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 .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Claim Rejections - 35 USC § 103
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.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-2, 8-11, and 17-20 are rejected under 35 U.S.C. 103 as being unpatentable over Maeda et al. (US PGP 2017/0285496 A1), in view of Hirakata et al. (US PGP 2019/0094722 A1).
Maeda teaches an electrophotographic photoreceptor including a conductive support and a photosensitive layer containing an electric charge generating material and an electric charge transport material. A layer configuring the surface of the electrophotographic photoreceptor is taught to contain a resin binder, and conductive particles A and B dispersed in the resin binder (Abstract).
An image forming apparatus including image forming units (process cartridges) containing the structural components recited in instant claim 10, claim 11, claim 17, claim 18, claim 19, and claim 20 is also described ([0014]-[0032], Fig. 1).
In an embodiment, the photoreceptor is taught to include a conductive support, an interlayer, a photosensitive layer, and a surface layer. In this embodiment, the surface layer disposed on the photosensitive layer is the layer configuring the surface of the electrophotographic photoreceptor (containing the conductive particles A and B).
However, in another embodiment, the photoreceptor may not include the surface layer disposed over the photosensitive layer. In this case, the layer configuring the surface of the electrophotographic photoreceptor (containing the conductive particles A and B) is taught to be the photosensitive layer ([0072]). In other words, Maeda teaches an embodiment where the photosensitive layer contains the conductive particles A and B (which reads on the corresponding limitation recited in instant claim 1).
The conductive particles are taught to include metal oxide particles like alumina, zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, indium oxide doped with tin, tin oxide doped with antimony, and zirconium oxide ([0037]). In other words, the conductive particles are taught to include inorganic oxide particles (which reads on the corresponding limitation recited in instant claim 1).
The conductive particles A are taught to have a single peak in a range of 80 nm to 200 nm and the conductive particles B are taught to have a single peak in a range of 10 nm to 30 nm in a particle size distribution based on the number of particles ([0008], [0053]-[0054]). In other words, the conductive particles A correspond to the claimed “large-diameter particles B” and the conductive particles B correspond to the claimed “small-diameter particles A” recited in instant claim 1.
The particle diameter d1 of the conductive particles A at the peak and the particle diameter d2 of the conductive particles B at the peak are taught to satisfy the Expression (1) below ([0055]):
(4 x d2) ≤ d1 ≤ (20 x d2)
In other words, the relationship between the particle diameter d1 at the peak of the conductive particles A and the particle d2 at the peak of the conductive particles B can be rewritten as follows:
4 ≤ (d1/d2) ≤ 20
or
20 ≥ (d1/d2) ≥ 4
As discussed above, d1 is the particle diameter of the “large-diameter” conductive particles A having a single peak in a range of 80 nm to 200 nm, and d2 is the particle diameter of the “small-diameter” conductive particles B having a single peak in a range of 10 nm to 30 nm in a particle size distribution based on the number of particles. In other words, the peaks of the particle diameters of the conductive particles A and B satisfy the claimed formulas (A1) and (A2) recited in instant claim 1 and claim 2.
In the examples, the surface of the photoreceptor of Example 1 contained tin oxide particles having an average particle diameter of 100 nm as the conductive particles A and tin oxide particles having an average particle diameter of 20 nm as the conductive particles B ([0096], Table 21) (which falls within the corresponding ranges recited in instant claim 9). Therefore, the ratio of the average particle diameter of the “large-diameter” conductive particles A to the average particle diameter of the “small-diameter” conductive particles B was 5 (which reads on the corresponding formula (α1) recited in instant claim 9).
As discussed above, Maeda teaches that the photoreceptor may or may not include a surface layer disposed over the photosensitive layer, and that the photosensitive layer may contain the conductive particles A and B. However, Maeda appears to be silent to teach or suggest that the photoreceptor may include an inorganic protective layer provided on the photosensitive layer, as recited in instant claim 1 and claim 9.
Katsuhara teaches an electrophotographic photoreceptor including a conductive substrate, a photosensitive layer, and an inorganic protective layer. The inorganic protective layer is taught to contain a Group 13 element and oxygen (Abstract).
Katsuhara teaches that forming an inorganic protective layer on an organic photosensitive layer is known since an organic photosensitive layer has flexibility but tends to readily deform (which reads on the corresponding limitation recited in instant claim 1 and claim 9).
Additionally, Katsuhara teaches that inorganic protective layers are hard but have a tendency to exhibit poor toughness, resulting in dents sometimes occurring in the inorganic protective layer due to the electrophotographic carrier pressing again the inorganic protective layer at the transfer position of the image forming apparatus during the image forming process ([0022]-[0023]).
Accordingly, Katsuhara teaches that an inorganic protective layer formed of a metal oxide layer can be used from the viewpoint of mechanical strength and is preferably a metal oxide layer composed of a Group 13 element and oxygen since its mechanical strength, translucency, and electrical conductivity are excellent ([0208]).
The metal oxide including the Group 13 element and oxygen is taught to preferably be gallium oxide, since gallium oxide has excellent mechanical strength, translucency, n-type conductivity, and excellent conduction controllability ([0210]) (which reads on the corresponding limitations recited in instant claim 8).
Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have formed an inorganic protective layer over the photosensitive layer (containing the conductive particles A and B) of Maeda’s photoreceptor, in view of improving the mechanical strength of the photoreceptor.
It would have also been obvious to have used an inorganic protective layer formed of a metal oxide layer containing gallium oxide, as Katsuhara teaches that gallium oxide is known to exhibit excellent mechanical strength, translucency, n-type conductivity, and conduction controllability compared to other suitable metal oxides.
Allowable Subject Matter
Claims 3-7 and 12-16 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
U.S. Pre-Grant Publication 2014/0295334 A1 to Hirakata et al. teaches an electrophotographic photoreceptor including a conductive substrate, an organic photosensitive layer, and an inorganic protective layer. The organic photosensitive layer is taught to include a charge transport material and silica particles in a region on the surface side in contact with the inorganic protective layer (Abstract).
The volume average particle diameter of the silica particles is taught to preferably be from 20 nm to 200 nm, and the content of the silica particles is taught to be 30% by weight to 70% by weight with respect to the total weight of the charge transport layer ([0077], [0095]). Additionally, the inorganic protective layer is taught to include oxide-based inorganic materials such as gallium oxide ([0118]).
However, Hirakata does not teach or suggest forming the charge transport layer including more than one type of silica particles having different particle sizes (e.g., “small-diameter” and “large-diameter” particles), let alone satisfying the claimed relationship represented by the claimed formula (A1) or the claimed formula (α1) (see [0247] and Tables 1-7).
U.S. Pre-Grant Publication 2021/0271179 A1 to Suzuki et al. teaches an electrophotographic photoconductor including an electroconductive substrate, a charge generation layer, and a charge transport layer. The charge transport layer is taught to contain an inorganic oxide (Abstract).
In the examples, the charge transport layer of the photoconductor of Example 43 contained silica particles having a primary particle diameter of 50 nm and silica particles having a primary particle diameter of 100 nm (Table 9 and Table 12). While Suzuki teaches forming the charge transport layer including more than one type of silica particles having different particle sizes (e.g., “small-diameter” and “large-diameter” particles), the relationship between the particle diameters of the particles fails to satisfy the claimed formula (α1).
Additionally, Suzuki is silent to teach or suggest the highest peaks of the silica particles in a particle distribution of the silica particles, and, therefore, does not teach or suggest that the silica particles satisfy the claimed formula (A1). Suzuki is also silent to teach or suggest forming an inorganic protective layer of the photosensitive layer.
U.S. Pre-Grant Publication 2020/0241434 A1 to Takahashi et al. teaches an electrophotographic photosensitive member including a support, a charge-generating layer, and a charge-transporting layer. The surface layer of the photosensitive member is taught to contain inorganic particles having a particle diameter (Lα) of primary particles of 5 nm or more and 50 nm or less and resin particles having an average particle diameter (Lβ) of 0.1 µm or more and 5.0 µm or less (Abstract). When the photosensitive member does not include a protective layer, the charge-transporting layer is taught to be the surface layer ([0075]).
The inorganic particles are taught to include silica and aluminum oxide, from the viewpoints of hardness, insulating property, and light transmittance ([0022]). In the examples, the inorganic particles included silica and aluminum oxide having an average particle diameter ranging from 9 to 40 nm (Table 1).
Therefore, Takahashi does not teach or suggest forming the surface layer including inorganic particles having the satisfying the claimed definition of the “small-diameter” and “large-diameter” particles, let alone satisfying the claimed relationship represented by the claimed formula (A1) or the claimed formula (α1). Takahashi is also silent to teach or suggest forming an inorganic protective layer of the photosensitive layer.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Boone A Evans whose telephone number is (571)272-1420. The examiner can normally be reached Monday - Friday: 9:00 AM - 6:00 PM EST.
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/BOONE ALEXANDER EVANS/Examiner, Art Unit 1737
10/02/2026
1 Table 2 appears to erroneously use units of “µm” instead of “nm” to depict the average particle diameter.
Prosecution Insights