Prosecution Insights
Last updated: April 19, 2026
Application No. 18/089,826

ELECTROPHORETIC MEDIA COMPRISING ELECTROPHORETIC PARTICLES AND A COMBINATION OF CHARGE CONTROL AGENTS

Non-Final OA §103§112
Filed
Dec 28, 2022
Examiner
BHUSHAN, KUMAR R
Art Unit
1766
Tech Center
1700 — Chemical & Materials Engineering
Assignee
E Ink Corporation
OA Round
1 (Non-Final)
73%
Grant Probability
Favorable
1-2
OA Rounds
2y 10m
To Grant
99%
With Interview

Examiner Intelligence

Grants 73% — above average
73%
Career Allow Rate
576 granted / 789 resolved
+8.0% vs TC avg
Strong +34% interview lift
Without
With
+33.5%
Interview Lift
resolved cases with interview
Typical timeline
2y 10m
Avg Prosecution
45 currently pending
Career history
834
Total Applications
across all art units

Statute-Specific Performance

§101
0.7%
-39.3% vs TC avg
§103
42.9%
+2.9% vs TC avg
§102
21.8%
-18.2% vs TC avg
§112
21.1%
-18.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 789 resolved cases

Office Action

§103 §112
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. Priority This application has PRO 63/296,179 01/04/2022. Information Disclosure Statement The information disclosure statement (IDS), filed on 06/10/25, 12/12/23, 05/09/23, and 02/09/23 have been considered. Please refer to Applicant's copy of the 1449 submitted herewith. Election/Restrictions Applicant’s election without traverse of claims 1-13 and species a. Amino group and carboxylic acid group as polar groups of the second charge control agent; b. Ricinoleic acid monomer for polymeric tail of second charge control agent; c. Molecular structure of second charge control agent: A polyamine having a polyricinoleic acid functional group, and a carboxylic acid anion, and d. The polymer layer on first, second, third, and fourth types of particles is adsorbed in the reply filed on 09/29/25 is acknowledged. Claims 1-20 are pending. Claims 14-20 are directed to non-elected invention. Accordingly, claims 14-20 are withdrawn from further consideration by Examiner, 37 CFR 1.142(b), as being drawn to non-election invention. Claims 1-13 are examined in this Office action. Claim Objections 7. Claim 10 is objected to under 37 CFR 1.75 as being a substantial duplicate of claim 6. When two claims in an application are duplicates or else are so close in content that they both cover the same thing, despite a slight difference in wording, it is proper after allowing one claim to object to the other as being a substantial duplicate of the allowed claim. See MPEP § 706.03(k). Claim Rejections - 35 USC § 112 The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claims 11-12 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claim 11 recites the limitation "the first zeta potential" in line 4. There is insufficient antecedent basis for this limitation in the claim. Claim 12 recites the limitation "the electrophoretic display" in line 1. There is insufficient antecedent basis for this limitation in the claim. Appropriate correction is required. Claim Rejections - 35 USC § 103 The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. Claims 1-4, 7-9, 12-13 are rejected under 35 U.S.C. 103 as being unpatentable over Telfer (US 2020/0242993) in view of Thetford (US 6787600). Regarding claims 1-4, 12, Telfer discloses an electrophoretic medium (para [0047]) comprising non-polar solvents (para [0152]), a first type of particles comprising white pigments, wherein pigments comprising inorganic metal oxide, e.g. titanium dioxide, wherein the first type of particles having negative charge polarity (para [0100], [0160], [0264]), a second type of particles comprising cyan pigments, the second type of particles having positive charge polarity, wherein the polarity of second type of particles being the opposite of first type of particles (para [0100]), a third type of particles (read on claimed fourth particles) comprising yellow pigments, the third type of particles having negative charge polarity (para [0100]), and fourth type of particles (read on claimed third particles) comprising magenta pigments, the fourth type of particles having positive charge polarity (para [0100]) and a first charge control agent having a molecular structure, the molecular structure of the first charge control agent including at least one quaternary ammonium group and a non-polar tail such as Solsperse 19000 (para [0119], [0152], [0153]). Regarding claim 1 recitation “a second charge control agent having a molecular structure, the molecular structure of the second charge control agent including two or more polar groups, and a non-polar tail, the two or more polar groups being selected from the group consisting of amino group, sulfonate group, sulfate group, sulfinate group, carboxylic acid group, phosphonic acid group, phosphinate group, phosphate group, hydroxyl group, thiol group, alpha diketone group, beta diketone group, ethylene oxide group, and propylene oxide group, the non-polar tail comprising a polymeric group, the polymeric group being formed by a monomer comprising an alkyl or alkenyl group having at least ten carbon atoms,” applicants in specification discloses “[Para 78] The molecular structure of the second charge control agent includes two or more polar groups and a non-polar tail. The polar groups are selected from the group consisting of amino group, carboxylic acid group, phosphonic acid group, hydroxyl group, thiol group, alpha diketone group, beta diketone group, ethylene oxide group, and propylene oxide group,” “[Para 79] The non-polar tail of the second charge control agent may comprise a polymeric group having one or more saturated alkyl functional groups. The non-polar tail of the second charge control agent may comprises a polymeric group having at least one carbon-carbon double bond. The polymeric group may be formed by a monomer comprising at least ten carbon atoms,” and “[0091] A non-limiting example of a commercial polymeric material that can be used as a second charge control agent is Solsperser™ 8000 supplied by Lubrizol Corporation.” Telfer discloses Solsperser™ 8000 (para [0289], table 10). The examiner search and interpretation do no conclude Solsperser™ 8000 read on claim 1 features. As such Telfer do not disclose elected species of the second charge control agent, e.g., a polyamine having a polyricinolic acid. However, Thetford discloses an ink composition comprising liquid carrier, pigment, and dispersant (column 8, lines 36-44), wherein the dispersant is polyamine containing side chain of two or more type of polyester chain is a derivatives of one or more hydroxy carboxylic acid such as ricinoleic acid (column 1, lines 48-, column 3, lines -2), wherein the dispersant give rise to higher gloss reading and lower haze values in the inks and further exhibits reduced flocculation in inks (column 11, lines 30-34). It would have been obvious to one with ordinary skill, in the art at the time of invention, to modify Telfer with dispersant comprising polyamine containing side chain of two or more type of polyester chain is a derivatives of one or more hydroxy carboxylic acid such as ricinoleic acid, as taught by Thetford. The rationale to do so would have been motivation provided by of Thetford that to do so would give rise to higher gloss reading, lower haze values, and exhibits reduced flocculation in inks. Regarding claims 7-9, Telfer discloses all the four particles have a layer of polymer adsorbed to the respective pigment cores (see fig 2 and par [0134]). Telfer further discloses the cyan, yellow and magenta type particles comprise a polymer which may be formed by methyl methacrylate and a monomer comprising dimethylsiloxane (para [0213], [0215] and [0216]). Regarding claim 13, Telfer includes the features of claim 1 above. Telfer further discloses (para [0084]) a color electrophoretic display ("color electrophoretic display") comprising said electrophoretic medium which is comprised in an electro-optic material layer being disposed between a first light-transmissive electrode layer (para [0167]; "front electrode"; "the display viewed through the front electrode") and a second electrode layer (para [0167]; "pixel electrode of the backplane") including an array of thin film transistors coupled to pixel electrodes (para [0198] and [0206]; "thin-film transistor array backplane"). Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Telfer in view of Thetford as applied to claim 1, and further in view of Rosenthal (US 2018/0031994). Telfer includes the features of claim1 above. Regarding claim 5,Telfer does not disclose the second charge control agent includes a comb polymer having alkyl or alkenyl branches and two terminal polar functional groups. However, Rosenthal discloses an ink composition comprising liquid carrier, pigment, and dispersant (para [0009], [0019]-[0020]), wherein the dispersant comprises comb polymer containing two-component structure comprising an anchor group of polyamine and one or more polymeric chains having alkyl or alkenyl acidic side chains (para [0039]-[0050], [0066]), wherein the anchor group absorbed onto the surface of the pigment particle and the polymeric side chains give steric stabilization, so as to hold the particles apart (para [0038], [0046]). It would have been obvious to one with ordinary skill, in the art at the time of invention, to modify Telfer with dispersant comprising comb polymer containing two-component structure comprising an anchor group of polyamine and one or more polymeric chains having alkyl or alkenyl acidic side chains, as taught by Rosenthal. The rationale to do so would have been motivation provided by of Rosenthal that to do so would provide the anchor group absorbed onto the surface of the pigment particle and the polymeric side chains provide steric stabilization, so as to hold the particles apart. Claims 6, 10 are rejected under 35 U.S.C. 103 as being unpatentable over Telfer in view of Thetford as applied to claim 1, and further in view of Fazel (US 2007/0286975). Telfer includes the features of claim 1 above. Regarding claims 6, 10,Telfer does not disclose the water-soluble ether having molecular weight of from 75 to 5,000 Dalton. However, Fazel discloses electro-optic display comprises volume resistivity reducing agent comprising polyethylene glycol having a number average molecular weight not greater than about 2000 (para [0054]), overlapping claimed range of from 75 to 5,000 Dalton. Telfer (para [0314]) and Fazel (para [0054]) are pertinent to electro-optic display. It would have been obvious to one with ordinary skill, in the art at the time of invention, to modify Telfer with polyethylene glycol having a number average molecular weight not greater than about 2000, as taught by Fazel. The rationale to do so would have been motivation provided by of Fazel that to do so would decrease internal electrical resistance, making electro-optic display more conductive or less insulating. A prima facie case of obviousness exists for the electrophoretic medium, wherein Telfer teaches polyethylene glycol having a number average molecular weight not greater than about 2000, overlapping the requirement of claims 6, 10. See In re Wertheim regarding prima facie cases with overlapping ranges (In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976) See MPEP § 2144.05). Allowable Subject Matter The following is a statement of reasons for the indication of allowable subject matter: Claim 11 is currently not allowed (please See 112 rejection above. The closest prior art is Telfer. Claim 11 require the polarities of the second, third, and fourth types of particles are all positive, wherein the second type of particles has a second zeta potential, wherein the third type of particles has a third zeta potential, wherein the fourth type of particles has a fourth zeta potential, wherein the first zeta potential is larger than the second and third zeta potentials, and wherein the fourth zeta potential is smaller than the third zeta potential. Telfer discloses two positive and two negative particles (para [0100]) and the zeta potentials of all four particles (table 2). However, Telfer does not teach the second, third, and fourth types of particles are all positive; and the first zeta potential is larger than the second and third zeta potentials. The closest prior arts do not suggest or disclose the claimed electrophoretic medium. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to KUMAR R BHUSHAN whose telephone number is (313)446-4807. The examiner can normally be reached 9.00 AM to 5.50 PM (EST). Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, RANDY P GULAKOWSKI can be reached at (571)272-1302. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /KUMAR R BHUSHAN/Primary Examiner, Art Unit 1766
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Prosecution Timeline

Dec 28, 2022
Application Filed
Jan 15, 2026
Non-Final Rejection — §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
73%
Grant Probability
99%
With Interview (+33.5%)
2y 10m
Median Time to Grant
Low
PTA Risk
Based on 789 resolved cases by this examiner. Grant probability derived from career allow rate.

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