2006 AMENDMENT No. 1 To the Patent License for Displays and Display Illumination DatedOctober 16, 2001 (the Agreement) Background

Exhibit 10.18.1

March 17, 2006

CONFIDENTIAL TREATMENT REQUESTED. CONFIDENTIAL PORTIONS OF THIS DOCUMENT HAVE BEEN REDACTED AND HAVE BEEN SEPARATELY FILED WITH THE COMMISSION.

2006 AMENDMENT No. 1

To the Patent License for Displays and Display Illumination

Dated October 16, 2001 (the “Agreement”)

Background

Cambridge Display Technology, Limited, and Cambridge Display Technology, Inc. are either the licensing entity, controlling entity of such licensing entity, or the affiliate and Subsidiary thereof, and as such are the owner, joint owner, or sub-licensor of the Patents subject to the above referenced Agreement (collectively referred to herein as “CDT” or “Licensor”) and

E.I. du Pont de Nemours and Company (hereinafter referred to as “Licensee” of the above referenced Agreement) and Uniax Corp., now known as DuPont Displays, Inc., (a wholly owned Subsidiary of Licensee, collectively with Licensee referred to hereinafter as “DuPont”), executed the Agreement on October 16, 2001;

In the time that has passed since executing the Agreement, CDT and DuPont have continued to develop the technology relating to LEP Devices and Finished Products;

CDT and DuPont have determined that certain aspects of the Agreement do not meet the current commercial conditions relating to continued development of technology relating to LEP Devices and Finished Products; and

Consequently, CDT and DuPont have determined that amendments to the Agreement would address certain of their respective concerns, and in exchange for the mutual promises and consideration as recited herein, CDT and DuPont hereby mutually agree to amend the Agreement as set forth below and in the attached Exhibits hereto.

Amendments To The Agreement

It is agreed as follows:

This 2006 Amendment No. 1 shall be effective on date of the last signature of the parties signing this 2006 Amendment No. 1, (the “Effective Date of the 2006 Amendment No. 1”). All capitalized terms shall have the meaning set forth in the Agreement unless otherwise amended below.

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Unless otherwise defined below, the definitions of the Agreement are incorporated by reference.

Under “Have-Made Partner”, add the following words at the end of the existing definition:

—provided that such entity shall not be authorized to act as a distributor and in particular shall not be authorized to market, supply, sell or offer to supply or sell such Covered LEP Devices or Covered Finished Products otherwise than directly to the Licensee (or CDT, depending upon the context) and/or Member(s) of the Licensee’s Group (or CDT’s Group, depending upon the context).—

Under “LEP Device” add the following words at the end of the existing definition:

—and shall include back lights for use in such electronic display devices.—

Under “Licensee’s Group” add new Clause (c) as follows:

— (c) an entity to which Licensee directly or indirectly owns at least 50% of the voting securities on the date Licensee executes a sublicense to such entity and provided that the Licensee exercises effective working control over such entity; and a single entity to be nominated in writing by Licensee which Licensee directly or indirectly owns at least 40% of the voting securities on the date Licensee executes a sublicense to such entity. —

Under “More Favourable License” add the following phrase at the end of definition prior to the last period (“.”)

— , as set forth in Clauses 2.10-2.12, as amended. —

Under “Relevant Rate” Clauses a) and b) shall be replaced with the following language for Covered Cell and Covered Active Matrix Module:

— a) Covered Cell “***”

If at any time DuPont reasonably considers that the manufacturing costs (in accordance with US GAAP) of a Covered Cell are greater than “***” of the total manufacturing cost of the Covered Active Matrix Module, it shall notify CDT in writing providing such information as CDT may reasonably require to verify such manufacturing costs. In the absence of agreement, the actual manufacturing costs shall be determined by an expert who in the absence of agreement shall be appointed by the President of the Institute of Chartered Accountants, who shall sign an appropriate confidentiality agreement with DuPont. Where the expert

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determines that the manufacturing costs are within “***” of the figure provided by Dupont, the costs of the expert shall be paid for by CDT. Where the expert determines that the manufacturing costs are not within “***” of the figure provided by Dupont, the costs of the expert shall be paid for by DuPont. Upon the agreement of the parties or the determination of the expert that the manufacturing costs of a Covered Cell are greater than “***” of the total manufacturing cost of the Covered Active Matrix Module the royalty for a Covered Cell shall be reduced to:

{Manufacturing costs of a Covered Active Matrix Module divided by Manufacturing costs of a Covered Cell} multiplied by “***”

Provided always that the royalty shall never be less than “***”, unless reduced pursuant to Licensee’s More Favourable License rights.

b) A Covered Active Matrix Module — “***”—

Under “Relevant Technology” Under Clause (1)) delete the last “; and” located at the end of the paragraph and insert a period (“.”) . Then, delete all of Clause (2)(b) .

Amend Schedule 2 to add additional patents, U.S. Patent Nos. 5,895,717 and 5,682,043.

Add New Definitions as follows:

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Amend Clause 2.1(b), line 2, change the word “two” to – four –.

Delete current Clause 2.10 – insert new Clauses 2.10-2.12 as set forth below:

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to CDT and which is not unreasonably burdensome to External Counsel, which shall, amongst other matters, require the External Counsel to confine his communications to Licensee (DuPont) concerning the contents of the Third Party-agreement solely to a statement as to whether or not the Third Party-agreement under review is a Relevant Licence and if so, whether the Third Party-agreement is a Comparable Licence and/or a Cross Licence, and in each case whether the Third Party-agreement contains a More Favorable Royalty and/or a More Favorable Minimum Royalty without giving reasons. If External Counsel determines that the Third Party-agreement is a Relevant Licence, Cross Licence, or Comparable Licence, External Counsel may communicate the terms and conditions which Licencee (DuPont) will be asked by CDT to assume (namely, the Most Favourable Running Royalty, Most Favourable Minimum Royalty, and/or any Assumed Terms and Conditions) as well as External Counsel’s opinion as to what any Assumed Terms and Conditions should be.

Any and all analyses of External Counsel pursuant to this Clause 2.12(d) and any and all communications between External Counsel and Licensee (DuPont) shall be considered the attorney work product of Licensee’s (DuPont’s) attorney and/or otherwise protected from disclosure to either CDT, the arbitrator, or any other Third Party in view of Licensee’s (DuPont’s) attorney-client privilege.

Nothing in this Clause 2.12(d) or this 2006 Amendment to the Agreement, shall limit or be construed to limit Licensee’s (DuPont’s) ability to communicate information to the External Counsel or answer questions posed to Licensee (DuPont) by External Counsel so as to aid External Counsel in reaching its statement as to whether or not any Third Party-agreement under review is a Relevant Licence, Comparable Licence, and/or Cross Licence, and in each case, whether the Third Party-agreement contains a More Favorable Royalty and/or a More Favorable Minimum Royalty and the Assumed Terms and Conditions;

CDT shall remit such payment to Licensee (DuPont) within thirty (30) days of receipt of an invoice from DuPont. If payment is not received by Licensee (DuPont) within thirty (30) days, Licensee (DuPont), in addition to any other remedies, may offset the amount of any un-paid Clause 2.12(e) invoices against any other fees or payments due to CDT by either Licensee (DuPont) or any of its Subsidiaries. CDT may not audit such invoices beyond information relating to the hourly rate of the External Counsel and the total time spent on such Clause 2.12(d) review. Nothing in Clause 2.12 shall be deemed a waiver of Licensee’s (DuPont’s) attorney-client privilege as to any communication with External Counsel or other counsel and nothing shall be construed to permit CDT, arbitrator, or any other Third Party to have access to any of attorney work product of External Counsel (including all Clause 2.12(d) statements made to Licensee (DuPont) or other Licensee (DuPont) counsel);

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                    end of new Clause 2.12                    

Renumber original Agreement Clauses 2.12 to 2.15, to become renumbered Clauses 2.13 to 2.16, respectively.

Under Clause 4.1, first paragraph, line 2, and insert after “Relevant Technology” the following phrase:

— , subject to the requirements of Clause 4.1(c) below, —

Add new Clause 4.1 (c) as follows:

— (c) As a condition of the license granted under Clause 4, CDT, its Subsidiaries, and Members of CDT’s Group, hereby agree to be bound the terms and conditions attached here to as Exhibit A. With respect to CDT’s rights under the Relevant Technology listed in Schedule 2 of the Agreement all terms and conditions of the Agreement, the 2006 Amendment No. 1, and its Exhibit A shall govern CDT’s rights thereto.

To the extent any term or condition of the Agreement or the 2006 Amendment No. 1 renders any term and condition of Exhibit A impossible to perform, the terms and conditions of Exhibit A shall govern, control, or otherwise determine CDT’s rights, privileges, obligations, and performance related to CDT’s and Members of CDT’s Group’s exercise of the Clause 4 license granted under the DuPont / Uniax Reference 001 listed in Schedule 2 of the Agreement, and CDT and Members of CDT’s Group shall comply with the requirements and obligations as set forth in Exhibit A. –

5. Notwithstanding any paragraph to the contrary in the Agreement, (i) *** as required by DDI’s agreements *** and as required by the *** (including, but not limited to, to the *** and its accountant ability to inspect this Agreement, records relating thereto, etc.) or Licensee’s Group who are similarly bound to treat this as confidential, or (ii) either Party may disclose, without the other Party’s consent, the Agreement and amendments thereto to any Third Party advisors, investors, acquirers or prospective investors or acquirers who are similarly bound to treat the Agreement (and amendments thereto) as confidential under similar terms and conditions as provided by the Agreement.

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6. CDT reserves the right to terminate its sublicense to the Regents Patents without terminating its licensed rights to the other patent and patent applications listed in Relevant Technology.

7. CDT hereby waives its entitlement to the accumulative sum of “***” in respect of any payments due during the duration of the Agreement as may become due on or after January 1, 2006 under Clauses 3.1 - 3.14 of the Agreement, including, but not limited to, the running royalties due on Covered LEP Devices and the Minimum Royalty calculated on October 16, 2006, (as may be due by any activities of DuPont, its Have Made Partners, DuPont Subsidiaries, or Members of Licensee’s Group); PROVIDED that such waiver shall cease to apply to any unused portion of the “***” as of the effective date of any assignment pursuant to Clause 12.2 of the Agreement.

8. DuPont hereby provides *** pursuant to original Clause *** of the Agreement (renumbered in view of this 2006 Amendment No. 1 as Clause ***), in relation to the arrangements that CDT has entered into with Sumitomo Chemical Company Limited for the formation of Sumation Company Limited as described in CDT’s filings with the U.S. Securities and Exchange Commission in November 2005. DuPont explicitly ***.

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OTHER TERMS AND CONDITIONS OF THE 2006 AMENDMENT

Unless otherwise explicitly stated in this 2006 Amendment No. 1, terms and conditions of the 2006 Amendment No. 1 shall be applicable to prospective activities of the Parties taken after the Effective Date of the 2006 Amendment No. 1.

IN WITNESS WHEREOF, the CDT and DuPont have executed this 2006 Amendment No. 1 to the Agreement, in duplicate originals, and by their respective duly authorized officers, as signed below.

For:

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