Full opinion text
OPINION AND JUDGMENT GADOLA, District Judge. This is a patent infringement action in which the liability and damages issues have been bifurcated. Beginning on March 10, 1997 and continuing through March 27, 1997, this Court held a bench trial oh the matter of liability. During the course of the trial, this Court received testimony and documentary evidence as well as dozens of physical exhibits. Post trial briefing was completed on May 30,1997. This Opinion represents the Court’s findings of fact and conclusions of law with respect to all issues. These findings of fact and conclusions of law result from a careful consideration of all of the evidence and the documentary and physical exhibits in light of the pertinent law and the Court’s observation of the witnesses and its evaluation of their demeanor, qualifications and credibility. Every finding of fact that may be construed to incorporate a conclusion of law is hereby adopted, as a conclusion of law. Every conclusion of law that may be. construed to incorporate a finding of fact is hereby adopted as a finding of fact. The sub-headings used herein are for convenience only. If a finding of fact or conclusion of law is pertinent to any determination other than that indicated by the heading under which it appears, it is deemed adopted as a finding of fact or conclusion of law applicable to such other determination or determinations as may be appropriate. FINDINGS OF FACT I. NATURE OF THE ACTION AND PARTIES 1. This is a patent infringement action with federal jurisdiction based upon 28 U.S.C. § 1338(a). 2., Plaintiff, Renishaw pic (“Renishaw”), is an English corporation with its principal place of business in New Mills, Wotton-under-Edge, Gloucestershire, England. PO 13. corporation with its principal place of business in Via Saliceto, Bentivoglio, Italy. PO 13. 3. Defendant Marposs Societa’ Per Azioni is an Italian corporation with its principal place of business in Via Saliceto, Bentivoglio, Italy. PO 13. 4. Defendant Marposs Corporation is a New York corporation with its principal place of business in Auburn Hills, Michigan. PO 13. Marposs Corporation is the U.S. subsidiary of Marposs Societa’ Per Azioni and acts as a distributor of Marposs products in the United States. Tr 1022-23. 5. Marposs Societa’ Per Azioni and Mar-poss Corporation are collectively referred to herein as “Marposs.” 6. Renishaw filed suit against Marposs on .July 21, 1994, alleging willful infringement of three Renishaw patents by Marposs’ MIDA touch probes. The initial patents asserted were U.S. Patent No. 4,153,998 (the “'998 patent”), U.S. Patent No. 4,270,275 (the “'275 patent”), and U.S. Patent No. 5,253,428 (the “'428 patent”). 7. Renishaw, with Marposs’ consent, filed a Stipulated Amended Complaint on November 30, 1994, further alleging the infringement by Marposs of U.S. Patent No. 5,353,-514 (the “'514 patent”). 8. On December 8, 1994, on the parties’ joint motion, the Court issued an order bifurcating liability and damages issues. 9. Renishaw sought and was granted leave to file a Second Amended Complaint on August 12, 1996, further alleging infringement by Marposs of U.S. Patent No. 5,491,-904 (the “'904 patent”). 10. Marposs, of course, denied all of Renishaw’s allegations of infringement and has asserted that Renishaw’s suit is in bad faith and seeks an award of attorneys’ fees pursuant to 35 U.S.C. § 285. PO 7-13. 11. The '998, '275, '428, '514 and '904 patents are wholly owned by Renishaw. PO 11,19. Tr 340, 368. 12. It is uneontested that the accused MIDA probes were made, and sold in the United States, after the applicable patent issue dates. Tr 1199-1200, 1203-04; PX 87, PX 575, pp. 64-65. 13. Renishaw claimed that the Marposs MIDA probes infringed claim 12 of the '998 patent, claims 1-5 of the '275 patent, claims 1-28 of the '428 patent, claims 1-28, 38 — 19 and 51-55 of the '514 patent, and claims 1-6 of the '904 patent in this action. PO 1. 14. Prior to trial, Renishaw designated as representative claims 1 and 4 of the '275 patent, claims 3, 6 and 55 of the '514 patent, and claim 2 of the '904 patent. Renishaw did not choose any representative claims from the '998 or '428 patents. PO 1. Pursuant to a stipulation between the parties, claims 3 and 6 of the '514 were subsequently dropped from consideration. 15. Thus, by agreement, the case was tried on the basis of representative claims 1 and 4 of the '275 patent, claim 55 of the '514 patent, and claim 2 of the '904 patent. Both parties agreed that the resolution of these claims will constitute a final resolution of all the asserted patents as if the case had been tried without representative claims. PO 1. II. OVERVIEW OF TECHNOLOGY A. Touch Probes 16. Touch probes are mechanical devices that have been used for many years for very accurately checking dimensions on coordinate measuring machines (“CMMs”) and on lathes, mills, machining centers, and other machining tools (collectively, “machining centers”). In the typical touch probe application, the touch probe is mounted on an arm that is part of the CMM or machining center. To measure, the arm is moved in order to bring the stylus of the touch probe into contact with the object to be measured. '904, col. 1,1. 21-27. 17. Touch probes do not measure objects by themselves. In general, a touch probe is simply a sophisticated switch that generates a repeatable signal. The repeatability of a probe is the ability of that probe to signal or trigger at the same point each time. All viable touch probes produce such repeatable trigger signals. The microprocessors and software within the CMM or machining center use the repeatable .trigger signal of the touch probe to produce an accurate measurement. Tr 521, 1632; DX 245, Bates No. 112341; '904, col. 1,1.15-28. 18. Modem touch probes produce trigger signals that are repeatable to the level of a single micron or less. A micron is one-millionth of a meter; a typical human hair has a thickness of 50 to 100 microns. Tr 156, 847, 850,1094,1308. 19. The patents in suit do not involve the microprocessors or software of the CMM or machining centers or what use these machines make of the repeatable trigger signal from the touch probe. Rather, it is the structure of the mechanical parts of the touch probe, and the way these parts function and interact together to produce such a highly repeatable signal, that are at issue. Tr 521; DX 987, Bates No. 011340; Stiftung v. Renishaw PLC, 945 F.2d 1173, 1177-78 (Fed.Cir.1991) (hereinafter “Zeiss ” litigation). 20. CMMs generally operate in laboratory-like environments that are dry, clean, quiet, and vibration free. Tr 1064. Machining center environments, on the other hand, are generally harsh, dirty, and wet. The touch probe may be exposed to vibration and shocks, streams of liquid coolant, and chips of metal generated by cutting operations. Tr 204-05,1026-27,1064-65. 21. Prior to Mr. McMurtry’s invention of the omnidirectional touch trigger probe, the metrology and machine tool industries utilized either hard probes, relatively complicated analog probes that were used for tracing operations, or probes that permitted stylus deflection in only a limited number of directions. Tr 117-19, 341, 343-45. 22. Hard probes are simply rigid styli mounted on the end of a movable arm of a CMM. An operator would manually move the arm holding the stylus until the stylus contacted a workpiece. Then, while the stylus was held against the workpiece, the operator would instruct the machine to take a reading of the position of the movable arm, thus determining the position of the surface of the workpiece. These hard probes required constant operator control to accomplish measurement, thus effectively eliminating the possibility of automation. In addition, damage to the probe or the workpiece could result if the probe collided with the workpiece with sufficient force. Moreover, because hard probes could deflect the part being measured, the measurements taken with hard probes were prone to errors. Tr 117-19, 341. 23. Analog probes were also designed to be mounted on the end of a movable arm of a CMM. Analog probes have a stylus that is movable relative to the probe housing. An analog probe outputs an electrical signal that is proportional to the amount of displacement of the stylus relative to the probe housing. Such probes were slow, complex, expensive, unreliable, and many were operable in only a single deflection direction. Tr 118, 341. 24. None of the devices that existed prior to Mr. McMurtry’s invention allowed cost-effective, rapid omni-directional position measurements to be taken. Many prior art devices did not permit the stylus to deflect large amounts after contacting the workpiece (known as “overtravel”). Overtravel is essential for automated systems because such systems cannot immediately stop movement of the probe (or workpiece) upon output of the trigger signal. Tr 113-15, 536. 25. In 1972, David McMurtry was a design engineer working at Rolls-Royce on the development of the Concorde jet engine. Mr. McMurtry was using a CMM equipped with a hard probe to measure delicate fuel system pipes used in the jet engine. Mr. McMurtry was experiencing a problem with use of the hard probe because contact between the hard probe and the fuel pipes would deflect the fuel pipes to an extent that the measurement became inaccurate. Tr 340-341. 26. To solve this problem, in 1972, Mr. McMurtry invented and built the first omnidirectional touch trigger probe, which was similar to the ones shown in Figures 1-3 of the '998 and '275 patents (see App. A). Tr 340. 27. The probes invented by Mr. McMurtry include a stylus-holding member that is movable omnidirectionally with respect to the probe housing. The probe is mountable on a movable arm of a machine tool or CMM that includes a computer for monitoring the position of the arm, and hence the probe. The computer of the CMM or machine tool uses the trigger signal to determine the position of the surface contacted by the stylus tip. Tr 113-15, 340 — 45, 533-34. 28. After inventing the first design of a touch trigger probe, Mr. McMurtry went on to invent additional alternative embodiments in 1972-1973. Tr 340, 346; PX 107, 108. 29. Because very little force was required to deflect the stylus of Mr. MeMurtry’s new probe, the part being measured was not deflected or damaged. In addition, unlike prior art electronic probes, the stylus was deflectable omnidirectionally to provide an electronic trigger signal. Tr 340-45. 30. Mr. McMurtry’s invention of the omnidirectional touch trigger probe allowed rapid, highly accurate measurements to be taken with a relatively simple and inexpensive probe. In addition, because Mr. McMurtry’s probes allowed for generous amounts of over-travel, the probes could be used in completely automated processes. Tr 113; PX 335 at Bates Nos. 368-375. 31. After inventing the omnidirectional touch trigger probe, Mr. McMurtry teamed up with a colleague at Rolls-Royce, Mr. John Deer, and the two formed a company to make and. sell touch trigger probes. The company originally traded under the name Shephard & Adams, and later became Renishaw pie. Tr 346, 353-55. 32. Touch trigger probes embodying Mr. McMurtry’s invention were first introduced to the marketplace in 1973. In the years immediately following their introduction, sales of the probes grew rapidly. Probes embodying Mr. McMurtry’s invention quickly displaced hard probes and analog probes in the coordinate measuring machine industry. In addition, because Mr. MeMurtry’s touch trigger probes were highly reliable and could be used in fully automated operations, Mr. MeMurtry’s probes enabled coordinate measuring machine builders to develop a wealth of new automated products that increased the speed and accuracy of measuring. Tr 134-38,145,152, 340, 353-55, 361-62; PX 282-83, 286-91,293, 533 and 534. 33. In approximately 1977, Renishaw also began selling touch trigger probes to manufacturers of machine tools for use in the harsher machine tool environment. The machine tool industry also rapidly embraced touch trigger probes. Touch trigger probes enabled machine tool builders to develop a wealth of new automated machines that increased the speed and accuracy of machining operations. The touch trigger probe helped to spawn an automation revolution that has resulted in the fully automated machining and measuring systems that are sold today. Tr 134-38,152, 340, 353-63,1167. 34. Mr. McMurtry received a great deal of recognition for his invention of the touch trigger probe, and the subsequent development of probing and automation products. Tr 143-44, 355-60, 362-66; PX 282-83, 286-91, 293-96 and 298-305. 35. Renishaw’s sales of touch trigger probes increased rapidly since the original sales in 1973. In 1996, Renishaw sold more than 23,000 probes throughout the world, with sales of machine tool probes outnumbering sales of CMM probes. The two-man company started by Mr. McMurtry and Mr. Deer has now grown to a large multinational corporation employing more than 1,000 employees. Tr 134r-38, 144-45, 362-66; PX 533 and 534. B. The '998 and '275 Patents — Renishaw’s Rest Position, Signal Upon Contact Touch Probes 36. The touch trigger probe Mr. MeMurtry invented in the early 1970’s for use in his work as an engineer for Rolls Royce eventually resulted in two U.S. patents, the '998 and '275 patents. Tr 339-41; DX 290, Bates No. 006132. 37. The '998 and '275 patents are part of the same family of patents. Both patents are based upon the same disclosure and contain identical specifications and figures. PX 335, 336. 38. The '998 and '275 patents disclose seven embodiments of touch probes which are designed to provide a signal when the stylus of the touch probe contacts an object. DX 954, Bates No. 012727. All the embodiments contain structure for repeatedly and accurately defining a “rest position” for the stylus and “movable member” of the probe, for reliably and immediately detecting a departure from that “rest position,” and for returning the movable member to the “rest position”. Id. The term “rest position” appears in the patents in suit hundreds of times. Tr 625. Renishaw sometimes refers to the “rest position” as “mechanical zero,” the “zero position” or simply “zero.” Tr 256-57, 399, 656. 39. Although the term “rest position” was not added to distinguish the claims of the '998 and '275 patents from prior art references, during prosecution of the '998 and '275 patents, the patent applicant repeatedly stressed the fundamental importance of ensuring that the stylus of the touch probe positively and accurately returns to its unique rest position or zero position: a. The accuracy of the subject probe arises essentially from the way in which the stylus is seated on convergent surfaces. This ensures that the stylus is positively and accurately seated in the zero position____ As regards the accuracy of seating, this has been measured by a repeatability test in which the stylus is displaced and allowed to return to zero a large number of times, the zero position attained after each displacement being compared with the original zero position. Using a laser test instrument, it has been found that the probe has a repeatability tolerance -of one millionth of an inch (0.000001 inch) [i.e., 0.025 micron]. PX 334, Bates No. 000581 [Remarks, Amendment filed Oct. 7, 1976 in the '634 application, p. 6,1. 20-31]. b. It is the cooperation between the bias means, the convergent surfaces on one of the members and the member engaging the convergent surfaces which assures that the movable member will be positively held in its rest position when no force is acting on the movable member. These same elements cooperate to assure that the movable member is restored to its rest position after a force has been applied to the movable member and then removed. PX 335, Bates No. 000310 [Remarks, Amendment filed Jan. 16, 1978 in the '139 application, p. 13,1.16-23], c. It is fundamental to the invention that one of the movable or fixed members is caused by the bias means to slide on the convergent surface of the other part into a position in which all these surfaces are engaged. In this way a positive uniquely defined rest position is attained. PX 335, Bates No. 00310 [Remarks, Amendment filed Jan. 16, 1978 in the '139 application, p. 13,1. 24-28], d. [T]he problem to which the present invention is addressed is ... one ... of positively locating a stylus. PX 334, Bates No. 000567 [Remarks, Amendment filed Feb. 3,1976 in the '634 application, p. 6, 1. 25-27]. e. There is no suggestion in Melvin, Jr., that this rest position of the structure 11 need be positively defined and in view of the clearances it cannot be positively defined. In any ease it cannot be said that the springs 37 urge the structure into contact with any surfaces, convergent or otherwise with a view to positively defining a rest position for the structure 11. PX 335, Bates No. 000312-13 [Remarks, Amendment filed Jan. 16,1978 in the '139 application, p. 15,1. 28 — p. 16, 1. 4 (distinguishing a prior art reference cited by the Examiner)]. f. The convergent surfaces ensure that the single movable part is located in the required rest position positively and without the possibility of mechanical slack; yet it is displaceable omni-directionally. One has to handle the probe to appreciate the ease in which the stylus can be displaced and the positive action with which the stylus returns into the rest position after a displacement. The convergent surfaces are therefore the basis of the merits of the probe. PX 335, Bates No. 000374-75 [Remarks, Declaration submitted with Supplemental Amendment filed Jan. 20, 1978 in the '139 application ¶ 17]. g.[T]he stylus must be mounted in such a way that it is accurately reseated if it has been displaced from its rest position. PX 336, Bates No. 000033 [Remarks, Amendment filed Apr. 18, 1979 in the '139 application, p. 8,1.14-16]. 40. The accuracy of measurement for the Renishaw patent touch probes is keyed to the rest position of the touch probe’s stylus, Tr 442, 853-58,1312. 41. In a preferred embodiment (which is also the basis for Renishaw’s commercial probes), a mechanical structure which includes three rods and three pairs of balls supports the stylus in the required rest position. Tr 643-45, 350, 381-83, 1305-07. As illustrated in Figures 1-3 of the '275 patent (see App. A), the rods (4) are rigidly connected to the stylus or movable member, and extend out in the form of a tripod. Each leg of the tripod rests in the V-shaped crevice formed between a pair of balls (9 and 10). Tr 1305-07; DX 1134; '275, Fig. 3, col. 2, 1. 33-46. 42. This configuration, called a “kinematic support” or “kinematic mount” by Renishaw, has been well-known for over a century for its ability to provide extreme precision and stability. Tr 303, 383-84, 1305-06, 1339; DX 1060, p. 38-39 (p. 8-9 of translation); '904, col. 1,1. 31-36. 43. Renishaw’s “kinematic mount” is also known as a “Boys joint” kinematic clamp. Tr 1305-07; DX 1060, p. 38-39 (p. 8-9 of translation). The name arises from its inventor, Sir Charles Vernon Boys, a 19th century physicist. DX 1092. The Boys joint provides a stable and extremely repeatable support for the stylus of the Renishaw patent probes. Tr 388, 1303-08; DX 1060, p. 38-39 (p. 8-9 of translation), 1101. 44. Any object can have at most six degrees of freedom of movement. With respect to the well-known “x-y-z” Cartesian coordinates, it can have an x translation (move left and right), y translation (move back and forth), z translation (move up and down), x rotation (cartwheel back and forth), y rotation (cartwheel left and right) or z rotation (spin like a top). All movement can be described in terms of one or a combination of one or more of the above movements or “degrees of freedom.” Tr 1299-1301; DX 1122. 45. A body can be prevented from moving in one or more degrees of freedom by application of constraints. The word constraint has a definite meaning in kinematic design. Tr 677-78,1400; DX 1148, p. 309,1. 13-18. Where there is physical contact between objects, there is constraint. If the objects are not in contact, there is no constraint. Tr 673, 677-78, 1301, 1400; DX 1148, p. 306-10,1149, p. 194-200. 46. An example of a constraint of a single degree of freedom is a ball resting on a flat surface. Tr 1301-02. An example of three degrees of freedom constrained is a ball sitting on three points of contact. Tr 1302-03. A kinematic equivalent of three such constraints is a ball sitting in a cone. Tr 1315-1316. 47. When an object is completely supported in a kinematic manner, all six of the degrees of freedom are constrained against movement. In such “kinematic clamps,” the number of points of contact equals the number of degrees of freedom constrained, that is, six. Tr 1304-05; DX 1120. 48. As shown in Figures 1-3 of the '998 and '275 patents, a spring (5) presses, or “biases,” the three tripod legs or rods (4) against the she balls (9 and 10), which rest on the floor of the probe housing. Tr 645; '275, col. 2, 1. 33-46. The “kinematic mount” rigidly supports the stylus at precisely six points of contact, two at each leg of the three-legged tripod. These six points of contact provide constraint of the six degrees of freedom and secure the unique and extremely repeatable rest position for the stylus of the Renishaw probes. Tr 419; '904, col. 1,1. 29h14 49. Renishaw’s kinematic mount probes return the stylus to its rest position with extreme accuracy. As earlier mentioned, Renishaw has reported to the U.S. Patent and Trademark Office (the “PTO”) repeatability tests for return of the stylus tip to its rest position to be one millionth of an inch. PX 334, Bates No. 000581. Renishaw has reported a rest position repeatability in commercial probes of less than 0.1 of a micron. Tr 387; DX 1060, p. 39 (p. 9 of translation). These reported variances are extremely small; indeed, they are negligible when compared to the accuracy of the touch probes themselves, which are typically on the order of 1 micron. Tr 1311. 50. Marposs’ technical expert, Dr. Daniel DeBra, explained that the reported variation in the rést position of the Renishaw probes is a very small fraction of the accuracy to which the probe is designed to measure and therefore the rest position is appropriately referred to as a single position. Tr 1311. 51. With real world materials and manufacturing, no rest position is perfectly precise. Because the variance of the rest position of the Renishaw probe is negligible compared to the accuracy required of the probe, however, one of ordinary skill in the art would consider it to be a single, precise, repeatable position. Tr 1311; PX 334, Bates No. 000581. 52. Renishaw, on the other hand, points out that certain of the patent figures in the '275 patent are not constrained in all six degrees of freedom and therefore, in theory, may have somewhat less precise rest positions. Tr 350-52. 53. For instance, the embodiments of Figures 4-8 of the '275 patent (see App. A) disclose probes where rotation about the vertical axis of the probe is not constrained, leaving only the other five degrees of freedom constrained. Tr 1488-89,1512. In particular, three spheres 31-33 attached to the bottom of the housing limit axial and some rotational movements of the movable member, while other spheres limit lateral movements. A pin 46 attached to the housing extends into a bore 47 in the movable member with a clearance 48 to limit rotation of the moveable member around the housing axis. As a result, the touch trigger probes shown in Figures 4-8 have a larger tolerance on the precision of the rest position than those of Figures 1-3. Tr 346-48, 351, 1182-83,1487-91. 54. However, the vertical symmetry of the probe in the embodiment of Figures 4-8 causes the probe to be insensitive to variation in rotation about the probe’s vertical axis. Tr 1512-14. Simply put, with- a straight stylus, there will be nothing to cause the stylus to spin, and even if it does, the effective position of the center of the stylus tip will not change because it is round. More importantly, to the extent that the variance in the rest position of these embodiments might increase due to the absence of the z-axis rotational constraint, it still remains a rest position probe because any increase in the rest position variance will be matched by a corresponding decrease in the probe’s accuracy. In other words, any greater variation in the return to the rest position will still be negligible when compared to the accuracy of the particular embodiment. Thus, the probe’s rest position remains a single, precise, repeatable position. Tr 400, 1309,1311, 1512-14. 55. Renishaw also suggests that Figure 8 of the '275 patent includes a tolerance with respect to the “close fit” between the curved ends of the movable member and the inside wall of the housing at 70. Tr 348, 542-43. This contention, however, was previously contradicted by Renishaw and its expert, Dr. Duffie, who told this Court the exact opposite in the Valeron litigation. 56. In the early 1980s,- Renishaw and Rolls Royce (then patent co-owners) brought suit against GTE Valeron for, among other things, infringement of the '998 patent. The suit involved claim 15 of the '998 patent. PX 107. See Rolls-Royce Limited and Renishaw PLC v. GTE Valeron Corp., 625 F.Supp. 343 (E.D.Mich.1985), aff'd, 800 F.2d 1101 (Fed.Cir.1986) (hereinafter “Valeron” litigation). 57. Dr. Duffie testified in Valeron that in order to have a constraint there must be no gap. Tr 652-54, 676-78; DX 1148,1149. He further testified that there was no gap in Figure 8. Tr 653. Renishaw submitted post trial findings to Judge Gilmore indicating that the surfaces shown in Figure 8 were in “direct engagement,” DX 954, p. 8, and the court made a specific finding of no gap and a friction fit for Figure 8 on the basis of the testimony of Dr. Duffie. Valeron, 625 F.Supp. at 349. 58. Even if this Court permitted Renishaw to change its position with respect to Figure 8 in this case, any resulting theoretical increase in the variation of Figure 8’s rest position would again be matched by a corresponding decrease in the probe’s accuracy. Thus, the probe’s rest position would still be properly considered a single, precise, repeatable position. Tr 1311,1514. 59. Similarly, the embodiments of Figures 11-14 of the '275 patent (see App. A) disclose a probe wherein the possibility exists that an electrical contact may create a condition of overconstraint. Tr 352. In particular, the hairpin spring 5 for limiting rotation of the movable member about its axis is less precise than the mechanism shown in Figures 1-3. In addition, Figure 14 incorporates an electrical contact 110 that would result in the movable member not fully contacting all of the inclined needle rollers (an overconstrained condition), causing some stylus tilting. As a result, the embodiments shown in Figures 11-14 would also have a greater tolerance on the precision of the rest position than those of Figures 1-3. Tr 348-50, 352, 396-98, 647-48,1493-95. 60. Where such an overconstraint condition exists, however, either the contact itself, or one of the elements of the seating, will be rendered ineffective, leaving six degrees of freedom constrained. Tr 1514-16. Moreover, to the extent that the variance in the rest position of this embodiment increases due to the “extra” contact, it still remains a rest position probe because any increase in the rest position variance will be matched by a corresponding decrease in the probe’s accuracy. Thus, the probe’s rest position remains a single, precise, repeatable position. Tr 639, 1311,1514-16. 61. In short, all of the embodiments shown in the '998 and '275 patents have single, precise, repeatable rest positions and there is nothing in the specification, figures or claims to indicate otherwise. Tr 408, 638-39, 860; DX 945, Bates No. 012727. 62. In Renishaw’s commercial probes, and in several of the embodiments of the patents in suit, signaling is provided by an electric current running through all of the balls (9 and 10) and rods (4). '275, Fig. 2, col. 2, 1. 60 — col. 3, 1. 6. The instant that contact with the object to be measured begins to move the stylus away from its precise “rest position,” one or more of the rods begins to move out of engagement with its associated pair of balls and the electric current is affected, thus providing a signal. Tr 1308; '275, col. 3,1.1-6. After the probe is moved away from the object, the coil spring returns the stylus to its “rest position” with extreme repeatability and precision as a result of the “kinematic mount” arrangement. Tr 388-89, 1310-11. 63. In the embodiment shown in Figure 14 of the '275 patent, an electrical contact that is separate from the seating elements is located on the fixed member such that deflection of the movable member also breaks an electrical circuit to provide a trigger signal. Tr 343, 349-53. 64. The 1998 and '275 patents disclose other potential signaling devices, including fluidic, optical projectors and other known switches. '275, col. 7,1.10-18. Regardless of the type of detector employed, the common thread is that the signal is provided as soon as possible upon contact with an object. Tr 386. 65. Although the patent applicant never argued that the claims were allowable over the references of record because the signaling means provides a position indicating signal at the instant of contact, in the prosecution history of the '275 patent, the applicant explained that the probes were “for determining the exact point at which contact is established between a stylus, and an object to be measured.” PX 334, Bates No. 000579. Test results cited to the PTO showed displacements of 0.0001 of an inch triggered a signal. Id. at Bates No. 000582. Mr. MeMurtry acknowledged that all of the patented probes are designed to trigger as soon as practically possible after contact and that any delay in signaling is a negative in the error budget for Renishaw probes. Tr 420-21. 66. In the latter 1980s, Renishaw and Carl Zeiss Stiftung brought suits against one another in the Southern District of New York regarding, among other things, Zeiss’ infringement of Renishaw’s '998 and '275 patents. The involved claims were claims 2 and 15 of the '998 patent and claims 1 and 3 of the '275 patent. See Carl Zeiss Stiftung v. Renishaw PLC, 945 F.2d 1173 (Fed.Cir. 1991) (hereinafter “Zeiss ” litigation). 67. The preamble claim language “for providing a signal when said stylus engages said object thereby indicating the position thereof’ was subject to judicial scrutiny in the Zeiss litigation. Renishaw admitted that the signal was provided “when the stylus engages the object” and that the claim language imposed “a requirement that a stylus/object engagement-position be indicated.” DX 986, 1140. The Federal Circuit, while noting that there is no signaling device disclosed in the '998 specification that is activated immediately upon contact of the stylus with the workpiece prior to the stylus being deflected, nonetheless stated that the coordinates of the stylus tip “at the point of contact” are recorded and that it was “crucial” that the probe signal “as quickly as possible when the stylus makes contact.” The Federal Circuit further noted that “reading the specification makes clear that ‘thereof ’ [in the claim language] must refer to the position of the stylus (which moves) when it contacts the object, not the position of the object (which remains stationary).” 945 F.2d at 1174-75, 1177 n. 2 (first emphasis added). 68. In the second family of Renishaw patents, Mr. MeMurtry reiterated that when the stylus of the '998 patented probe contacts a workpiece, a trigger signal is generated by the probe, producing a reading of the instantaneous position of the stylus. “Because of the repeatability of the stylus rest position, this is an accurate measure of the position in space of the point of contact between the stylus and the workpiece.” '904, col. 1,1. 28-42. 69. In Valeron and Zeiss, both Renishaw and its technical expert, Dr. Neil Duffie, confirmed the well understood meaning of the term “rest position” as used in the patents and the fundamental importance of the rest position to the operation of Renishaw’s patented probes. DX 945, p. 106-07, 954, p. 5-6, 965, p. 869-70. Q. — What does the term “positively defined rest position” mean to you? A.- — It means there is only one. Q. — One what? A. — There is only one position in which the stylus can exist when no force is applied to deflect it. Q. — What happens when a force is applied to deflect it? A. — There is a tendency to move the stylus out of its rest position away from its rest position. Q. — And upon cessation of that force, where does the stylus end up? A. — It comes back exactly to the rest position. Q. — And its (sic) that ability of the probe that gives it accuracy? A. — Yes, sir, that is one of the major accuracy contributions in this device. DX 945, Valeron, p. 107,1.1-12. Q. — What if anything is the most important aspect of a touch trigger probe? A. — The most important aspect I would say is its ability to accurately seat in a positively defined, accurate, known position and be able to move in and out of that position and obtain the same level of accuracy each time that cycle occurs. DX 965, Zeiss, p. 868,1. 24 — p. 869,1. 5. 70.Dr. Duffle further confirmed how the accuracy of the Renishaw patent probe is inextricably tied to its rest position: Q. — What would be the effect of having an unrepeatable rest position for a stylus in the touch trigger probe? A. — It would have a corresponding impact, decrease inaccuracy (sic). However much uncertainty there was in where the probe stylus returned, that would immediately add that much uncertainty in the measurements being taken on the object. Q. — Could that uncertainty be eliminated by increasing the immediacy of signaling? A. — I don’t believe so. Q. — Why not? A.' — Because by definition the uncertainty is unpredictable. So since you could not know where you were you could not predict where you were, therefore, you could not use any means to try to improve that measurement. Q. — Can you further explain that in connection with the concept of repeatability? A. — Well, it’s really the same thing. Repeatability refers to — if you repeat some operation, whether it’s the triggering of the probe against an object or the constant reseating of the seats, it refers to accuracy with which this stylus tip comes back to exactly the same point. If it doesn’t come back to exactly the same point, then you don’t know where the tip is when you trigger it. DX 965, Zeiss, p. 869, 1. 14 — p. 870,1. 12. C. Problems With The '998 and '275 Patent Technology 71. In the 1980’s, certain less desirable characteristics of Renishaw’s probes designed according to the '998 and '275 patents began to be noticeable. These problems included (1) “lobing” and (2) occasional failure to reseat (“hysteresis”). '904, col. 2, 1. 1-7, 33-35. 72. During probing operations, the stylus of a touch probe will bend very slightly upon contact with the workpiece. Although styli are typically made of steel or ceramic materials, even these extremely rigid materials are not infinitely rigid and will bend. Although this bending is extremely small, at the precision standards expected of touch probes, any variation in this bending can adversely affect the accuracy of measurements. Tr 452-55, 1354; '904, col. 2,1. 6-24. 73. Because of the triangular structure of the “kinematic mount” of the '998 and '275 patent touch probes, the stylus will bend a different amount depending on different directions of contact. If the amount of bending in each direction is plotted, a triangular, three-lobed pattern will result. Variation in stylus bending depending on direction of contact is known as “lobing.” Tr 452-55, 1354; '904, col. 2,1.15-21; DX 1136. 74. Frictional forces can also occasionally affect the precise reseat position of the “kinematic mount” of the '998 and '275 patent touch probes. Tr 1354-56. This behavior is referred to in the Renishaw patents as “hysteresis upon reseat.” '904, col. 2, 1. 33-35. Friction between the rods and associated ball pairs may cause one or more of the rods not to seat fully in the convergent surfaces of the ball pair. Tr 865, 1354-56; '904, col. 2, 1. 35-38. 75. The degree to which a re-seating error is a problem depends on the orientation of the error. Because of the length of the stylus, certain types of re-seating errors are magnified. For example, a “sideways” or lateral error of 0.3 of a micron at the kinematic mount will cause a lateral error of 0.3 of a micron at the stylus tip. This error is not magnified. However, a “tilting” or vertical error of 0.3 of a micron at the kinematic mount will result in a lever effect due to the length of the stylus, thus magnifying the error of 0.3 of a micron to an error of about 0.9 of a micron or more at the stylus tip. Since it is the tip of the stylus that contacts the workpiece, the lever effect and magnified error in the Renishaw probes can result in an error in the rest position of the stylus tip and thus contribute to an error in the measurement. This is particularly problematic when probing curved, beveled or inclined surfaces. Tr 370-74, 458-60, 539-40, 865-67, 1354-56; DX 1138. 76. Moreover, in a limited number of applications, certain of Renishaw’s commercial touch trigger probes made in accordance with '275 patent Figures 1-3 experienced false triggering when used in certain high vibration environments. Tr 149, 317. D. The '691 Family of Patents 77. David McMurtry, the inventor of the '998 and '275 patent probes, addressed the twin problems of lobing and hysteresis in a second family of Renishaw patents, specifically the U.S. Patent No. 5,146,691 (the “'691 patent”), the '428, '514, and '904 patents. Tr 492, 864. 78. The first patent application to be filed by Renishaw for the subject matter of the '691 patent was filed February 23, 1990 as a United Kingdom patent application. PO 15. 79. The corresponding U.S. patent application was filed February 25, 1991, which subsequently issued as the '691 patent. PO 15. Thus, the original disclosure of Mr. McMurtry’s improvement patent occurred before Renishaw first obtained a Marposs MIDA probe in July of 1992. Tr 240-41; DX 247. None of the claims of the '691 patent were ever asserted by Renishaw against any Marposs probe. Tr 783-84, 437-38. 80. After learning of the Marposs MIDA probes, Renishaw pursued a series of continuation applications from the '691 patent. Tr 436-38; DX 1150, p. 9-12. Generally, a continuation application contains the exact same disclosure, specification, and figures of the original patent. The only thing that changes is the claims. Tr 721-22. Both Mr. McMurtry and Renishaw’s U.S. patent counsel acknowledged that their purpose in pursuing these continuation applications was to attempt to write claims that could be asserted against the Marposs MIDA probes. Tr 438-39; DX 1150, p. 18-20. 81. Three U.S. patents resulted from these continuation applications; specifically the '428 patent issued on October 19, 1993, the '514 patent issued on October 11, 1994 and the '904 patent issued on February 20, 1996. All three continuation patents were asserted against Marposs in this litigation, although no representative claims were chosen from the '428 patent. PO 1. 82. All of the patents in the '691 patent family have the exact same specification and figures, with the exception of the '904 patent, where three paragraphs were added to the summary of the invention at the request of the Patent Examiner. DX 1150, p. 73-78. At the time of -the original disclosure of the '691 patent family, no prototype or other physical device was created by Mr. McMurtry. Tr 482. Rather, the invention involves Mr. McMurtry’s ideas for improving on the '998 and '275 patent probes. Tr 482. 83. The '691 family of patents can be understood with reference to the embodiment shown in Figures 1 and 2 of the '904 patent (see App. B). 84. The stylus is supported by two independent supports. Tr 883; '904 col. 3, 1. 7-16. The first is the axial constraint. In the axial constraint, an inverted cup (stylus holder 12) rests on the floor 20 of the probe housing 10. The stylus 14 is rigidly connected to the eup. The cup resting on the floor of the housing provides a precise axial rest position for the stylus holder and depending stylus. Tr 1357; '904 col. 3, 1. 65 — col. 4,.l. 5. Because the stylus holder has a circular, rather than triangular, shape, lobing was expected to be virtually eliminated. Id. at col. 4,1. 62 — col. 5,1. 2. It was also expected that “hysteresis” would be reduced by very carefully matching the confronting surfaces of the skirt of the stylus holder and the floor of the housing. This would, in theory, minimize any “up and down” or “tilting” re-seating irregularities of the stylus holder. Tr 477-78, 875-78, 1364. Hysteresis is also reduced by reducing the force (and thereby reducing the friction) holding the skirt and the floor of the housing together. In the Figure 1 embodiment, this is achieved by prestressing the planar spring 30 against the action of the biasing spring 24. In other embodiments, two biasing springs are employed, one with lower force than the other. Tr 906, 1385; '904 col. 4, 1. 40-51, col. 5, 1. 7-19, col. 7, 1. 50-57, col. 8 1. 45-49. 85. The second independent support is the lateral constraint, consisting of a traditional Renishaw kinematic mount (34 and 36) attached to a ring 32. A diaphragm-like planar spring 30 is secured at its outer edges to.the ring and centrally to the stylus holder 12. The planar spring, in combination with the kinematic mount, holds the stylus holder and depending stylus in a precise lateral rest position. Tr 479-80, 886, 1358, 1368; '904, col. 4,1. 6-24. 86. The combination of constraints provides a precise axial rest position and a precise lateral rest position, which holds the stylus in a single, precise, repeatable rest position, with all six degrees of freedom constrained. Tr 1361, 883, 943-44; '904, col. 4, 1. 25-27. 87. In operation, according to the teachings of the '691 patent family, when the stylus of the touch probe contacts the workpiece, the stylus holder immediately tilts about a point on the stylus holder’s skirt at the floor of the housing. Tr 882. This initial tilting is accommodated by flexure of the planar spring, allowing the elements of the kinematic mount to remain engaged. Tr 480, 919; '904, col. 4, 1. 52-58. At the instant of contact and tilt, a light beam projected through a hole in the stylus holder is impinged, or one of the alternate detection schemes is triggered, and a signal is sent to the measurement system. The signal always occurs at the initiation of tilting, as close as possible to the instant of first contact when the stylus is in its rest position, and always while the kinematic mount is still engaged. Tr 483-84, 494,1387. 88. The design of the '691 patent family thus isolates the triggering event from any movement of the kinematic mount. Tr 484, 493, 1387. In theory, this tends to insulate the signaling caused by the initial tilting of the stylus holder and the return of the stylus holder to its rest position, from the lobing and hysteresis problems that accompanied Renishaw’s traditional kinematic mount probes. Tr 905-06, 493-94, 1385; '904, col. 4,1. 62 — col. 5,1. 2. 89. Additional movement of the stylus after a signal is generated is called “overtravel.” In the '691 family of patent probes, further overtravel is accommodated by the disengagement of the kinematic mount. Tr 495, 920. This disengagement protects the relatively delicate' planar spring from damage. Tr 1358-59; '904, col. 9,1. 22-30. 90/ As the probe moves away from the workpiece, the stylus holder returns to its rest position. The elements of the kinematic mount first re-engage, then the tilting of the skirt on the floor of the housing decreases until the skirt is fully re-engaged with the housing and the stylus holder and depending stylus assume a single, precise, repeatable rest position. '904, col. 5,1. 3-7. 91. Although their mechanical configurations vary slightly, all of the embodiments of the '691 family of patents operate on the same principles. All have a stylus holder and stylus that is fully constrained by a combination of two independent supports, an axial constraint and a lateral constraint. Tr 494, 872-75, 883-84. 92. The axial constraint in each of the embodiments is achieved by abutting surfaces, either annular rings abutting flat surfaces or, with respect to the Figure 10 embodiment, three balls or a ring of balls resting on a flat surface. Tr 494, 880-81. The axial constraint in each embodiment constrains z-axis translation and x — and y-axis rotation. Tr 873-74, 1361. 93. The lateral constraint is in each instance achieved through a combination of a kinematic mount combined with a planar spring. Tr 874,1361. The lateral constraint in each embodiment constrains x — and y-axis translation and z-axis rotation (the planar spring, a flexure, transmits only those three of the six constraints afforded by the kinematic mount). Tr 874,1358,1361. 94. Thus, in each and every embodiment in the '691 patent family, all six degrees of freedom are constrained in order to provide a precise rest position. Tr 874-75, 1361. This precision is characterized as an improvement upon the prior '998/'275 touch probes, which improvement is achieved by reducing hysteresis and avoiding the tilting and error magnification that occurs due to the occasional failures of the '998/'275 patent probes to re-seat. Mr. McMurtry acknowledged that one of his objectives was to improve upon the rest position by reducing as much as possible the hysteresis causing errors in the rest position. Tr 459-60. 95. In the Figure 7 embodiment of the '904 patent (see App. B), hysteresis caused by friction between the cylinders 92 and balls 90 will cause the stylus holding movable member to tilt relative to the housing 88. Thus, the embodiment shown in Figure 7 suffers from greater hysteresis than the Figure 1 embodiment, resulting in a less precise rest position. Nevertheless, because the Figure 7 embodiment signals by tilting about points on annular surfaces, it has improved lobing characteristics. Tr 457-61, 492, 967. 96. Like the '275 patent probes, all of the '691 family of patent probes are signal-on-contact probes. The specifications unambiguously provide that the probes are designed to detect “the instant at which the stylus tip first-contacts a workpiece.” '904, col. 6,1.10-11. All of the various arrangements for detection, including piezo-electric detectors, strain gauges, electrical circuits, and photoelectric are intended for “detecting the instant of contact between the stylus tip and the workpiece.” '904, col. 9,1. 16-19; Tr 494, 907. 97. In all cases, the signaling structure is completely separate from the kinematic lateral movement constraining seating structure, thus reducing lobing. Although some of the disclosed signaling mechanisms are relatively quick, none provides a trigger signal at the absolute instant of contact of a stylus with an object. Tr 372-73, 621-22, 903, 1253, 1457-58; PX 499, col. 6, 1. 18-25. 98. While it is of course true that the laws of nature dictate that no detection device can be “absolutely instantaneous,” the claims, specifications, figures, and Mr. McMurtry’s testimony confirm that the patented probes signal as soon as possible when the stylus tip contacts the workpiece. The quicker the Renishaw probes trigger, the better their performance. In short, the patents teach the quickest signaling possible, and there is no suggestion otherwise. In fact, Mr. McMurtry stated that he taught good probes with quick signals, and “wouldn’t do anything but that, but to teach the best.” Tr 386,484, 850-53, 904. 99. For the '691 family of patent probes, a delayed signal would also defeat a major objective of the invention, which is insulating the signaling from the effect of disengagement of the kinematic mount. If a signal was delayed, the kinematic mount would disengage before the signaling and the probe would again be susceptible to hysteresis and lobing. Tr 484,1387. 100. Renishaw never commercialized the '691 family of patents. Renishaw now sells an electronic filter, which it claims is more cost effective, for dealing with false triggering situations and a new strain gauge probe which reduces lobing. Tr 146-151. E. The Accused MIDA Probes 101. In the 1980s Marposs marketed a touch trigger probe known as the A-Seriés probe. PX 506. That probe was introduced to the United States in 1986. The A-Series probe did poorly in the marketplace because it was too complex and costly, did not have sufficient overtravel, could not be made in small sizes, and generally did not perform as well as Renishaw’s probes to be successful. Tr 1034-37, 1156-64, PX 20 at Bates Nos. 1050115-17 and 1050129-32, PX 113. 102. Mr. Possati, the president of Mar-poss, was unhappy with the lack of commercial success of the A-Series probe, and accordingly called a meeting in September 1989 to initiate development of a competitive machine tool probe. Mr. Possati set up a working group consisting of himself, Mr. Danielli, Mr. Dall’Aglio and Mr. Miniucchi, with himself as the coordinator. Tr 1156, 1163-64; PX 20 at Bates Nos. 1050115-17 and 1050129-32. 103. By the time the Mida project got underway in September 1989, Marposs was already aware of the internal structure of Renishaw’s LP and MP machine tool probes and had reviewed written descriptions of Renishaw’s machine tool probes. Marposs knew that those probes contained three elements spaced 120° apart and resting in three pairs of balls forming a convergent surfaces kinematic mount. At the commencement of the MIDA project, Marposs also reviewed the results of tests of Renishaw machine tool probes, and those test results were subsequently utilized to evaluate the performance of the prototype MIDA probes. Marposs also reviewed Renishaw’s '998 and '275 patents, and knew that they showed the use of three elements spaced 120 degrees apart and resting in pairs of convergent surfaces. Tr 1164-70, 1174-78; PX 130; PX 575, pp. 90-99,125-26. 104. Marposs allocated substantial resources to studying existing probes and probe patents, including Renishaw’s, and endeavored to design around the concepts employed by Renishaw in its '998 and '275 patents and other commercial touch probes. Tr 1027,1066-67. Marposs invested approximately two and one-half million dollars on research and development of the MIDA probes. Tr 1084. 105. From this study, Marposs learned that nearly all touch trigger probes, including Renishaw’s patented and commercial probes, utilized the same basic operational principle. Tr 1066-67. The principle was to establish a rest position for the probe’s stylus, and to signal on contact between the stylus and object, thus producing a signal that is an accurate measure of the point of contact. Tr 442, 852-53, 902, 1067. Essential to this principle is that the probes have a unique, repeatable rest position in order to achieve required accuracies. Thus, the conventional wisdom in the art was that a single, precise, repeatable rest position was critical to a touch probe. Tr 1066-67, 1311-14; DX 840, col. 1,1. 29-38. 106. As mentioned supra, ¶ 76, a problem with these rest position, signal on contact type probes is that they are subject to “false triggering” in harsh machining center environments. False triggering can occur because the vibration and shocks encountered in machining centers causes sufficient displacement of the probe stylus to generate a signal even though no contact with an object has occurred. Tr 1027, 1064-65, 1068; DX 49, 71, 98. Machining center operations are often unmanned. Consequently, false triggers can result in a complete halt in operations. Tr 311-12. 107. Marposs ultimately developed a new probe technology which resulted in U.S. Patent No. 5,299,360, assigned to Marposs, and in Marposs^ launching its patented MIDA line of touch probes in 1992. Tr 1070-72, 1083-84; DX 408. Marposs subsequently developed four additional versions of the Marposs MIDA probes. PX 550-53. The MIDA line of touch probes consists of five different versions which have been sold under the designations T18, T25G, T25S, TL25, T36G, T36S, TL36G, T60G and T60S in the United States. 108. The MIDA machines tool probes are fully interchangeable with Renishaw’s commercial machine tool probes, and in many instances are identical in size and shape and fully utilizable with the same software and interfaces. Tr 159-62, 1029,1037-41; PX 20, PX 365 A, C, D, E, PX 366 A, B, D, E, PX 556 and PX 356. 109. The patented MIDA touch probes, however, provide a repeatable trigger position sometime after contact between the stylus and workpiece, without relying upon any single, precise, repeatable rest position. Tr 1069-72,1331-32. 110. Without the necessity of a rest position there was no need to constrain the stylus in a manner that resulted in a single precise repeatable rest position such as that provided by Renishaw’s kinematic mount or any other type of kinematic clamp. Instead, Marposs decided to base its new generation of probes on a simple ball and cone type support for the probe stylus. Tr 1072-74; DX 1105,1114. 111. The MIDA probe technology can be likened to a bell. In a bell, the position of the clapper within the bell is not important; it has no single, precise, repeatable position. What matters is the engagement of the clapper with the rim of the bell, which is a repeatable event. At the moment the bell rings, the clapper is at a defined and repeatable angle relative to the central axis of the bell. The stylus in the Marposs probe works on the same principle. Tr 1070-71. 112. All MIDA touch probes (see App. C) have a spherical armset to which a stylus is rigidly connected. The armset is supported by the housing through the engagement of a ball-shaped surface of the armset and a conical surface of the housing. The armset is biased into engagement with the housing by a coil spring. The armset also has a disc-shaped extension. There is a shelf in the housing that faces the underside of the disc. The disc and shelf are separated by a small, but distinct, gap measuring 1-5 microns. Tr 888, 1087, 1090-92; DX 395, 397. A precision microswitch is located directly above the armset. Tr 1077; DX 1111. In versions 2, 4, and 5, a flexible bellows is attached to the top of the armset and to the housing to prevent the armset from spinning on its vertical axis. Versions 1 and 3 of the MIDA probes had a flexible twin-lamina assembly, instead of a bellows, for the same purpose. Tr 1154, 1318, 1322; DX 1132, 1133. The fifth version is similar to the fourth version, except that the coil spring is located inside the anti-rotation bellows. Tr 558-59; PX 548 and 553. 113. In operation, when the MIDA touch probe approaches and contacts a workpiece from the side, the stylus tip will begin to deflect sideways. This initial movement of the stylus tip causes the armset to rotate about a point at its center, due to the spherical shape of the armset within the conical housing. After a period of rotation (like a ball and socket), the disc and shelf touch at a point. The surfaces of the disc and shelf were previously separated by the gap, but rotation of the armset brings them into contact. It is this point of contact between the disc and the shelf that is the repeatable event to which the accuracy of the MIDA probe is tied. Additional movement of the stylus then causes tilting of the armset about the point of contact between the disc and shelf, and the armset lifts up out of the conical portion of the housing. As the stylus continues to move, the armset continues to tilt, causing the top of the armset to rise up to contact the pin of the microswitch and then to push the pin upward. Upon sufficient movement of the pin, the microswitch generates a signal. Tr 950-51,1074-80,1330-31; DX 1122. 114. In the accused probes, the specification for the gap between the disc and the shelf was originally 1-10 microns but was later changed to 1-5 microns. Tr 1092; DX 395, 397. Renishaw does not dispute the existence of the gap between the shelf and the disc of the MIDA armset. Tr 289, 883. 115. The reduction in the gap size resulted in improved performance in measuring curved or inclined surfaces and small, deep bores. Tr 1225-30, 1235-36, 1238; PX 177, PX 362. 116. For an average three micron gap between the disc and shelf, and depending on the play in the microswitch and the length of the stylus, the diameter of the triggering points can be anywhere from 153 to 801 microns using typical stylus lengths. Tr 923; DX 1145. 117. After a signal is sent, the MIDA touch probe is moved away from the workpiece and the spherical surface of the armset and conical portion of the housing re-engage. The armset of the MIDA touch probe is not supported by a Boys joint or other kinematic clamp. It does not return to a single, precise, repeatable rest position. Instead, the armset returns to an indeterminate position. Tr 1082; DX 247. The center of the stylus tip can be anywhere at random within a circular area, which Marposs calls the “neutral zone.” The diameter of the neutral zone is determined by the size of the gap, the length of the stylus, and the radius of the disc. Tr 866, 1083-84; DX 1144. The neutral zones in the accused MIDA touch probes may range from as little as approximately 7 microns to as many as approximately 280 microns in diameter using typical stylus lengths. DX 1144. 118. Tests of MIDA probes conducted by Renishaw concluded that MIDA probes had an indeterminate mechanical zero. Tr 1325-26; DX 247,133. 119. MIDA probe versions 1 and 2 had a safety device on top of the twin lamina and bellows, respectively, opposite the armset. The safety device consisted of three balls set in the top of the housing which engaged three V-shaped grooves in a plastic or metal detent plate attached to the top of the twin lamina or bellows. The safety device, no longer manufactured, was present to protect the twin-lamina or bellows from damage during twisting of the stylus when the stylus is removed from or screwed into the armset. In such ah overtorque situation, the safety device released (like ski bindings); that is, the top plate would twist out of engagement with the balls mounted on the underside of the top of the housing, thus saving the bellows or twin-lamina from damage. Tr 1111-13,1321-22. 120. The safety device had the purpose of releasing the internal assembly from the probe housing during an overtorque (twisting) situation, not of returning the armset or stylus to any rest position and played no function during normal probing operations. Marposs ultimately discontinued use of the three ball/three V-groove kinematic mount in the more current versions 3-5 of the Mar-poss MIDA probe for several reasons. Mar-poss found it unnecessary and disadvantageous from a performance perspective, found a less costly way of protecting the internal assembly of the probe during an overtorque situation, and because of the ongoing litigation with Renishaw. Tr 1048-49, 1111-13, 1119-25, 1149-51, 1199-1200, 1202-04; PX 87, PX 362, PX 575, pp. 285-91. 121. Renishaw contends that the safety device may disengage if used with a “cranked” stylus, meaning an offset stylus shaped like a capital letter L. Tr 666-67. However, Mr. Danielli testified that the safety device probes were not intended to be used with cranked styli. Tr 1152-53, 1184-85. This fact is confirmed by Renishaw’s