UNITED STATES PATENT AND TRADEMARK OFFICE
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`LG ELECTRONICS, INC. and
`LG ELECTRONICS U.S.A., INC.
`Petitioners
`
`v.
`
`TOSHIBA SAMSUNG STORAGE TECHNOLOGY KOREA CORPORATION
`Patent Owner
`
`Patent No. RE43,106
`
`DECLARATION OF MASUD MANSURIPUR, PH.D.
`
`LG Electronics, Inc. et al.
`EXHIBIT 1012
`IPR Petition for
`U.S. Patent No. RE43,106
`
`

`

`TABLE OF CONTENTS
`
`I. 
`Qualifications, Background, and Experience .................................................. 1 
`Scope of Assignment ....................................................................................... 3 
`II. 
`III.  Materials Considered ....................................................................................... 4 
`IV. 
`Summary of Opinions ...................................................................................... 6 
`V. 
`Legal Principles Used in Analysis ................................................................... 6 
`A. 
`Patent Claims in General ....................................................................... 6 
`B. 
`Person of Ordinary Skill in the Art ....................................................... 7 
`C. 
`Claim Construction ............................................................................... 8 
`D.  
`Prior Art ................................................................................................. 8 
`E. 
`Patentability ........................................................................................... 9 
`VII.  A Person of Ordinary Skill in the Relevant Art ............................................. 13 
`A. 
`Relevant Field ...................................................................................... 13 
`B. 
`Person of Ordinary Skill in the Art ..................................................... 13 
`VIII.  Background of the Relevant Technology ...................................................... 14 
`IX.  The ’106 Patent .............................................................................................. 20 
`A. 
`The Claims of the ’106 Patent ............................................................. 24 
`B. 
`Problem Addressed by the ’106 Patent ............................................... 25 
`C.   Solution Set Forth in the ’106 Patent .................................................. 27 
`Claim Construction ........................................................................................ 30 
`X. 
`XI.  Obviousness Analysis Regarding the Admitted Prior Art and Katayama ..... 30 
`A. 
`Summary of Opinion ........................................................................... 31 
`B. 
`Summary of Admitted Prior Art .......................................................... 32 
`C. 
`Summary of Katayama ........................................................................ 38 
`D. 
`The Combination of Katayama and the Admitted Prior Art ............... 39 
`E. 
`Integration of the Diffractive Element and Objective Lens ................ 42 
`F. 
`Claim 7 ................................................................................................ 44 
`
`ii
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`

`

`“An objective lens to form beam spots of different sizes using
`i. 
`corresponding first and second light beams of respectively different
`wavelengths” ....................................................................................... 44 
`ii. 
`“an inner region including an optical center of the objective
`lens which has an optical property optimized to focus the first light
`beam onto a first optical recording medium of a first thicknesses and
`to focus the second light beam onto a second optical recording
`medium of a second thickness other than the first thickness” ............ 47 
`iii. 
`“a diffractive region surrounding said inner region and
`comprising an optical property optimized so as to selectively diffract
`the first and second light beams as a function of wavelength so as to
`change a numerical aperture of the objective lens” ........................... 49 
`G.  Dependent Claims ............................................................................... 52 
`i. 
`Claim 8 ...................................................................................... 52 
`ii. 
`Claim 9 ...................................................................................... 55 
`iii.  Claims 10 and 11 ....................................................................... 56 
`iv. 
`Claim 12 .................................................................................... 58 
`v. 
`Claim 13 .................................................................................... 60 
`vi. 
`Claims 14 and 15 ...................................................................... 61 
`vii.  Claim 16 .................................................................................... 62 
`viii.  Claim 17 .................................................................................... 63 
`ix. 
`Claim 18 .................................................................................... 64 
`x. 
`Claim 19 .................................................................................... 65 
`Secondary Considerations ................................................................... 67 
`H. 
`Claim Charts ........................................................................................ 72 
`I. 
`XII.   Conclusion ..................................................................................................... 73 
`
`
`iii
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`

`

`
`
`1. My name is Masud Mansuripur. I am a Professor of Optical Sciences
`
`and Chair of Optical Data Storage in the College of Optical Sciences at the
`
`University of Arizona. I understand that my declaration is being submitted in
`
`connection with a Petition for Inter Partes Review of U.S. Patent No. RE43,106
`
`(the “’106 patent”) (Ex. 1001).
`
`I.
`
` Qualifications, Background, and Experience
`
`2.
`
`I received a Bachelor of Science degree in Electrical Engineering
`
`from Arya Mehr University (Iran) in 1977, a Master of Science degree in Electrical
`
`Engineering from Stanford University in 1978, a Master of Science degree in
`
`Mathematics from Stanford University in 1980, and a Ph.D. in Electrical
`
`Engineering from Stanford University in 1981.
`
`3.
`
`I have authored four scientific and technical books and authored or
`
`co-authored over 250 scientific and technical journal articles; I am listed as an
`
`inventor on eight U.S. patents, of which six are directed to optical data storage, and
`
`I have over 30 years of experience with the optical data storage industry.
`
`4. While a graduate student at Stanford University from 1978 to 1981, I
`
`worked as a consultant for Xerox Palo Alto Research Center (PARC) and also
`
`worked at Xerox Research Centre of Canada as a member of research staff. At
`
`Xerox, I was involved with developing a rewritable optical disc for massive
`
`storage of digital information. After receiving my Ph.D. degree from Stanford, I
`
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`

`

`joined the College of Engineering at Boston University, where I established a
`
`research program in Optical Data Storage. In 1988, the College of Optical
`
`Sciences at the University of Arizona invited me to join their newly-established
`
`Optical Data Storage Center, which was funded by IBM, Kodak, Philips-Dupont,
`
`Siemens, and the State of Arizona. Since 1988, I have worked as a Professor of
`
`Optical Sciences at the University of Arizona, devoting my time to teaching and
`
`research in optics, optical data storage, optical communication, and several other
`
`areas of modern science and technology.
`
`5.
`
`I have been a technical advisory board member of Quinta Co., San
`
`Jose, California (1995-2000), DataPlay Co., Boulder, Colorado (1998-2002),
`
`Toptica Photonics, Munich, Germany (1999-present), NanoChip Co., San Jose,
`
`California (2003-07), and Polarizonics Co., Los Angeles, California (2005-06). I
`
`am also a member of the International advisory committee of the Instrument
`
`Technology Research Center (National Applied Research Laboratory), Taiwan
`
`(2008-present). These companies and organizations engage (or were engaged) in
`
`developing advanced optical data storage media and drives.
`
`6.
`
`I am the Founder and President of MM Research, Inc.
`
`(www.mmresearch.com), Tucson, Arizona (founded in 1995), which develops and
`
`markets simulation software for the optical data storage industry. I was the Chief
`
`Optical Scientist at Capella Corp. from 2001-02, while on a 50% leave of absence
`
`2
`
`

`

`from the University of Arizona. I have been a consultant to numerous optics
`
`industry leaders during my professional career, including IBM, Kodak, Imation,
`
`Seagate, Samsung, LG Electronics, Hewlett-Packard, DataPlay, Quinta, TeraStore,
`
`NanoChip, Read/Rite, MaxOptix, Komag, DiscoVision, Ricoh, Calimetrics,
`
`General Electric, Energy Conversion Devices, Digital Equipment Corp., Data
`
`General, and Korea Institute of Science and Technology.
`
`7.
`
`During the past 35 years, in addition to conducting extensive
`
`theoretical studies and computer simulations, I have designed and built test
`
`equipment for the optical data storage industry. Some of these instruments have
`
`been commercialized by Toptica Photonics (Munich, Germany).
`
`8.
`
`A more complete recitation of my professional experience including a
`
`list of my journal publications, patents, conference proceedings, book authorship,
`
`and committee memberships may be found in my Curriculum Vitae, attached to
`
`my declaration as Appendix A.
`
`II.
`
` Scope of Assignment
`
`9.
`
`I have been retained in this matter by Rothwell, Figg, Ernst &
`
`Manbeck, P.C. (“Rothwell Figg”) as a technical expert in the field of optical data
`
`storage and retrieval technology, including optical pickup systems for optical disks
`
`such as compact disks (CDs) and digital video (or versatile) disks (DVDs). I am
`
`being compensated for my work in this matter at my usual and customary rate. I
`
`3
`
`

`

`have no personal or financial stake or interest in the outcome of the Petition for
`
`Inter Partes Review or any related action. My compensation in no way depends
`
`upon my testimony or the outcome of the Petition for Inter Partes Review.
`
`10.
`
`I have been advised that Rothwell Figg represents LG Electronics,
`
`Inc. and LG Electronics U.S.A., Inc. (collectively “LG” or “Petitioners”) in this
`
`matter and that Toshiba Samsung Storage Technology Korea Corporation (“TSST”
`
`or “Patent Owner”) owns the ’106 patent. I have no personal or financial stake or
`
`interest in LG, TSST, or the ’106 patent.
`
`11.
`
`I have also been engaged by Rothwell Figg to assist with the pending
`
`litigation between LG and TSST.
`
`III. Materials Considered
`
`12.
`
`In forming the opinions expressed below, I considered the ’106 patent
`
`and its file history. I have also considered the following documents:
`
`(1)
`
` U.S. Patent No. 5,696,750 to Katayama (filed Jun. 5, 1996) (issued Dec.
`
`9, 1997) (“Katayama”) (Ex. 1002);
`
`(2)
`
` “Optical Pick-Up for DVD,” by Shinoda et al., IEEE Transactions on
`
`Consumer Electronics, Vol. 42, No. 3 (August 1996) (“Shinoda”) (Ex.
`
`4
`
`1003);
`
`
`
`
`
`

`

`(3)
`
`“Impact of Diffractive Optics on the Design of Optical Pick Up,” by
`
`Lehureau, Proc. SPIE 2783, Micro-Optical Technologies for
`
`Measurement, Sensors, and Microsystems, 22-29 (August 26, 1996)
`
`(“Lehureau”) (Ex. 1004);
`
`(4)
`
`“Dual Focus Optical Head for 0.6mm and 1.2mm Disks,” by Komma et
`
`al., SPIE Vol. 2338 Optical Data Storage, 282-288 (1994) (“Komma
`
`Article”) (Ex. 1005);
`
`(5) U.S. Patent No. 5,446,565 to Komma et al. (filed Feb. 1, 1994) (issued
`
`Aug. 29, 1995) (“Komma Patent”) (Ex. 1006);
`
`(6) U.S. Patent No. 5,526,338 to Hasman et al. (filed Mar. 10, 1995) (issued
`
`Jun. 11, 1996) (“Hasman”) (Ex. 1007);
`
`(7)
`
`“Effect of Aberrations and Apodization on the Performance of Coherent
`
`Optical Systems,” by J.P. Mills and B. J. Thompson, J. Opt. Soc. Am.
`
`A/Vol. 3, No. 5 (May 1986) (“Mills Article”) (Ex. 1008);
`
`(8) Fundamentals of Optics, by F. Jenkins & H. White, Fourth Edition
`
`(1976) (“Jenkins & White”) (Ex. 1009);
`
`(9) Handbook of Optics – Devices, Measurements, & Properties Volume II,
`
`by Michael Bass, Second Edition (1995) (“Bass”) (Ex. 1010);
`
`(10) U.S. Patent No. 5,349,471 to Morris et al. (filed Feb. 16, 1993) (issued
`
`Sep. 20, 1994) (“Morris”) (Ex. 1011); and
`
`5
`
`

`

`(11) U.S. Patent No. 6,556,990 to Kajiyama et al. (PCT filed Sept. 1997)
`
`(Issued April 22, 2003) (“Kajiyama”) (Ex. 1020).
`
`I have also relied upon my education, background, and experience.
`
`IV. Summary of Opinions
`
`13. Based on my investigation and analysis and for the reasons set forth
`
`below, it is my opinion that claims 7-19 of the ’106 patent would have been
`
`obvious to one of ordinary skill in the art in view of the prior art set forth in the
`
`Background of the ’106 patent and Katayama.
`
`V.
`
` Legal Principles Used in Analysis
`
`14.
`
`I am not a patent attorney nor have I independently researched the law
`
`on patentability. Rather, LG’s attorneys have explained the legal principles to me
`
`that I have relied on in forming my opinions set forth in this declaration.
`
`A. Patent Claims in General
`
`15.
`
`I have been informed that patent claims are the numbered sentences at
`
`the end of each patent. I have been informed that the claims are important because
`
`the words of the claims define what a patent covers. I have also been informed that
`
`the figures and text in the rest of the patent provide a description and/or examples
`
`and help explain the scope of the claims, but that the claims define the breadth of
`
`the patent’s coverage.
`
`16.
`
`I have also been informed that an “independent claim” expressly sets
`
`forth all of the elements that must be met in order for something to be covered by
`
`6
`
`

`

`that claim. I have also been informed that a “dependent claim” does not itself
`
`recite all of the elements of the claim but refers to another claim for some of its
`
`elements. In this way, the claim “depends” on another claim and incorporates all
`
`of the elements of the claim(s) from which it depends. I also have been informed
`
`that dependent claims add additional elements. I have been informed that, to
`
`determine all the elements of a dependent claim, it is necessary to look at the
`
`recitations of the dependent claim and any other claim(s) on which it depends.
`
`B.
`
`17.
`
`Person of Ordinary Skill in the Art
`
`I understand that the person of ordinary skill in the art is a
`
`hypothetical person who is presumed to have known the relevant art at the time of
`
`the invention. Factors that may be considered in determining the level of ordinary
`
`skill in the art may include: (A) the type of problems encountered in the art; (B)
`
`prior art solutions to those problems; (C) rapidity with which innovations are
`
`made; (D) sophistication of the technology; and (E) educational level of active
`
`workers in the field. In a given case, every factor may not be present, and one or
`
`more factors may predominate.
`
`18.
`
`I understand that a person of ordinary skill in the art is also a person
`
`of ordinary creativity, not an automaton. I further understand that the hypothetical
`
`person having ordinary skill in the art to which the claimed subject matter pertains
`
`7
`
`

`

`would, of necessity, have the capability of understanding the scientific and
`
`engineering principles applicable to the pertinent art.
`
`C. Claim Construction
`
`19.
`
`I understand that, in an inter partes review, claim terms are given their
`
`broadest reasonable interpretation consistent with the specification, and that, under
`
`the broadest reasonable interpretation standard, the words of a claim are generally
`
`given their ordinary and customary meaning as would be understood by a person of
`
`ordinary skill in the art in question at the time of the invention in the context of the
`
`entire disclosure.
`
`20.
`
`I also understand that, in determining the meaning of a disputed claim
`
`limitation, the intrinsic evidence of record is considered by examining the claim
`
`language itself, the written description, and the prosecution history. I further
`
`understand that a patentee may act as its own lexicographer and depart from the
`
`ordinary and customary meaning by defining a term with reasonable clarity,
`
`deliberateness and precision, but that there is a presumption that a claim term
`
`carries its ordinary and customary meaning.
`
`D. Prior Art
`
`21.
`
`I have been informed that the law provides categories of information
`
`(known as “prior art”) that may be used to anticipate or render obvious patent
`
`claims. I have been informed that, to be prior art with respect to a particular
`
`8
`
`

`

`patent, a reference must have been made, known, used, published, or patented, or
`
`be the subject of a patent application by another, before the priority date of the
`
`patent.
`
`22. Further, I have been informed that statements by a patent applicant or
`
`patentee, including statements in the patent that something is in the “prior art,” can
`
`constitute prior art that can be used to anticipate or render obvious patent claims.
`
`That is, prior art can be created by admissions of the patent applicant or patentee.
`
`23.
`
`I also understand that a person of ordinary skill in the art is presumed
`
`to have knowledge of all prior art.
`
`24. For purposes of this opinion, I have been asked to presume that the
`
`systems and components described as “conventional” and “prior art” in the
`
`Background and figures of the ’106 patent, Katayama, and the other references
`
`identified in Section III (Materials Considered) items 1-10 are prior art from a
`
`technical perspective – that is, all were available to a person of ordinary skill in the
`
`art on or before the priority date of the patent.
`
`E.
`
`25.
`
`Patentability
`
`I have been informed that a determination of whether the claims of a
`
`patent are rendered obvious by prior art is a two-step analysis: (1) determining the
`
`meaning and scope of the claims, and (2) comparing the properly construed claims
`
`to the prior art. I have endeavored to undertake this process herein.
`
`9
`
`

`

`26.
`
`I have been informed and understand that, even if every element of a
`
`claim is not found explicitly or implicitly in a single prior art reference, the claim
`
`may still be unpatentable if the differences between the claimed elements and the
`
`prior art are such that the subject matter as a whole would have been obvious at the
`
`time the invention was made to a person of ordinary skill in the art.
`
`27.
`
`I have been informed and understand that a patent claim is obvious
`
`when it is only a combination of old and known elements, with no change in their
`
`respective functions, and that these familiar elements are combined according to
`
`known methods to obtain predictable results. I have been informed and understand
`
`that the following four factors are considered when determining whether a patent
`
`claim is obvious: (1) the scope and content of the prior art; (2) the differences
`
`between the prior art and the claim; (3) the level of ordinary skill in the art; and (4)
`
`additional considerations of objective evidence, sometimes referred to as
`
`“secondary considerations,” tending to prove obviousness or non-obviousness.
`
`The additional considerations include: unexpected, surprising, or unusual results;
`
`nonanalogous art; teachings away from the invention; substantially superior
`
`results; synergistic results; long-standing need; commercial success; copying by
`
`others; and nearly-simultaneous invention by others. I have also been informed
`
`and understand that there must be a connection between these additional factors
`
`and the scope of the claim language.
`
`10
`
`

`

`28.
`
`In determining obviousness based on a combination of prior art
`
`references, I also understand that evidence of some reason to combine the
`
`teachings is required to make the combination, and thus such evidence must be
`
`considered, along with any evidence that one or more of the references would have
`
`taught away from the claimed invention at the time of the invention.
`
`29.
`
`I have also been informed and understand that some examples of
`
`rationales that may support a conclusion of obviousness include:
`
`(A) combining prior art elements according to known methods to
`
`yield predictable results;
`
`(B) simply substituting one known element for another to obtain
`
`predictable results;
`
`(C) using known techniques to improve similar devices (methods, or
`
`products) in the same way;
`
`(D) applying a known technique to a known device (method, or
`
`product) ready for improvement to yield predictable results;
`
`(E) choosing from a finite number of identified, predictable solutions,
`
`with a reasonable expectation of success—in other words, whether
`
`something is “obvious to try;”
`
`(F) using work in one field of endeavor to prompt variations of that
`
`work for use in either the same field or a different one based on design
`
`11
`
`

`

`incentives or other market forces if the variations are predictable to
`
`one of ordinary skill in the art; and
`
`(G) arriving at a claimed invention as a result of some teaching,
`
`suggestion, or motivation in the prior art that would have led one of
`
`ordinary skill to modify the prior art reference or to combine prior art
`
`reference teachings.
`
`I have also been informed that other rationales to support a conclusion of
`
`obviousness may be relied upon, for instance, that common sense (where
`
`substantiated) may be a reason to combine or modify prior art to achieve the
`
`claimed invention.
`
`30.
`
`I am also informed that a basis to combine teachings need not be
`
`stated expressly in any prior art reference. However, I understand that there must
`
`be some evidence showing an articulated reasoning with rational underpinnings to
`
`support a motivation to combine teachings and to support the legal conclusion of
`
`obviousness.
`
`31.
`
`In addition, I am informed and understand that in order to establish
`
`that an element of a claim is “inherent” in the disclosure of a prior art reference, it
`
`must be clear to one skilled in the art that the missing element is the inevitable
`
`outcome of the process and/or thing that is explicitly described in the prior art, and
`
`that it would be recognized as necessarily present by a person of ordinary skill in
`
`12
`
`

`

`the art. I understand that to establish inherency, it is not enough that a certain
`
`result or characteristic may occur or be present in the prior art, nor may inherency
`
`be established by probabilities or possibilities.
`
`VII. A Person of Ordinary Skill in the Relevant Art
`
`32.
`
`I understand that my assessment and determination of the patentability
`
`of the challenged claims of the ’106 patent must be undertaken from the
`
`perspective of what would have been known or understood by someone of ordinary
`
`skill in the relevant field as of the earliest possible priority date of the ’106 patent –
`
`March 28, 1997.
`
`A. Relevant Field
`
`33.
`
`In my opinion, the field relevant to the claims of the ’106 patent is
`
`optical data storage and retrieval, including optical pickup systems and
`
`components.
`
`B.
`
`Person of Ordinary Skill in the Art
`
`34. Based on my experience in the field, analysis of the ’106 patent, and
`
`review of the relied upon prior art references, it is my opinion that a person of
`
`ordinary skill in the relevant field as of March 28, 1997, would have had
`
`familiarity with optical data storage and retrieval devices, including optical pickup
`
`systems and components for use with CDs and DVDs, and at least a Bachelor of
`
`Science degree in electrical engineering and/or physics and 3-5 years of experience
`
`working in the field of optical data storage and retrieval, or a comparable amount
`
`13
`
`

`

`of combined education and equivalent experience with respect to optical pickup
`
`systems and devices. Strength in one of these areas can compensate for a
`
`weakness in another. Unless otherwise specified, when I state that something
`
`would be known to or understood by one skilled in the art or possessing ordinary
`
`skill in the art, I am referring to someone with this level of knowledge and
`
`understanding.
`
`35. With over 35 years of experience working in the optical data storage
`
`and retrieval field, I am well acquainted with the level of ordinary skill that would
`
`have been required to design, develop, and/or implement the subject matter of the
`
`’106 patent. I have direct experience with the relevant subject matter and am
`
`capable of rendering an informed opinion regarding what the level of ordinary skill
`
`in the art was for the relevant field as of March 28, 1997. I am also capable of
`
`rendering an informed opinion regarding what one of ordinary skill in the art
`
`would have understood as of March 28, 1997.
`
`VIII. Background of the Relevant Technology
`
`36. Optical recording media, such as CDs and DVDs, are used for the
`
`recording and/or reproduction of information. Generally, information is recorded
`
`onto an optical recording medium by changing a physical property such as the
`
`reflectivity of the optical recording medium using either a stamping process (so-
`
`called read-only media) or by means of a laser light source (in the case of
`
`14
`
`

`

`recordable and/or rewritable media). This information can be subsequently
`
`retrieved by detecting the changes in the aforementioned physical property (e.g.,
`
`optical reflectivity) using a laser light source.
`
`37. The sub-system used to read and record information on an optical
`
`recording medium is often referred to as an optical transducer or “pickup.” An
`
`optical pickup will typically have one or more light sources, an objective lens for
`
`focusing the light onto the optical recording medium, and optical detectors for
`
`reading signals reflected from the surface of the optical recording medium. Optical
`
`pickups may also include beam splitters, wave modification elements (e.g.,
`
`polarizing plates), and actuators as necessary for a particular setup and/or medium.
`
`38. Different optical recording media have different physical dimensions
`
`and specifications, including thickness and information density. For example, the
`
`specifications for CD and DVD are set forth below:
`
`15
`
`
`
`

`

`Ex. 1003, Table 1 (“Specifications of DVD and CD”). An optical recording
`
`medium having a higher density (e.g., DVD) will typically require a smaller “spot
`
`size” for reading and/or recoding information onto the disk.
`
`39. The “spot size” generally refers to the diameter of the circular patch of
`
`light formed within the focal plane of the objective lens. For a so-called
`
`diffraction-limited (i.e., aberration-free) objective lens, the spot size is directly
`
`proportional to the wavelength of the laser used, and is also inversely proportional
`
`to the numerical aperture of the objective lens. The numerical aperture may be
`
`understood as a measure of the apex angle of the cone of light formed upon
`
`passage of the laser beam through the objective lens. The spot is formed at the
`
`apex of the light cone, which ideally coincides with the focal plane of the lens,
`
`which should be the location of the information layer of a CD or DVD during the
`
`normal operation of a disc drive.
`
`40. The relationship between spot size, the numerical aperture (NA) of an
`
`objective lens, and wavelength of the light source is given by the following
`
`formula:
`
`spot size = k·wavelength/NA,
`
`where “k” is a proportionality constant of the order of unity, NA = n·sin, where n
`
`is the refractive index of the medium, and  is the half-angle subtended by the
`
`16
`
`

`

`objective lens at the apex of the light cone. See, e.g., Ex. 1009, p. 333 (1976)
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`(showing relationship for case in which k=0.5 and =i).
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`41.
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`In the early 1990’s, with the rise of DVDs and recordable and re-
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`writeable CDs, such as CD-R and CD-RW, there was a growing need for optical
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`pickups that could be compatible with multiple types of optical recording media.
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`However, designing optical pickups compatible with multiple types of optical
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`recording media (i.e., optical discs) could lead to certain problems.
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`42. For example, one could incorporate two or more independent optical
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`pickups, each complete with its own laser, beamsplitter(s), objective lens, and
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`photodetectors, into a single pickup. This, however, would have been a costly
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`proposition. Alternatively, one could use different lasers and different detectors
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`for reading/writing of different types of media (e.g., DVD, CD-R), allowing these
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`components to interact with the optical discs via a common set of beamsplitters
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`and/or polarization-sensitive optics, as well as a single objective lens. While this
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`option would have reduced the cost, weight, and complexity of the optical pickup,
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`it would have required a more sophisticated design for the common optical
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`elements, in general, and for the shared objective lens, in particular. Specifically,
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`the objective lens would now have to focus light beams emerging from different
`
`lasers, each having a specific wavelength, onto discs having different substrate
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`thicknesses.
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`17
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`43.
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`In handling different laser-light wavelengths, an objective lens has to
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`cope with “chromatic aberrations,” and in focusing these laser beams through
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`substrates of differing thicknesses, the objective lens also has to be designed to
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`correct for any resulting “spherical aberrations.”
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`44. As an example, consider the case of an optical pickup designed to
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`handle both DVD and CD-R discs. The laser wavelength appropriate to the DVD
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`is 650nm (red), while that used in conjunction with CD-R is 780nm (near infrared).
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`Unless the objective lens is designed to focus both these wavelengths and produce
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`the smallest possible “spot size” corresponding to each wavelength, it will be said
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`to suffer from chromatic aberration. At the same time, the 650nm laser beam must
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`pass through the 0.6mm thickness of the plastic substrate of a DVD before
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`reaching the information layer of the disc, whereas the 780nm laser beam must
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`pass through the 1.2mm thickness of the plastic substrate of a CD-R before
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`reaching its information layer. Unless the objective lens is properly designed to
`
`render the minimum spot-size upon focusing each laser beam through its
`
`corresponding disc substrate, it will be said to suffer from spherical aberration.
`
`45. Another complicating design factor is the required numerical aperture
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`(NA) for each type of disc: While the appropriate cone of the 780nm light formed
`
`by an objective lens for operation with CD, CD-R, and CD-RW discs must have an
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`NA equal to (or nearly equal to) 0.45, the appropriate NA for the cone of 650nm
`
`18
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`laser light directed at a DVD is expected to be in the range of 0.6 to 0.65. To
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`summarize, a dual-focus objective lens meant for use in conjunction with both CDs
`
`and DVDs must focus, without suffering from chromatic and spherical aberrations,
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`the beam from a 650nm laser into a 0.6-0.65 NA cone of light passing through the
`
`0.6mm-thick DVD substrate, and also focus the 780nm light beam into a 0.45NA
`
`cone that passes through the 1.2mm-thick CD substrate.
`
`46. The inclusion of a dual focus diffractive optical element and/or a
`
`variable aperture was common to address the above-identified issues that arise in
`
`an optical system compatible with disks of different thicknesses.
`
`47.
`
`In many cases, the objective lens was designed for spot-size
`
`corresponding to a DVD. As such, it received the 650nm laser beam and formed a
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`0.6-0.65NA cone of light passing through a 0.6mm-thick plastic substrate -- free
`
`from all forms of aberration. For operation with CDs, one of ordinary skill would
`
`have known that it was necessary to reduce the numerical aperture of the light cone
`
`formed upon passage of the 780nm laser beam through the objective lens.
`
`48. For instance, one could have used a thin-film stack (also known as
`
`interference filter) designed to pass the 650nm laser beam uninterrupted, while
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`blocking the passage of the 780nm beam in the periphery of the objective lens.
`
`This is the prior art solution described in the Background of the ’106 patent. By
`
`thus reducing the diameter of the 780nm beam (before its arrival at the objective
`
`19
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`

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`lens), the thin-film stack reduced the NA of the 780nm light cone to the desired
`
`0.45 (for CD operations).
`
`49. The reduction of numerical aperture for the 780 nm light also reduces
`
`spherical aberration. See discussion, infra at ¶¶ 54-56.
`
`50. Alternatively, it was known that a diffractive optical element co