A TRIZ-based Evaluation Process for Patents and Patent Portfolio

The value of a patent or a patent portfolio is mainly determined by their technological and commercial strength, of course also by its claim scope. The patent evaluation process then becomes very essential for the analysis of competitive advantage of the players in the market. A process for evaluating one patent or a patent portfolio includes normally the claim construction, analysis of embodiment and technical background, which are completed by referring to their prior arts. The latter are usually analyzed on the base of citation index, which implies the ideas source of the present patent(s). Comparing with the cited prior arts, this study adopts another list of prior arts, which are developed by aid of the TRIZ methodology. The functional analysis, ideality, trimming technique and conflicts analysis are used for generating a set of feasible concepts. These concepts are then used to determine the non-obviousness of the concerned patents, whose value could then be made together with other information. The study confirms the usage of TRIZ methodology for the evaluation of patents, the applied process is also validated for the evaluation of organizational intellectual properties, which are formerly lack of a consistent evaluation process. I. Patent Evaluation as a competitive tool The evaluation of patented technology and its portfolio is essential in the corporate activity. By evaluating the patent portfolios of competitors, a valuable technical and legal information could be obtained and be useful in the following litigation or licensing issues. On the other hand, when an enterprise’s intellectual proprietary is taken as asset, its revealed value could be a solid evidence that facilitates the technology transfer, venturing or merging between companies. An evaluation is usually focused on a set of related patents, so-called patent portfolio, which is qualified by its number of patents, correlation of technologies, probability of prior arts, quality of patents and their use in the industry, most importantly, the legal status determines the enforceability of the patent rights. The evaluation criteria are then designed to check the patentability, defensibility, claim construction, infringement support and the offensive viewpoint. The patentability concerns mainly the novelty and non-obviousness of a patent, while the defensibility confirms its claimed scope in view of possible prior arts. The claim construction and infringement support determine the quality of a patent and its enforceability in case of infringement. The offensive examines if a patent is easy to be designed around or just ignored. Being practiced for long terms, these criteria serve well for providing legal basis to evaluate the intellectual proprietary of a company (inventors), but the evaluation on technical basis is still absent. This drawback may be complemented by using TRIZ methodology as technology decoder and a set of new criteria. II. Procedure of Evaluation To propose a feasible evaluation process, this study adopts the criteria of patentability, defensibility and offensive to examine the value of a patent portfolio. A modified patent analysis based on TRIZ methodology such as conflicts analysis, functional analysis, Su-Field analysis, trimming are employed for seamless connection between patent description and its corresponding technical system. Fig.1 Process of evaluation based on TRIZ approach. According to Figure.1, a process is then implemented here for this evaluation study, the main function and system conflicts should be firstly identified according to the key patents in a portfolio. Secondly, a problem statement should be made, which explains how the problems are solved by current patents. Thirdly, the ways other patents solved the problems should be researched by thoroughly searching the patent databases (by citation and queries formulated from main function and system conflicts). Fourthly, the possible ways could be proposed by TRIZ methodology should be developed and checked in the patent databases. And finally, an evaluation based on typical patent criteria and ideality will be carried out. A patent portfolio of a textile company, PLT (for reason of respect, a pseudo name is used, and their patent numbers are not indicated), is selected as the corpus of analysis, whose technical domain is electric heating fabric articles and their manufacture. The demonstration follows. A. Identification of key patents: Key patents are defined here as patents which determine the general structure of a technical system, and play an important role in the prosecution process of the portfolio in question. In general, the search of key patents could be done from two kinds of analysis, the patent citation analysis and the patent family analysis. The patent citation analysis is based on the disclosed cited and citing documents in a patent, the cited documents are taken as technology background to be improved by the patent, the citing documents are improvements based on current patent if any. By the logic of citation, the analysis about the patens’ citation history will disclose a technology roadmap which explains how a technical system will develop across a timeline usually more than twenty years. And this information provides a competitive knowledge about the companies and inventors. The key patents, from the viewpoint of a citation analysis, are the most cited and dominant patents in the technological main streams. In this study, a set of patented technologies are identified, such as windproof and water resistant composite fabric with barrier layer, method of forming electric heating fabric articles. The citation tree implies that the electric heating technology of PLT is based on protective fabrics technology which facilitates a wearable electric heating clothing article. If a citation tree reveals the major influences of precedent technologies, a patent family analysis tells otherwise the intention a company had for obtaining a strong patent portfolio. When a patent application is filed, the continual development of a related technology could be applied in form of continuation applications or continuation in part applications, and these applications form (relevant legally and technologically) a set of patent family. By this logic, deployment of the application timeline will produce a patent family analysis, as shown in Figure.2. Fig.2, Patent family analysis of PLT’s electric heating technology Y ea r of A pp lic at io n Year of Publication In this figure, four types of technological systems have been identified, including 1) General electric heating/warming fabric article, which comprises a fabric pre-body, an electric heating/warming element, an electric conducting element, a barrier and a fabric body. These patents describe some combinations of the methods and articles of the general structure. 2) Electric heating yarns, which are woven, knitted, embroidered or laid in the electric heating/warming fabric article. 3) The electric heating/warming film, mainly the coated/printed layout on the fabric pre-body. 4) Special designs, including blader or phase change materials which improve the use condition of electric heating/warming fabric article An analysis based on patent family could then be taken as an effective tool to identify important and exact trends about how a product technology has been deployed by a company from the beginning. The PLT develops its thermal technology based on group (1) and deploys its variances in form of yarns, film and special applications. It should pay attention that a patent receives three patented technology and influences nine new developments, which could be taken as a key patent in the portfolio scope. Fig.3 the raised surface and the embedded electric heating elements By the above observation and a close examination of the key patents, a good understanding about the thermal technology is established, which could be depicted as follows: 1) The cores of the thermal technology in PLT’s products are its early developed fleece/raised fabric structure and the waterproof/windproof technologies, which serve as insulation of heating yarns and barrier to water respectively. 2) The yarns, layout and formation of the electric heating/warming fabric article characterize secondly the whole design. 3) From the two protected concepts, some innovations could be further developed. B. System Conflicts: In an electric heating fabric article, the electric heating elements are used for heating human body. They are usually in forms of wires or yarns, connected by electrodes and form parallel/series layouts and performing a larger planar surface heating. These kinds of layout have various disadvantages including, non-uniformity of heating, rigid touch, easy short-circuiting due to liquid wetting, not washable, not flexible...etc. Thousands of patents have been issued for solving these problems and, among which, the ones that concern uses on human body at extreme cold weather and at active sports are the focus of this study. Fig.4 Conflicts diagram for major components Accordingly, the main function is heating the human body, which is non-uniformly heating and uncomfortable contact, and the short-circuiting could be caused by the sweat or rain, are demonstrated in the conflict graph in Figure.4. C. How PLT Solved the conflicts? According to the former patent documents study, the electric heating/warming fabric article by PLT is characterized by the way of implementation of electric heating elements(wire/yarns) in the pre-body(fleece/raised), and barrier layer implement. Fig.5 The functional analysis of PLT electric heating fabric article For implementation of the process, this technical system is visualized by way of functional analysis, as shown in Figure.5. The electric heating fabric article contains an electric heating elements which heat (generally non-uniformly), and the pre-body is served to hold (by knitting/weaving) the electric heating elements, and uniformly distribute the heat, as what other products do. But most importantly, by its raised surface (fleece construction), the electric heating elements are embedded and isolated from the environment or human body. It could be obvious that, without direct contact with the heated object, the over-heating will not occur, and the modified fabric surface will offer more comfortable hands. By this design, another outer shell for encapsulation is no more necessary, which makes this configuration more effective. It should be noticed that, the human body sweats a lot while exercising actively, even in cold and snow climate. The sweat will cause the electric heating elements short-circuited, while in current inventions, a water-proof and wind-proof membrane is attached on the inner surface to block the influence of sweat. When the membrane is formed on the outer surface of the pre-body, it's destined for repelling the rain droplets. These characteristics assure the patentability of PLT technologies, but it’s worth examining what others have done on these technical issues (knitting, isolating, barriers). D. Alternative Solutions The functional analysis of PLT’s patents of electric heating fabric characterizes that the electric heating element, fabric pre-body and the barrier layer define the major interests of the patent portfolio which solved two main conflicts about non-uniform heating and water caused short-circuit. In order to proceed to the evaluation of the portfolio, the study executes a patent citation search in the USPTO patent database, and formulates other queries that describe the two main conflicts. A number of patents have been collected and selected by the limitation that they’ve solved the same conflicts as PLT’s patents did. D.1 How others solved the conflicts? The selected patents are listed in Table.1 in terms of publication date and their major components description. It’s clear from the comparison that, the system conflicts are solved in very different ways. Firstly, for avoiding the rigid touch with the human body and direct contact between conductive yarns, the electric heating elements are insulated by wounded non-conductive yarns or by interlacing (knitting/weaving) with textile yarns which cover the elements. Secondly, the woven/knitted fabric pre-body are used for embedding the electric heating elements, it has two improvements including waterproofing, channeled spaces for housing the heating elements. Finally, it’s noticeable that, the waterproof function is usually imparted on the fabric pre-body, but the solution of PLT attaches a waterproof/windproof membrane which facilitates a flexible installation. Table.1 The prior arts and relevant patents of the PLT thermal technology Patent Number Title Publication Date Electric heating element Fabric Prebody Barrier Fabric body US1015991 ELECTRIC HEATING PAD 1912/1/30 resistance conductor flexible waterproof insulating material RE22512 ELECTRIC HEATING SYSTEM FOR GARMENTS AND OTHER OBJECTS 1940/5/16 resistance conductor two waterproofed layers or sheaths, with channel US3425020 WOVEN HEATER 1969/1/28 zig-zag interlaced, wrapped to insulate woven fabric N/A US3478422 METHOD OF MAKING AN ELECTRIC BLANKET 1969/11/18 insulated yarns, weft inserted warp double knitting fabric, forming 2 layers N/A US4459461 Flocked electric blanket construction 1984/7/10 electric heating wire foamed and flocked woven fabric with channels 2000~2005 conductive yarns/ wires that woven, knitted, embedded, laid into the prebody knitted/woven with raised surface waterproof/ windproof membrane two layers, stitched adhered or laminated US6941775 Tubular knit fabric and system 2005/9/13 spirally knitted with insulating yarns stretchable tubular knitting US7038170 Channeled warming blanket 2006/5/2 heating yarns two seamed fabric layers having channels MMI-Thermal Technology Patents D.2 How could it be solved otherwise by TRIZ approach? In addition to the prior arts searched from the patent databases, another list of conceptual prior-arts is developed and verified by using TRIZ methodologies as catalysis of inspiration. The conceptualization begins basically from the functional analysis, and then deploys the ideas by conflicts analysis, Su-Field analysis and trimming respectively. The results from trimming technique are selected for this study and could be consulted in Table.2, some improvements are demonstrated as +/signs in order to check their ideality relative to solutions of PLT. These concepts are deployed on an assumption that they provide major benefits and without introducing new harms, which means their main improvements are based on elements elimination without sacrificing the main functions. Table.2 The list of conceptual solutions inspired by TRIZ approach Elements Process Material TZ1 covered with laminated/coated film + TZ2 with water resistant sheat-core yarn structure + + A liquid-resistant fabric prebody TZ3 DWR treated, resin dipping/encapsulating or watertight weaving structure + + + TZ4 an airy and bulky waterproof electric heating element that could be kintted/woven into a fabric + TZ5 an electric heating film that could be easily attached onto a fabric layer + + Electric heating element supported by barrier TZ6 a waterproof membrane which offers comfort hands and could support the attahcment of electric heating elements + + . The waterproof electrode TZ7 the insulated electric heating elements whose connections with the electrodes are secured by waterproof treatment (eg. non-conductive coating) + + MMI Thermal Technology Patents MM raised fabric that insulates electric heating elements and onto which a waterproof membrane is attached . . . "+": improved, "-": worsen, ".": no significant change Solution A self-supporting electric heating element that Cost Trimmed concepts A liquid-resistant electric heating element