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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 08/02/2026 has been entered.
Response to Amendment
The amendments to the claims, in the submission dated 08/02/2026, are acknowledged and accepted. Claims 1 and 4 are amended. Claims 3 and 5 are cancelled by the applicant. Claims 1-2, 4, and 6-20 are pending.
Response to Arguments
Applicant's arguments filed 08/02/2026 have been fully considered but they are not persuasive.
Applicant has argued that an absorbent present at 0.01 wt% is essential to increase the transmittance of the instant invention, and that Branda’s switching material requires absorbents to function at a much higher concentration. Examiner respectfully agrees with these facts, and further notes that because both the optical filter disclosed by Branda and the instant invention rely on absorbents to function as intended, only the amount of absorbents in each device are different, it would be within the skill of one having ordinary skill to adjust the amount of absorbent, as Branda teaches the examples presented therein are for illustrative purposes only, and are not intended to limit the scope of the invention (Branda, par. [0208]). Furthermore, Branda teaches additives, such as UV light stabilizers, for the switching material (Branda par. [0101]), and Hayes teaches the incorporation of 0.001 wt% UV absorbers into the polymers (Hayes par. [0036]).
Applicant respectfully rebuts the Examiner’s ΔT1 calculation for Branda, and further argues that Branda cannot satisfy the requirement that the layer provides an increase (ΔT1 is 0.5% or more) over the substrate-only baseline. Equation 1 defines TS1 as the transmittance of the optical filter not including the control layer, and Examiner has cited the grey glass light transmission disclosed by Branda in Fig. 9 as the transmittance of the optical filter without the control layer. That is to say, as best understood by the Examiner, the grey glass is the substrate of the optical filter disclosed by Branda, and Fig. 9 of Branda discloses the transmission percentage of the grey glass substrate. In Fig. 1 Branda shows light transmission profiles of one embodiment of the optical filter, in dark and faded states (solid and dashed lines, respectively, par. [0028]), and from Fig. 1 the average transmittance of the optical filter of example 1 of Branda in a faded state, between 481 nm and 560 nm, is about 80%. Therefore, the average transmittance in a wavelength range of 481 nm to 560 nm of the optical filter of Branda is TF1 = 0.80, and the transmittance without the variable transmittance layer, i.e., the grey glass substrate of Branda, is TS1 = 0.44, therefore ΔT1 is 81% for at least example 1 of Branda, satisfying the limitation that ΔT1 is 0.5% or more.
Applicant has argued the combination of Hayes and Branda is improper. Applicant notes that Hayes teaches UV absorbers in concentrations of 0.05 to 1.0 weight percent, (par. [0036]), and argues that a person of ordinary skill would not be motivated to reduce the absorbent concentration in Branda to the claimed 0.01wt% or less based on Hayes because doing so would render Branda's switching material inoperable for its intended light-blocking purpose. Thus, Applicant concludes that the prior art "teaches away" from the invention, as the essential function of the prior art layers requires the presence of the very absorbents the present invention seeks to minimize. Examiner respectfully disagrees.
Hayes teaches the polymer compositions may incorporate various additives known in the art, such as ultraviolet absorbers (Hayes, par. [0032]). The transitional term “comprising”, which is synonymous with “including,” “containing,” or “characterized by,” is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. See, e.g., Mars Inc. v. H.J. Heinz Co., 377 F.3d 1369, 1376, 71 USPQ2d 1837, 1843 (Fed. Cir. 2004) (“[L]ike the term ‘comprising,’ the terms ‘containing’ and ‘mixture’ are open-ended.”). Invitrogen Corp. v. Biocrest Manufacturing, L.P., 327 F.3d 1364, 1368, 66 USPQ2d 1631, 1634 (Fed. Cir. 2003) (“The transition ‘comprising’ in a method claim indicates that the claim is open-ended and allows for additional steps.”); Genentech, Inc. v. Chiron Corp., 112 F.3d 495, 501, 42 USPQ2d 1608, 1613 (Fed. Cir. 1997) (“Comprising” is a term of art used in claim language which means that the named elements are essential, but other elements may be added and still form a construct within the scope of the claim.) In this case, the composition of the glass disclosed in Branda does not preclude the inclusion of absorbents as taught by Hayes, and the prior art combination teaches an optical element with the same structure and capabilities.
With respect to Applicant’s note that Examiner has applied eight prior art references to reject the claims, Examiner agrees that a rejection is not limited to the number of references to combine to reject the claims under 35 USC 103 as obvious, and that it is uncommon to combine eight references in practice, Examiner respectfully disagrees that the number of references cited implies that the claimed invention is non-obvious. Some references are cited specifically to provide values of refractive index for material taught by other references. The primary reference Branda teaches most of the structure and limitations claimed, and the secondary references support the motivations for combination and calculations of transmittances recited in the claims.
Other arguments related to previously cited references are not addressed, since the new secondary references teach the limitations of the amended claims.
No other arguments were presented after page 4 of Remarks. As such, the prior art teaches the invention as currently claimed.
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.
Claims 1-2, 6-8, 10-12, 14-18, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Branda et al. US PGPub 2015/0109651 A1 (of record, see Office action dated 01/16/2026, “Branda”) as evidenced by Faick, Conrad A., and Alfred N. Finn. "THE INDEX OF REFRACTION OF SOME SODA‐LIME‐SILICA GLASSES AS A FUNCTION OF THE COMPOSITION 1." Journal of the American Ceramic Society 14.7 (1931): 518-528 (“Faick”), in view of Lim et al. US PGPub 2022/0320471 A1 (“Lim”), and Hayes et al. US PGPub 2007/0172637 A1 (of record, see Office action dated 05/04/2026, “Hayes”).
Regarding amended independent claim 1, Branda discloses an optical filter (title, abstract) comprising:
a substrate, wherein the substrate is a transparent glass substrate having an average transmittance of 80% or more in a wavelength range of 481 nm to 560 nm (Fig. 3, optical filter embodiment 10 has layer 12 that may be glass, par. [0075], and Fig. 1, average transmittance of the optical filter of example 1 in a faded state, between 481 nm and 560 nm, is 80%); and
a transmittance control layer formed on one or both surfaces of the substrate (an optical filter comprising a variable transmittance layer is disclosed, par. [0047], and Fig. 3 shows variable transmittance layer 14 is formed on at least one side of layer 12, par. [0075]), wherein the transmittance control layer comprises polymers, has a thickness in a range of 1 nm to 150 nm (Branda teaches the use of polymers for switching material, par. [0018], and that a suitable thickness for the switching material is about 0.1 microns, par. [0091], which is 100 nm) and wherein an absolute value of a difference in a refractive index of the transmittance control layer with respect to a refractive index of the substrate is in a range of 2% to 10% (layer 12 may be glass, and lists other exemplary materials for layer 12, par. [0084]) and DT1 is 0.5% or more in Equation 1:
[Equation 1] DT1 = 100 × (TF1 - TS1)/TS1,
wherein TF1 is an average transmittance in a wavelength range of 481 nm to 560 nm of the optical filter, and TS1 is an average transmittance in the wavelength range of 481 nm to 560 nm of the optical filter not including the transmittance control layer (glass layer 12 may be clear or grey with a visible light transmission LTA of 25% to 35%, par. [0086] and Fig. 9, light transmission spectrum for grey glass where the average transmittance over the claimed wavelength range of 481 to 560 nm is about 44%, and Fig. 1 shows light transmission profiles of one embodiment of the optical filter, in dark and faded states, par. [0028], and the average transmittance of the optical filter of example 1 in a faded state between 481 nm and 560 nm is about 80%, therefore, the average transmittance in a wavelength range of 481 nm to 560 nm is TF1 = 0.80 and the transmittance without the variable transmittance layer is TS1 = 0.44, therefore ΔT1 is 81% for at least example 1).
Branda does not disclose wherein the transmittance control layer comprises polysilazane, (Branda teaches the use of polymers for switching material, par. [0018], but not specifically polysilazane polymers), nor that the layer contains 0.01 wt% or less of an absorbent (Branda discloses that a switching material may comprise, by weight percent, 0.1 to about 30 parts of an electrochromic and/or photochromic compound, par. [0096], but does not teach 0.01 w% of an absorbent in the variable transmittance layer) and Branda does not disclose values for the refractive index of the exemplary materials for the substrate or the variable transmittance layer of the optical filter.
In a related field of invention, Lim discloses antireflection layer with a layer of polysilazane of 90 nm to 100 nm thickness, having an index of refraction of 1.39 (par. [0137]).
Therefore, it would have been obvious to a person having ordinary skill in the art, before the effective filing date of the claimed invention, to have applied the teachings of Lim to the disclosure of Branda and selected polysilazane as the material for variable transmittance layer 14, because Lim teaches polysilazane is a suitable material for optical elements with antireflection layers (Lim, par. [0137]).
The combination of Branda in view of Lim teaches and renders obvious the limitation that the polysilazane layer has a thickness in a range of 1 nm to 150 nm, because Branda teaches that a suitable thickness for the switching material is about 0.1 microns (par. [0091]), which is 100 nm, which Lim also teaches.
In the general field of optics, Faick provides measurements of the indices of refraction for glasses with values ranging from 1.49 to 1.54 (Table 1). Therefore, Faick provides a value for the refractive index of glass that Branda discloses as a suitable material for the substrate of the disclosed optical filter.
As such, the prior art combination of Branda, as evidenced by Faick, in view of Lim teaches an optical filter with an index of refraction of 1.5 for the glass substrate, and an index of refraction of 1.39 for the variable transmittance layer of polysilazane, and as such the percent difference between the indices of refraction is |1.5 – 1.39|/1.39 × 100 or 7.9%, within the claimed range of 2% to 10%.
The prior art combination of Branda, as evidenced by Faick, in view of Lim does not disclose wherein the transmittance control layer contains 0.01 wt% or less of an absorbent.
In a related field of invention, Hayes discloses polymer sheets and a laminate comprising at least one layer comprising a polymer sheet (pars. [0013-14] thereof). Hayes teaches the polymer composition may contain an ultraviolet absorber (par. [0036] thereof), where any ultraviolet absorber known in the art would find utility within the polymer sheet, and that the polymer composition preferably incorporates from about 0.001 to about 10.0 weight percent UV absorbers, more preferably 0.001 to 5.0 weight percent, and still more preferably, 0.05 to 1.0 weight percent based on the total weight of the composition (par. [0036] thereof).
Therefore, it would have been obvious to a person having ordinary skill in the art, before the effective filing date of the claimed invention, to have applied the teachings of Hayes to the disclosure of Branda and included 0.001 weight percent of any ultraviolet absorber known within the art, because Branda teaches additives, such as UV light stabilizers, for the switching material (Branda par. [0101]), and Hayes teaches the incorporation of 0.001 wt% UV absorbers into the polymers (Hayes par. [0036]), therefore the prior art combination teaches the polymer composition may incorporate various additives known in the art, such as ultraviolet absorbers (Hayes, par. [0032]) in an amount by weight percent within the claimed range.
With regard to the limitation wherein the transmittance control layer is configured to suppress reflection of light at an interface between the substrate and the transmittance control layer to increases visible light transmittance of the optical filter, the structures claimed have been mapped to the structures, elements, and features disclosed by Branda and, in combination with the other prior art references cited, teaches a device with the same structures and capable of performing the same functions and reducing the reflection of light at an interface.
Regarding dependent claim 2, the prior art combination of Branda, Faick, Lim, and Hayes (hereinafter, “modified Branda”) discloses the optical filter of claim 1, and Branda further discloses wherein TF1 in Equation 1 is 80% or more (Branda Fig. 1, average transmittance of the optical filter of example 1 in a faded state, between 481 nm and 560 nm, is 80%).
Regarding dependent claim 6, modified Branda discloses the optical filter of claim 1, and Branda as evidenced by Faick teaches wherein the refractive index of the substrate is greater than the refractive index of the transmittance control layer and the refractive index of the substrate is in the range of about 1.48 to 1.6 (Faick, Table 1, glass refractive index ranges from 1.49 to 1.54), and Lim teaches polysilazane has a refractive index of 1.39 (par. [0137] thereof).
Regarding amended dependent claim 7, modified Branda discloses the optical filter of claim 1, but the prior art combination does not further disclose wherein the transmittance control layer is formed on both sides of the substrate (Branda, in Figs. 3-6 and 7a-7h, shows sectional views of the various embodiments of the optical filter disclosed, refer to pars. [0075-78], but the variable transmittance layer 14 is not on both sides of substrate 12).
The prior art combination of Branda and Lim discloses the claimed invention except for the disposition of the variable transmittance layer on both sides of a substrate.
However, it would have been obvious to a person having ordinary skill in the art, before the effective filing date of the claimed invention, to apply a variable transmittance layer to both sides of the substrate, since it has been held that mere duplication of the essential working parts of a device involves only routine skill in the art. St. Regis Paper Co. v. Bemis Co., 193 USPQ 8 (1977). In this case, the prior art teaches a variable transmittance layer on at least one side of the substrate (refer to Branda Fig. 1), and a person of ordinary skill would have a reasonable expectation of success in applying a variable transmittance layer to both sides of substrate because the methodology would be the same for applying a variable transmittance layer to one side of the substrate.
Regarding dependent claim 8, modified Branda discloses the optical filter of claim 1, and Branda further disclose the optical filter further comprising a light absorption layer (Branda teaches the transmission of light in the ultraviolet or infrared may be blocked by absorption by one or more layers in the optical filter, pars. [0108-112]).
Regarding dependent claim 10, modified Branda discloses the optical filter of claim 8, and Branda discloses the optical filter further comprising a pressure-sensitive adhesive layer, an adhesive layer, or a primer layer between the light absorption layer and the substrate (Branda discloses an adhesive layer includes a pressure-sensitive adhesive, par. [0075]).
Regarding dependent claim 11, modified Branda discloses the optical filter of claim 10, but the prior art combination does not disclose wherein the transmittance control layer is located on a surface opposite to the surface of the substrate on which the pressure-sensitive adhesive layer, the adhesive layer, or the primer layer is formed (Branda in Fig. 4 illustrates the variable transmittance layer 14 is on the opposite side of adhesive layer 24 from substrate 12, rather than on the opposite side of substrate 12).
However, it has been held that a mere rearrangement of element without modification of the operation of the device involves only routine skill in the art. In re Japiske, 86 USPQ 70 (CCPA 1950). The rearrangement in this case does not modify the operation of the device because the optical filter of the prior art combination will still function if the variable transmittance layer is on the opposite side of the substrate from an adhesive layer, and the benefits of this modification include improved manufacturability (Branda, par. [0094]).
Regarding dependent claim 12, modified Branda discloses the optical filter of claim 10, but the prior art combination does not disclose wherein the transmittance control layer is located on a surface opposite to the surface of the light absorption layer on which the pressure-sensitive adhesive layer, the adhesive layer, or the primer layer is formed (Branda in Fig. 4 illustrates an exemplary cross-section of the optical filter, but does not disclose the disposition of the variable transmittance layer with respect to a light absorption layer such as the UV-blocking layer of PET).
However, it has been held that a mere rearrangement of elements without modification of the operation of the device involves only routine skill in the art. In re Japiske, 86 USPQ 70 (CCPA 1950). The rearrangement in this case does not modify the operation of the device because the optical filter of the prior art combination will still function if the variable transmittance layer is on a surface opposite to the surface of the light absorption layer on which the pressure-sensitive adhesive layer is formed, and the benefits of this modification include improved manufacturability (Branda, par. [0094]).
Regarding dependent claim 14, modified Branda discloses the optical filter of claim 10, and the prior art further discloses wherein a difference in the refractive index of the transmittance control layer (Lim teaches polysilazane has a refractive index of 1.39, par. [0137]) with respect to the refractive index of the substrate (Branda as evidenced by Faick has a glass substrate with n = 1.5) is in a range of about -2% to -10% (e.g., (1.39 – 1.5)/1.5 × 100 or -7.3%, within the claimed range).
Regarding dependent claim 15, modified Branda discloses the optical filter of claim 10, but the prior art combination does not explicitly disclose wherein the light absorption layer (i.e., UV-blocking layer of PET as taught by Branda in par. [0112]) is in direct contact with the pressure-sensitive adhesive layer, the adhesive layer, or the primer layer each other, nor does the prior art combination explicitly disclose the substrate (i.e., polyolefin substrate of Branda) is in direct contact with the pressure-sensitive adhesive layer, the adhesive layer, or the primer layer each other, and the prior art combination does not explicitly disclose the transmittance control layer (i.e., the variable transmittance layer of Branda) is in direct contact with the light absorption layer or the substrate.
However, it has been held that a mere rearrangement of element without modification of the operation of the device involves only routine skill in the art. In re Japiske, 86 USPQ 70 (CCPA 1950). The rearrangement in this case does not modify the operation of the device because the optical filter of the prior art combination will still function if the light absorption layer is in direct contact with an adhesive layer, and the benefits of this modification include improved manufacturability (Branda, par. [0094]).
Regarding amended dependent claim 16, modified Branda discloses the optical filter of claim 8, and Branda further discloses wherein the light absorption layer comprises a first and a second light absorption layers (Branda discloses one or more layers may comprise a UV blocking component, par. [0125]) but the prior art combination does not explicitly disclose the optical filter having light absorption layers having different refractive indices each other (Branda is silent as to the specific refractive indices of the one or more UV blocking components of the optical filter, though Branda does disclose PET as an example of a material suitable for UV blocking layers, par. [0125]), and the prior art combination does not explicitly disclose wherein the transmittance control layer (i.e., variable transmittance layer) is formed on a surface opposite to the surface of the substrate (Branda substrate 12) on which the first light absorption layer is formed (Branda in Fig. 4 illustrates an exemplary arrangement of layers in the optical filter, where variable transmittance layer 14 is on the opposite side of adhesive layer 24 from substrate 12, rather than on the opposite side of substrate 12).
However, it has been held that a mere rearrangement of element without modification of the operation of the device involves only routine skill in the art. In re Japiske, 86 USPQ 70 (CCPA 1950). The rearrangement in this case does not modify the operation of the device because the optical filter of the prior art combination will still function if the variable transmittance layer is on the opposite side of the substrate from an adhesive layer, and the benefits of this modification include improved manufacturability (Branda, par. [0094]).
With regard to the limitation of the optical filter having light absorption layers having different refractive indices from each other, Branda does disclose the UV blocking layer may be polyvinyl butyral (PVB) in par. [0112], therefore a person of ordinary skill would find it obvious to use PVB and PET as materials for two different light absorption layers in the optical filter, and the PVB and PET materials have different refractive indices, satisfying the instant limitation.
Regarding dependent claim 17, modified Branda discloses the optical filter of claim of 16, but the prior art combination does not explicitly disclose wherein the transmittance control layer is formed on a surface of the second light absorption layer opposite to the surface on which the first light absorption layer is formed (Branda in Fig. 4 illustrates the disposition of the various layers of the optical filter disclosed, but does not specify the arrangement of light absorption layers).
However, it has been held that a mere rearrangement of element without modification of the operation of the device involves only routine skill in the art. In re Japiske, 86 USPQ 70 (CCPA 1950). The rearrangement in this case does not modify the operation of the device because the optical filter of the prior art combination will still function if the variable transmittance layer is on the opposite side of the substrate from an adhesive layer, and the benefits of this modification include improved manufacturability (Branda, par. [0094]).
Regarding amended dependent claim 18, modified Branda discloses the optical filter of claim 16, and Branda further discloses wherein the first light absorption layer has a lower refractive index than the second light absorption layer (Branda discloses the one or more UV blocking layers may be PET or polyvinyl butyral, par. [0112], and the PVB and PET materials have different refractive indices being different materials, therefore the material with the lower refractive index can be selected as the first light absorption layer and the material with the higher refractive index can be selected as the second light absorption layer).
Branda does not disclose the first light absorption layer is located between the second light absorption layer and the substrate. However, it has been held that a mere rearrangement of element without modification of the operation of the device involves only routine skill in the art. In re Japiske, 86 USPQ 70 (CCPA 1950). The rearrangement in this case does not modify the operation of the device because the optical filter of the prior art combination will still function if the first light absorption layer is located between the second light absorption layer and the substrate, and the benefits of this modification include improved manufacturability (Branda, par. [0094]).
Regarding dependent claim 20, modified Branda discloses the optical filter of claim 16, and Lim further discloses wherein a difference in the refractive index of the transmittance control layer (Lim, polysilazane has index of refraction n = 1.39, par. [0137]) with respect to the refractive index of the substrate (Branda as evidenced by Faick has a glass substrate with refractive index n = 1.5) is in a range of about -2% to -10% (i.e., (1.39 – 1.5)/1.5 × 100 or -7.3%, within the claimed range of about -2% to -10%).
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Branda as evidenced by Faick in view of Lim and Hayes as applied to claims 1 and 3 above, and further in view of Suetsugu et al. US PGPub 2010/0067101 A1 (of record, see Office action dated 01/16/2026, “Suetsugu”).
Regarding dependent claim 4, modified Branda discloses the optical filter of claim 1, and Branda discloses wherein the glass substrate contains copper (Branda discloses the optical filter may have conductive material such as copper, par. [0134]), but the prior art combination does not disclose the copper is in an amount of about 10% by weight or less.
In a related field of invention, Suetsugu discloses an optical element with borosilicate glass comprising copper halide comprising from 0.01 weight percent up to 10 weight percent of the glass (par. [0026] thereof).
It would have been obvious to a person having ordinary skill in the art, before the effective filing date of the claimed invention, to have applied the teachings of Suetsugu to the disclosure of Branda and used a glass containing up to 10% by weight of copper halide for the ultraviolet ray-absorbing properties provided by the copper compounds (Suetsugu, par. [0021]).
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Branda as evidenced by Faick in view of Lim and Hayes as applied to claims 1 and 8 above, and as further evidenced by Pohlen US PGPub 2022/0171116 A1 (of record, see Office action dated 01/16/2026, hereinafter, “Pohlen”).
Regarding dependent claim 9, modified Branda discloses the optical filter of claim 8, and Faick discloses wherein an absolute value of a difference in a refractive index of the light absorption layer with respect to the refractive index of the substrate is in a range of about 0.2% to 10% (the prior art combination of Branda, as evidenced by Fiack, teaches an optical filter with an index of refraction of 1.5 for the glass substrate, and Branda teaches the use of ultraviolet-blocking polyethylene terephthalate (PET) as a light absorption layer, par. [0112], but Branda does not provide a value for the refractive index of a UV-blocking PET layer).
In a related field of invention, Pohlen discloses a laminated glazing with a core polymer layer 116 of polyethylene terephthalate (PET) having a refractive index of 1.57 to 1.58 (refer to par. [0050] thereof). Therefore Pohlen provides a value for the refractive index of PET that Branda discloses as a suitable material for a light absorption layer in the disclosed optical filter, and the absolute value of a difference in a refractive index of the light absorption layer, i.e., PET with n = 1.57, with respect to the refractive index of the substrate, i.e., glass with n = 1.5, is |1.57 – 1.5|/1.5 × 100 or 4.7%, within the claimed range of about 0.2% to 10%.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Branda as evidenced by Faick in view of Lim and Hayes as applied to claims 1, 8, and 10 above, and further in view of Lu et al. US PGPub 2021/0388149 A1 (of record, see Office action dated 01/16/2026, hereinafter, “Lu”).
Regarding dependent claim 13, modified Branda discloses the optical filter of claim 10, and Faick discloses the refractive index of the substrate (Branda discloses a glass substrate and Faick teaches glass with index of refraction of 1.5, Table 1 thereof), and Lim discloses the refractive index of the transmittance control layer (Lim teaches polysilazane with index of refraction of 1.39, par. [0137]), but the prior art combination does not disclose values for the refractive index of a pressure-adhesive adhesive layer, adhesive layer, or a primer layer.
In a related field of invention, Lu discloses polyester polyols to be used in pressure-sensitive adhesives (refer to at least abstract and pars. [0041-42] thereof). Lu teaches a pressure-sensitive adhesive with a refractive index between 1.4 and 1.7 (par. [0098] thereof).
It would have been obvious to a person having ordinary skill in the art, before the effective filing date of the claimed invention, to have applied the teachings of Lu to the disclosure of Branda and employed pressure-sensitive adhesives taught by Lu to secure layers in the optical filter, because the pressure sensitive adhesive of Lu is suitable for optical applications, being optically clear (Lu, par. [0098]).
With regard to the limitation wherein a difference in a refractive index of the pressure-adhesive adhesive layer, the adhesive layer, or the primer layer (Lu teaches a pressure-sensitive adhesive with a refractive index between 1.4 and 1.7, par. [0098] thereof) with respect to the refractive index of the substrate (i.e., glass substrate of Branda has n = 1.5 as evidenced by Faick) is in a range of about 3% to 10% (i.e., (1.6 – 1.5)/1.5 × 100 or 6.7%, within the claimed range); and a difference in the refractive index of the pressure-sensitive adhesive layer (Lu, pressure-sensitive adhesive with a refractive index between 1.4 and 1.7, par. [0098] thereof), the adhesive layer, or the primer layer with respect to the refractive index of the transmittance control layer (Lim polysilazane has a refractive index of 1.39, par. [0137] thereof) is within a range of about 8% to 15% (i.e., (1.6 – 1.39)/1.39 × 100 or 15%).
With regard to the limitation wherein a difference in the refractive index of the light absorption layer (Branda discloses a UV-blocking layer of PET, par. [0112], having a refractive index of 1.57 to 1.58 as taught by Pohlen, refer to par. [0050] thereof) with respect to the refractive index of the substrate (Branda, polyolefin substrate with index of refraction of 1.46 to 1.52 as taught by Schael, refer to at least page 2720 thereof) is in a range of about 0.2% to 2% ((1.57 – 1.52)/1.52 × 100 or 3.3%, outside of the claimed range by at least 50%).
However, Branda also teaches PET as a suitable substrate material for the optical filter (refer to par. [0125]), which has an index of refraction between 1.57 and 1.58 as taught by Pohlen (par. [0050] thereof), and as such, a person of ordinary skill using PET as a substrate and also as a light absorption layer according to the disclosure of Branda, would result in an optical filter with a difference in the refractive index of the light absorption layer with respect to the refractive index of the substrate of (1.58 – 1.57)/1.57 × 100 or 0.64%, within the claimed range of about 0.2% to 2%.
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Branda as evidenced by Faick in view of Lim and Hayes as applied to claims 1, 8, and 16 above, and as further evidenced by Pohlen, in view of Teotia, Meenu, and R. K. Soni. "Polymer interlayers for glass lamination-a review." Int. J. Sci. Res.(IJSR) 3 (2014): 1264-1270 (of record, see Office action dated 01/16/2026, hereinafter, “Teotia”).
Regarding amended dependent claim 19, modified Branda discloses the optical filter of claim 16, but the prior art combination is silent as to values of the refractive indices so as to compare the prior art to the limitation wherein a difference in the refractive index of the first light absorption layer with respect to the refractive index of the substrate is in a range of about -2% to -10% and a difference in the refractive index of the second light absorption layer with respect to the refractive index of the substrate is in a range of about 2% to 10%.
In a related field of invention, Teotia teaches polyvinyl butyral has a refractive index of 1.485 (refer to Table 2 thereof), therefore Teotia teaches a value for the refractive index of PVB that Branda discloses as a suitable material for a light absorption layer in the optical filter (refer to par. [0112] of Branda).
Pohlen teaches polyethylene terephthalate (PET), also a suitable material for a light absorption layer as taught by Branda in par. [0112], has a refractive index of 1.57 to 1.58 (refer to par. [0050] thereof).
Therefore, a difference in the refractive index of the first light absorption layer with respect to the refractive index of the substrate (i.e., polyolefin substrate 12, as taught by Branda) is in a range of about -2% to -10% (i.e., (1.485 – 1.52)/1.52 × 100 or -2.3%, within the claimed range of about -2% to -10%).
With regard to the limitation of a difference in the refractive index of the second light absorption layer with respect to the refractive index of the substrate is in a range of about 2% to 10%, PET has a refractive index of 1.57 and polyolefin has a refractive index of 1.52, so (1.57 – 1.52)/1.52 × 100 or 3.3%, within the claimed range of about 2% to 10%.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Justin W Hustoft whose telephone number is (571)272-4519. The examiner can normally be reached Monday - Friday 9:00 AM - 5:00 PM Eastern Time.
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/JUSTIN W. HUSTOFT/Examiner, Art Unit 2872
/MARIN PICHLER/Primary Examiner, Art Unit 2872
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