of an existing article, or does it amount to the impermissible reconstruction of a "new" infringing product?
- A key question of infringement and claim scope will be whether the specific components newly manufactured by the Defendant, particularly the "shield structure" in the ALTA750, meet the technical limitations of the asserted claims as they would be construed by the court.
- A central evidentiary question will be what effect, if any, Defendant's alleged post-filing alteration of its marketing materials has on the case. Can this be used to support Plaintiff's theory of reconstruction and demonstrate the requisite knowledge and intent for a finding of willful infringement?