Patent Court Decision, 2016Heo7695, dated August 17, 2017
PATENT COURT OF KOREA
SECOND DIVISION
DECISION
Case No.: 2016Heo7695 Rejection (Patent)
Plaintiff: A
United States
Representative B
Defendant: Commissioner of the Korean Intellectual Property Office
Date of Closing Argument: June 28, 2017
Decision Date: August 17, 2017
ORDER
1. The IPTAB decision rendered in Case No. 2016Won2362 (announced August 16, 2016) shall be vacated.
2. The litigation costs shall be borne by the Defendant.
PLAINTIFF’S DEMAND
As ordered.
OPINION
1. Facts
A. Claimed Invention (Defendant’s Exhibit 5, final specification as amended on November 26, 2014)
(1) Title of the Invention: Higher Transmission Light Control Film
(2) Translation Filing Date / International Filing Date / Priority Date / Korean Patent Application No.: May 14, 2010 / October 13, 2008 / October 16, 2007 / No. 10-2010-7010587
(3) Claims (hereinafter Claim 1 of the Claimed Invention will be referred to as “Claim 1”)
[Claim 1]
A light control film, comprising:
a light input surface and a light output surface opposite the light input surface; alternating transmissive and absorptive regions disposed between the light input surface and the light output surface;
a first interface between a transmissive region and an adjacent absorptive region (hereinafter “Element 1”);
an interface angle θ1 an interface angle θ1 defined by the first interface and a direction perpendicular to the light output surface (hereinafter “Element 2”);
with each transmissive region having an index of refraction N1, and each absorptive region having an index of refraction N2, where N1-N2 is not less than 0.005 (hereinafter “Element 3”); and where θ1 is not greater than 3 degrees (hereinafter “Element 4”).
[Claims 2-5] (omitted)
4) Main Content and Drawings
(a) Technical Field
The Claimed Invention generally relates to light control films (LCF)1) and displays incorporating the same (see paragraph [0001]).
(b) Problem to Be Solved
The Claimed Invention is directed to an LCF having an enhanced brightness and uniformity of transmitted light while maintaining a well-defined viewing cutoff angle. A portion of the light entering the LCF undergoes Total Internal Reflection (TIR) within the LCF, increasing the amount of light transmitted through the film. In one aspect, the LCF is placed between the light source and an image plane of a backlit display, to improve the display brightness and uniformity without reducing resolution. (See paragraph [0015].)
(c) Solution to the Problem
Included wall angle θT is two times the interface angleθI … for symmetric absorptive regions (see paragraph [0025]).
In one aspect, the Claimed Invention can be directed to LCFs where the included wall angle can be not greater than 6°. …
As such, in one aspect, the interface angle can be 3°, or not greater than 3° or less, for example 2.5°, 2°, 1°, or 0.1°, or less. Smaller wall angles can form grooves having a relatively high aspect ratio (H/W) at a smaller pitch “P,” and can provide a sharper image cutoff at a lower viewing angle. (See paragraph [0027])
[Fig. 3] A perspective view of an LCF
FIG. 5 shows an LCF 500 according to one aspect of the Claimed Invention. The light transmission of the LCF is greater than the light transmission through prior art LCFs, since some of the light impinging on absorptive regions 140 is reflected by TIR. LCF includes transmissive regions 130 comprising a material having index of refraction Nl, and absorptive regions140 comprising a material having an index of refraction N2 which is not greater than Nl. The critical angle, θc (not shown) for the interface is θc= arcsin(N2/Nl). Light rays impinging on interface 150 at angles greater than θc undergo TIR at interface 150. Light rays impinging on interface 150 at angles less than θc are absorbed by absorptive regions 140 (See paragraph [0029]).
The included wall angle θT, transmissive index N1, and absorptive index N2, are adjustable parameters for control of the transmission of light through light output surface 120. Selection of these parameters can cause some of the light which would otherwise be absorbed by absorptive region 140, to instead be reflected from interface 150 and directed through the output surface within the intended internal viewing cutoff angle ΦI. (See paragraph [0030].)
[Fig. 5] A schematic sectional
view of the LCF
B. Prior Arts
(1) Prior Art 1 (Plaintiff’s Exhibit 7)
(A) Prior Art 1 relates to “a light-collimating film” published in International Publication No. WO 2007/084297 (published on July 26, 2007)
(B) Main Content and Drawings
(a) Technical Field
Prior Art 1 relates to a Light Collimating Film (title of the invention).
(b) Solution to the Problem
The transparent microstructures between grooves have an included wall angle θ as depicted in FIG. 2; a maximum transparent microstructure width, W; an effective height, D; center-to-center spacing, S; and a maximum viewing range, ΦΤ. Wall angle θ is equal to 2 times the angle formed between the transparent film interface with the light absorbing element nearly along the “D” dimension direction and a plane normal to the microstructured surface (see page 4, lines 17-22).
In preferred embodiments, the included wall angle of the microstructures averages less than 6˚ and more preferably averages less than 5˚ (e.g., less than 4˚, 3˚, 2˚, 1˚, or 0 ˚). Smaller (i.e., steeper) wall angles are amenable to producing grooves having a relatively high aspect ratio (D/W) at a smaller center-to-center spacing S5, thereby providing a sharper image viewability cutoff at lower viewing angles (see page 5, lines 4-8).
To reduce reflections at the light transmissive film/light absorbing material interface, it may be desirable to match or nearly match the index of refraction of the transmissive film material with the index of refraction of the light absorbing material over all or a portion of the visible spectrum. Accordingly, the difference in the index of refraction of the cured transparent film in comparison to the (e.g., cured) light absorbing elements typically ranges from 0 to 0.002. Reducing such reflections tends to reduce the formation of ghost images2) (see page 6, lines 9-15).
[Fig. 2] A perspective view of a light-collimating film
(2) Prior Art 2 (Plaintiff’s Exhibit 8)
(A) Prior Art 2 relates to Japanese Laid-Open Patent Publication No. 2006-171701, published on June 29, 2006, “a view angle controlling sheet and liquid crystal display apparatus using the same.”
(B) Main Content and Drawings
(a) Technical Field
Prior Art 2 relates to a view angle controlling sheet having the function of preferably controlling the light beam from a light source of a liquid crystal display apparatus (see paragraph [0001]).
(b) Problem to Be Solved
An objective of Prior Art 2 is to provide an inexpensive view angle controlling sheet to be disposed between the light source and the display panel of a liquid crystal display apparatus, effective for limiting the light beam output angle for the peeping prevention, the reflection prevention, or the like while providing a high light beam transmittance to the observer side so as to provide the excellent light utilization efficiency (see paragraph [0004]).
(c) Solution to the Problem
Claim 1 of Prior Art 2 relates to a view angle controlling sheet to be disposed between the light source and the liquid crystal panel of a crystal display apparatus, … wherein with the premise that the angle formed by the slant face portion of the wedge part and the normal of the light output plane is θ, θ is in a range of 3˚≤ θ≤15˚ (see paragraph [0006]).
According to Prior Art 2, in the case the angle θ formed by the slant face portion of the wedge part and the normal of the light output plane is less than 3˚ the diffused light beam from the light source cannot reach sufficiently to the observer front side so that the luminance improving effect cannot be obtained. On the other hand, in the case θ is more than 15˚, due to too small the area of the lens part for having the diffused light beam from the light source transmitted, the luminance is lowered. In order to maintain the front side luminance using the view angle controlling sheet of Prior Art 2, the preferable range of θ is 3˚ or more and 15˚ or less (see paragraph [0009]).
Claim 4 of Prior Art 2 is characterized in that with the premise that the refractive index of the main material comprising the wedge part is N2 and the refractive index of the material comprising the lens part is N1, the relationship of N2<N1 is satisfied. According to Prior Art 2, since the refractive index difference of the light transmissible resin as the material comprising the lens part and the main material comprising the wedge part is provided larger by N2<N1, the total reflection in the slant face portion of the wedge part can be carried out efficiently so that the luminance deterioration in the front side can be restrained (see paragraph [0012]).
[Fig. 1] A first embodiment of a view angle controlling sheet
C. Prosecution History
(1) First Final Rejection
(A) The KIPO examiner issued a Notice of Preliminary Rejection on September 26, 2014 on the grounds that the pre-amendment Claim 1,1) cannot be registered under Article 29(2) of the Korean Patent Act for lacking of inventiveness over Japanese Laid-Open Patent Publication No. 2006-343711 (December21, 2006; hereinafter the “Cited Reference”) (see Defendant’s Exhibit 2).
(B) In response, the Plaintiff submitted an argument on November 26, 2014, along with an amendment by which Claim 1 has been amended in part, as indicated above in Section 1.A.(3). In the argument, the Plaintiff stated that the Cited Reference is designed to have an interface angle of 3 degrees to 15 degrees, while the Claimed Invention is designed to have an interface angle of 3 degrees or less, and that due to this difference in construction, the Claimed Invention has inventiveness over the Cited Reference (see Plaintiff’s Exhibit 3). However, the KIPO examiner issued a Notice of Final Rejection (hereinafter, the “First Final Rejection”) on March 19, 2015 on the grounds that changing the range of the interface angle, while including all the features of the Cited Reference, is merely a design modification that those skilled in the art would have easily made by choice (see Defendant’s Exhibit 3).
(C) In response, the Plaintiff filed an administrative appeal against the First Final Rejection with the Intellectual Property Trial and Appeal Board (“IPTAB”) (Case No. 2015Won3473). On September 30, 2015, the IPTAB rendered a decision to revoke the First Final Rejection on the following grounds (see Defendant’s Exhibit 4):
“The Cited Reference discloses that an angle (θ) formed by the slant surface portion of the wedge-shaped portion and the normal of the outgoing light beam plane is in the range of 3 degrees to 15 degrees. Thus, despite having an overlapping value(s) in the boundary of the numerical range for the interface angle with that of the Claimed Invention (for instance, an interface angle of 3 degrees), the Cited Reference clearly discloses as follows:
… the luminance improvement effect cannot be obtained because the diffused light beam cannot reach an observer-side front face when θ is lower than 3 degrees. In order to maintain the front face luminance with the view angle controlling sheet, θ preferably ranges from 3 degrees to 15 degrees.
In view of the foregoing, the Cited Reference teaches to set the interface angle of 3 degrees or larger and thus, explicitly excludes the technical feature of having an interface angle not greater than 3 degrees in Claim 1. Accordingly, Claim 1 would not have been easily derived by those skilled in the art from the corresponding elements of the Cited Reference.”
(2) Second Final Rejection
(A) At the re-opened examination, the KIPO examiner issued a Notice of Preliminary Rejection on October 28, 2015 stating that Claim 1 would have been easily derived by those skilled in the art by simply combining Prior Art 1 with the element of Prior Art 2 corresponding to Element 4 of Claim 1 (see Plaintiff’s Exhibit 4).
(B) In response to the Notice of Preliminary Rejection above, the Plaintiff filed an argument on January 28, 2016 stating that since (i) neither Prior Art 1 nor Prior Art 2 discloses or suggests anything related to the interface angle θ1 not greater than 3 degrees or the refractive index difference N1-N2 not less than 0.005 as in Claim 1, and (ii) with the special numerical limitations above, Claim 1 can provide a remarkable effect in enhancing the luminance of a display, those skilled in the art would not have easily conceived Claim 1 from Prior Art 1 and Prior Art 2. Regardless, the KIPO examiner issued again a Notice of Final Rejection (hereinafter, the “Second Final Rejection”) on March 22, 2016 stating that the grounds of rejection above were not satisfactorily resolved (see Plaintiff’s Exhibit 5).
(3) The IPTAB Decision
Accordingly, the Plaintiff filed an administrative appeal against the Second Final Rejection (Case No. 2016Won2362). The IPTAB rendered a decision on August 16, 2016 dismissing the appeal on the grounds that (i) Prior Art 1 discloses substantially the same elements as Elements 1, 2, and 4 of Claim 1, and Prior Art 2 discloses substantially the same element as Element 3 of Claim 1 by stating that in the case of N2<N1, the luminance deterioration on the front side can be restrained, and that the refractive index difference is 0.08 (N1-N2=0.08); (ii) there would not have been any technical difficulty in combining Prior Art 1 and Prior Art 2, and both Prior Art 1 and Prior Art 2 do not teach away from their combination; thus, those skilled in the art would have easily combined Prior Art 1 and Prior Art 2; and (iii) accordingly, Claim 1 lacks inventiveness in view of the combination of Prior Art 1 and Prior Art 2 (see Plaintiff’s Exhibit 6).
[Factual Basis] Undisputed facts, Plaintiff’s Exhibits 1 to 8, Defendant’s Exhibits 1 to 5, and the purport of the overall argument.
2. Summary of the Parties’ Arguments
A. Plaintiff's Argument for Revocation of the IPTAB Decision
1) The Defendant's argument that the Claimed Invention lacks inventiveness over Prior Art 1 alone, or Prior Art 2 as the primary reference, constitutes a new ground of rejection to which the Plaintiff has not given any opportunity to respond during the examination or the administrative trial. If this new ground of rejection was notified, the Plaintiff would have been able to successfully resolve it by making any necessary amendments, including deleting the element of the interface angle of 3 degrees, which overlaps in part with Prior Art 2. In this regard, the Defendant should not be allowed to argue a new ground of rejection during the present revocation action of the IPTAB decision.
2) Prior Art 1 discloses that when a refractive index difference between a transmissive material and a light absorbing material is greater than 0.002, it would increase reflections at the light transmissive film/light absorbing material interface and form many ghost images, and explicitly excludes the element of the refractive index difference being equal to or greater than 0.005 as in Claim 1. Prior Art 2 also discloses the numerical range of the interface angle that is opposite to the numerical range of Element 4 in Claim 1 over the boundary of 3 degrees and excludes an interface angle of less than 3 degrees for luminance on the front side, while Claim 1 sets the interface angle to 3 degrees or less and improves display uniformity and brightness over the entire viewing angle. Claim 1 aims to provide a light control film with improved display uniformity and brightness by means of organically combining the elements related to the refractive index difference and the interface angle. Such combinations, however, are not indicated in either of Prior Art 1 and Prior Art 2 at all. Further, both Prior Art 1 and Prior Art 2 do not provide any suggestion or motivation for their combination, which even leads into the loss of the technical significance of reducing the formation of ghost images as originally provided from Prior Art 1. Thus, Claim 1 would not have been easily derived by those skilled in the art in view of the combination of Prior Art 1 and Prior Art 2. In this regard, Claim 1 is not found to lack inventiveness over each or the combination of Prior Art 1 and Prior Art 2.
B. Defendant's Argument
1) 1)Prior Art 1 presents substantially the same elements as Elements 1, 2, and 4 of Claim 1. Further, Element 3 of Claim 1 limits the refractive index N1 of a transmissive region and the refraction index N2 of an absorptive region in Element 1 of Claim 1 to having a difference in the range of 0.005 or greater (i.e., N1-N2≥0.005). However, the effect resulting from the claimed numerical limitation above is neither distinguishable nor remarkable. In addition, Prior Art 2, which is the same as Prior Art 1 in terms of technical field and objective, discloses that the lens portion (transmissive region) and the wedge-shaped portion (absorptive region) have refractive indices of 1.56 and 1.48, respectively, so that the difference therebetween is 0.08 (i.e., N1-N2=0.08), and this feature is substantially the same as Element 3 of Claim 1. Accordingly, Claim 1 would have been easily conceived by those skilled in the art in view of Prior Art 1 alone or the combination of the feature of N1-N2=0.08 in Prior Art 2 with Prior Art 1 and thus lacks inventiveness.
2)Prior Art 2 discloses substantially the same elements as Elements 1, 2, and 3 of Claim 1. Further, Element 4 of Claim 1 limits the interface angle (θ1) in Element 2 of Claim 1 to 3 degrees or less (i.e., θ1≤3°). However, the effect resulting from the claimed numerical limitation above is neither distinguishable nor remarkable. In addition, Prior Art 2 discloses that the angle formed by the slant face portion of the wedge part and the normal of the outgoing light beam plane (i.e., the interface angle θ) is set to be 3°≤θ≤15°. This numerical range, however, overlaps with that of Element 4 of Claim 1 over the boundary of 3°, and Prior Art 1, which is the same as Prior Art 2 in terms of technical field and objective, also discloses an included wall angle of less than 6° (i.e., the interface angle of less than 3°). Accordingly, Claim 1 would have been easily conceived by those skilled in the art in view of Prior Art 2 alone or the combination of the feature of the included wall angle of 6° or less (i.e., the interface angle of less than 3°) in Prior Art 1 with Prior Art 2 and thus lacks inventiveness.
3) Although the Claimed Invention was finally rejected due to lack of inventiveness only on the ground of the combination of Prior Art 1 and Prior Art 2 during the examination and the administrative trial, the Defendant's argument that Claim 1 lacks inventiveness in view of each or the combination of Prior Art 1 and Prior Art 2 is consistent in essence with the grounds for the final rejection above and thus does not constitute a new ground of rejection.
3. Whether Claim 1 Lacks Inventiveness When Prior Art 1 Is Relied upon as the Primary Reference
A. Whether the Defendant’s Argument Constitutes a New Ground of Rejection
1) Standard of Analysis
To finally reject a patent application at the examination, the KIPO examiner should preliminarily reject the application first to give the applicant a full opportunity to respond to the rejection, and in order for the IPTAB to decide that the KIPO examiner's decision of final rejection is proper on new grounds other than those of the final rejection during the administrative trial regarding the final rejection, the applicant must be given the opportunity to respond before the IPTAB cites the new grounds as the basis of its decision (see Articles 62, 63, and 170 of the Korean Patent Act). Given that the provisions under the Korean Patent Act ensuring procedural rights as the above are compulsory, the IPTAB errs in denying the appeal from the KIPO’s final rejection stating that it was justified on new grounds, to which the Plaintiff was never given an opportunity to respond. In the same vein, in the revocation action against IPTAB decision on an appeal from final rejection, the Commissioner of KIPO is not allowed to raise such a new ground absent any prior opportunity for the applicant to respond thereto at the examination or administrative trial. However, even if a ground of rejection is newly raised by the KIPO's Commissioner at the revocation proceeding, the new ground may serve as a basis for determining whether the IPTAB decision is proper, as long as the ground is consistent in essence with a previously notified ground(s) raised at the examination or administrative trial and is thus merely a supplementation of the previously notified ground(s) (see Supreme Court Decision 2013Hu1054, rendered on September 26, 2013).
2) Analysis
(A) According to the IPTAB decision, Claim 1 would have been easily conceived by those skilled in the art by combining the element of N1-N2=0.08 in Prior Art 2 with Prior Art 1 and is thus found to lack inventiveness. On the other hand, the Defendant argued in this litigation as the ground of justifying the conclusion of the IPTAB decision that Claim 1 would have been easily conceived by those skilled in the art in view of Prior Art 1 and is thus found to lack inventiveness.
(B) In view of the procedures below and the grounds of rejection found by taking into account the description in each of Plaintiff’s Exhibits 2 to 6 and Defendant’s Exhibits 1 to 5 together with the purport of the overall arguments, the Defendant's argument that Claim 1 lacks inventiveness in view of Prior Art 1 does not necessarily take away from the Plaintiff's opportunity to present any response and amendment regarding this inventiveness issue. Accordingly, the Plaintiff's assertion that the Defendant's argument above constitutes a new ground of rejection is dismissed.
1) In the Notice of Preliminary Rejection dated October 28, 2015, the KIPO examiner indicated that Claim 1 lacks inventiveness on the grounds that despite the absence of any disclosure in Prior Art 1 corresponding to Element 3 of Claim 1, a refractive index of a material is only a matter of choice that those skilled in the art would have easily made as needed, and thus, there would not have been any difficulty in constructing Element 3 of Claim 1.
2) The grounds of rejection set forth in the IPTAB decision and the Defendant's argument in this litigation equally state that Claim 1 lacks inventiveness when Prior Art 1 is relied upon as the primary reference, and that the difference between the Claimed Invention and Prior Art 1 relates to Element 3 of Claim 1 providing the difference between refractive indices of the transmissive region and the absorptive region (N1-N2) as not less than 0.005.
3) The issue of whether an invention claimed in a patent application has inventiveness is determined by taking into consideration all circumstances, including the technical level and technical common sense at the time of filing, basic problems desired to be solved in the technical field, technical problems and effects of the claimed invention and a prior art invention(s), and the issue of whether there is any suggestion or motivation for combining prior arts. In particular, whether there is any prior art that provides a suggestion or a motivation for or teaches away from a combination of prior art inventions is merely one of many factors to consider in determining inventiveness.
4) In determining inventiveness in view of Prior Art 1 and the combination of Prior Art 1 and Prior Art 2, the important factors to consider include: the circumstances such as what technical problem and effect of Element 3 of Claim 1 are, whether the technical problem or effect is disclosed in Prior Art 1 or is generally recognized in the relevant art, what technical means are provided to solve the technical problem, and whether there would have been any difficulty in adopting the technical means described in Claim 1 among those provided to solve the problem. The IPTAB too reviewed whether Claim 1 lacks inventiveness on the following grounds: (i) setting the size of difference in the refractive index is merely a matter of choice that those skilled in the art would have easily made as appropriate depending on the material used for a film(s); and (ii) the Claimed Invention is also silent on the critical significance or effect resulting from the refractive index difference of 0.005.
5)Therefore, the Plaintiff was given the full opportunity to respond by submitting an argument regarding whether those skilled in the art would have easily overcome the difference between Claim 1 and Prior Art 1, or by amending Element 3. The Plaintiff asserted that, in its argument submitted on January 28, 2016, no prior arts disclosed or implied the refractive index difference between the transmissive and the absorptive regions not less than 0.005, and that the Claimed Invention provided a remarkable effect of improving the display luminance by setting limitations on the interface angle and the refractive index difference between materials used in the transmissive region and the absorptive region.
B. Element-by-element Comparison between Claim 1 and Prior Art 1
C. Summary of Comparison
1) Claim 1 and Prior Art 1 are the same as each other in terms of: (i) Element 1, i.e., a light control film2) (a light collimating film) comprising a light input surface (a top surface of a microstructured film article), a light output surface (a surface where the microstructured film article contacts a base substrate layer), a transmissive region (transparent microstructures between grooves or transmissive film material), an absorptive region (a light absorbing material) and a first interface (an interface of a transparent film having light absorbing elements); and (ii) Elements 2 and 4, i.e., an interface angle θ1, defined as the angle between the first interface and a direction perpendicular to the light output surface, is not greater than 3 degrees (an included wall angle of less than 6 degrees, which is two times the angle defined between the transparent film interface with the light absorbing element and a plane normal to the microstructured surface).
2) With respect to Element 3, however, Claim 1 is different from Prior Art 1 in that Claim 1 specifies the difference in the index of refraction between a transmissive region and an absorptive region (i.e., N1-N2) as not less than 0.005, while Prior Art 1 discloses that the difference in refractive index between a light transmissive film material and a light absorbing material is in the range of between 0 and 0.002.
D. Whether Those Skilled in the Art Would Easily Overcome the Difference
In view of the following, as found based on the disclosure of each of the Plaintiff’s Exhibits 7 to 8, and Defendant’s Exhibit 5 together with the purport of the overall argument, the foregoing difference would not have been easily overcome by those skilled in the art.
1)The Claimed Invention relates to a light control film that increases the axial brightness of light (in front of a display user) and enhances uniformity of the brightness within viewing angle, while providing a sharp viewing cutoff angle. According to Element 3 of Claim 1, the difference in the index of refraction between an absorptive region and a transmissive region (N1-N2) is in the range of N1-N2≥0.005 in order to cause total internal reflection (TIR) at an interface between the absorptive region and the transmissive region of the light control film, thereby increasing the amount of light (luminance) passing through the film and eventually increasing the luminance of the display (see Defendant’s Exhibit 5, paragraphs [0015], [0019] and [0029]).
2) The specification of Prior Art 1 includes a portion reading as follows:
To reduce reflections at the light transmissive film/light absorbing material interface, it may be desirable to match or nearly match the refractive index of the transmissive film material with that of the light absorbing material over all or a portion of the visible spectrum. Accordingly the difference in the index of refraction of the cured transparent film in comparison to the (e.g. cured) light absorbing elements typically ranges from 0 to 0.002. Reducing such reflections tends to reduce the formation of ghost images (see Plaintiff’s Exhibit 7, p. 6, lines 9-15).
According to the description above, Prior Art 1 limits the difference in refractive index between the light transmissive film material and the light absorbing material to next to none, in the range of between 0 and 0.002, to reduce reflections at an interface between the light transmissive film material and the light absorbing material, thereby reducing the formation of ghost images. Prior Art 1 neither discloses nor implies anything relating to increasing the luminance of the light passing through a light control film using total reflections caused by a difference in refractive index.
3) Thus, Claim 1 and Prior Art 1 are different from each other in terms of the technical problem to be solved through refractive index difference, and in terms of the effect resulting from the refractive index difference.
4) Based on the fact that Prior Art 1 discloses the technical feature of adjusting the refractive index of the light transmissive film material and the light absorbing material, and Prior Art 2 discloses limiting the difference in refractive index between a lens portion (light transmissive region) and a wedge part (light absorbing region) to 0.08, the Defendant argues that those skilled in the art would have easily overcome the foregoing difference by combining Prior Arts 1 and 2. As discussed above, however, Prior Art 1 matches or nearly matches the refractive index difference of the transmissive film material with that of the light absorbing material, thereby preventing reflections at an interface, while Prior Art 2 discloses that the difference in refractive index between the material comprising the lens part and the material comprising the wedge part (N1-N2) as N1>N2, thereby causing reflections at an interface (a slant face of the wedge part) (see Plaintiff’s Exhibit 8, paragraph [0012]). Thus, upon combining the element in Prior Art 2 providing a larger refractive index difference, it will be difficult to achieve the objective of Prior Art 1 through the difference in refractive index, i.e., obtaining the effect of reducing the formation of ghost images by reducing the occurrence of reflections at the interface. Further, Prior Art 1 fails to include any other portion that suggests or motivates introduction of the refractive index difference of Prior Art 2. Thus, those skilled in the art would not have easily overcome the difference of Claim 1 by combining Prior Arts 1 and 2.
5) The Defendant argues that the method of using the total reflection of light to increase the luminance of the light control film and the method of removing the total reflection of light to remove ghost images are replaceable with each other and thus those skilled in the art would have easily chosen one method as needed without undue technical effort. The Defendant's produced evidence alone, however, is not enough to conclude that the foregoing had been technical common sense prevailing at the time of filing or had been obvious among those skilled in the art.
E. Summary of the Analysis
In view of the foregoing, those skilled in the art would not have easily derived Claim 1 in view of Prior Art 1 or in view of the combination of Prior Art 1 and Prior Art 2. Thus, Claim 1 does not lack inventiveness over the Prior Arts.
4. Whether Claim 1 Lacks Inventiveness When Prior Art 2 Is Relied upon as the Primary Reference
A. Whether the Defendant’s Argument Constitute a New Ground of Rejection
1) Standard of Analysis
The ground of rejection newly raised by the Commissioner of the KIPO in the revocation action against IPTAB decision on an appeal from final rejection may serve as a basis for determining whether the IPTAB's decision is proper only when the new ground is consistent in essence with the previously notified ground, for which an opportunity to respond was given at the examination or administrative trial, and thus is no more than a supplementation to the previously notified ground. In case a new ground of rejection raised in litigation concerns inventiveness of the claimed invention, the new ground is consistent in essence with the previous ground of rejection if:
The same prior art are cited to show that each element of the claimed invention was already made public;
Both grounds of rejection are consistent in major part with each other with respect to the factual premises necessarily reviewed in determining the inventiveness of the claimed invention over the prior art references (such as the level of skills, technical commonsense and the fundamental problem to be resolved in the art at the time of filing), the key elements focused in the determination, the issues subject to determination (such as the technical problem to be solved, technical means to solve the problem, and motivation/suggestion of combination or difficulty in combination); and the same direction of argument or amendment is expected from the Applicant in overcoming the rejection and thus the Applicant is regarded as having been given an actual opportunity to respond to the new ground of rejection.
Even if a ground newly raised in litigation cites the same prior arts used to find lack of inventiveness at the examination and administrative trial and is merely different in whether prior arts are combined or how they are combined, it constitutes an impermissible new ground of rejection inconsistent in essence with the ground previously raised at the examination and administrative trial if: the factual premises, the key elements in the determination, or the issues subject to determination is changed, and thus the applicant has never been given an opportunity to submit argument or make amendment to that ground.
2) Analysis
(A) The IPTAB decision states that Claim 1 lacks inventiveness because it would have been easily conceived by those skilled in the art by combining the element of N1-N2=0.08 in Prior Art 2 with Prior Art 1. On the other hand, the Defendant argues in this litigation as the ground of justifying the conclusion of the IPTAB decision that Claim 1 would have been easily conceived by those skilled in the art in view of Prior Art 2 or the combination of the included wall angle in a range of less than 6° in Prior Art 1 (i.e., an interface angle of less than 3°) with Prior Art 2, and is thus found to lack inventiveness.
(B) In view of the following facts and reasons found as a result of taking into account the disclosure of each of Plaintiff’s Exhibits 2 to 6 and Defendant’s Exhibits 1 to 5, together with the purport of the overall arguments, the ground of rejection the Defendant cites in the litigation is not consistent in essence with the ground of rejection for which an opportunity to respond was given at the examination and administrative trial, and thus constitutes a new ground of rejection.
1) The difference between the Claimed Invention and the Prior Arts discussed in the Notice of Second Final Rejection and the IPTAB's decision is different from that raised in the Defendant's argument in this litigation. In other words, the Notice of Second Final Rejection and the IPTAB's decision state that Claim 1 is different from the invention previously made public (Prior Art 1) in terms of refractive index difference in Element 3, but here the difference between Claim 1 and the invention previously made public (Prior Art 2) lies in the interface angle of Element 4 according to the Defendant’s argument.
2) As a result of the difference above, the ground of rejection in the Notice of Second Final Rejection and the IPTAB decision is also different from the Defendant's argument in terms of the factual premises necessarily considered in determining inventiveness and the reasoning to the conclusion. In others words, when comparing the Claimed Invention with Prior Art 1 to determine inventiveness as in the Notice of Second Final Rejection and the IPTAB decision, inventiveness is determined based on what technical problem and effect is achieved by Element 3 from the aspect of the refractive index difference, whether the technical problem or effect is disclosed in Prior Art 1 or had been commonly recognized in the art, what types of technical means for solving the problem exist, whether Prior Art 1 suggests or motivates a combination of the corresponding elements of Prior Art 2 to Prior Art 1, among others. On the other hand, when comparing the Claimed Invention with Prior Art 2 to determine inventiveness, as in the Defendant's argument, the same questions as above will be discussed based on Element 4, i.e., the interface angle range.
3) Although it is not specified which of Prior Art 1 and Prior Art 2 is the primary reference at the examination or administrative trial proceedings, the Claimed Invention was found to lack inventiveness over the combination of Prior Art 1 and Prior Art 2 on the grounds that Prior Art 1 discloses elements corresponding to Elements 1, 2 and 4, and Prior Art 2 discloses an element corresponding to Element 3. Given this, it is hard to expect the Plaintiff to consider whether the Claimed Invention lacks inventiveness over a completely different combination between the element in Prior Art 1 that corresponds to Element 4, and the elements in Prior Art 2 that correspond to Elements 1, 2 and 3 when making amendments to the Claimed Invention or submitting arguments on the point.
4) The Plaintiff is likely to cite different elements to argue that the Claimed Invention does not lack inventiveness when responding to the ground of rejection cited in the IPTAB decision and to the Defendant’s argument in this action, and is likely to attempt to amend the specification in different ways. Indeed, the Plaintiff argues that, had the Defendant notified the alleged ground of rejection raised in the litigation before, it would have amended the interface angle range by excluding the angle of 3°, the boundary of the range, in order to overcome the ground of rejection.
5) The ground of rejection raised by the Defendant in this litigation is similar in reasoning to the ground of the First Final Rejection, which vacated by IPTAB on the following grounds:
“Although the Cited Reference discloses the angle (θ) formed by the slant face portion of the wedge part and the normal of the light output plane is in a range of between 3° and 15°, which overlaps with the boundary of the interface angle range in the Claimed Invention (i.e., when the interface angle is equal to 3°), the Cited Reference still discloses that in the case the angle (θ) formed by the slant face portion of the wedge part and the normal of the light output plane is less than 3°, the diffused light beam from the light source cannot reach sufficiently to the observer front side so that the luminance improving effect cannot be obtained and also discloses that in order to maintain the front side luminance using the view angle controlling sheet of the present invention, the preferable range of the angle (θ) is 3°-15° or less. Thus, the Cited Reference explicitly excludes the feature of Claim 1 setting the interface angle to a range of less than 3° by teaching to set the interface angle to a range of 3° or higher. As such, those skilled in the art could not have easily conceived Claim 1 in view of the corresponding element of the Cited Reference.”
In light of the above, the Plaintiff would have hardly anticipated that the same ground of rejection as before would be raised relying on Prior Art 2 which discloses similar technical matters to the Cited Reference.
(C) Therefore, the Defendant’s argument that the IPTAB decision was proper when it found Claim 1 lacks inventiveness based on Prior Art 2 or the combination of Prior Arts 1 and 2 interferes with the Plaintiff’s procedural rights and is hereby rejected.
3) However, we will still review whether Claim 1 lacks inventiveness based on Prior Art 2 as the primary reference below.
B. Element-by-element Comparison between Claim 1 and Prior Art 2
C. Summary of Comparison
1) Claim 1 and Prior Art 2 are the same as each other in terms of: (i) Element 1, i.e., a light control film (a viewing angle control sheet) comprising a light input surface (a surface where the lens part and a light beam side base sheet contact), a light output surface (a surface where the lens part and an observer side base sheet contact), a transmissive region (the lens part), an absorptive region (a wedge part) and a first interface (a slant face where the wedge part and the lens part contact); (ii) Element 2, i.e., an interface angle θ1 defined by the first interface and a direction perpendicular to the light output surface (an angle θ formed between the slant face where the wedge part and the lens part contact and the norman( � and (iii) Element 3, i.e., the difference in the index of refraction between the transmissive region and the absorptive region (i.e., N1<N2) being not less than 0.005 (the refractive index difference between the light transmissive resin, as the material comprising the lens part, and the material comprising the wedge part is to be N2-N1, e.g., a lens part refractive index of 1.56 and a wedge part refractive index of 1.48).
2) With respect to Element 4, Claim 1 specifies the interface angle θ1 as being less than 3 degrees, while Prior Art 2 discloses that the angle between the slant face where the wedge part and the lens part contact and the normal is in the range of 3°≤θ≤15°.
D. Whether Those Skilled in the Art Would Easily Overcome the Difference
In view of the following as found based on the disclosure of each of Plaintiff’s Exhibits 7 to 8 and Defendant’s Exhibit 5 together with the purport of the overall arguments, the foregoing difference would not have been easily overcome by those skilled in the art.
1) The Claimed Invention relates to a light control film that increases the axial brightness of light and enhances brightness uniformity within the viewing angle, while providing a sharp viewing cutoff angle. With respect to Element 4, setting the interface angle θ1 to within the range of θ1≤3° is to form grooves with a relatively high aspect (H/W), thereby providing a sharper image cutoff at lower viewing angles (see Defendant’s Exhibit 5, paragraphs [0015] and [0027]).
2) An objective of Prior Art 2 is to provide an inexpensive viewing angle control sheet that is effective in preventing peeping or reflection among others, while providing a high light beam transmittance to the observer side so as to provide efficient light utilization (see Plaintiff’s Exhibit 8, paragraph [0004]). Further, the specification of Prior Art 2 states as follows:
…, in the case the angle θ formed by the slant face portion of the wedge part and the normal of the light output plane is less than 3°, the diffused light beam from the light source cannot reach sufficiently to the observer front side so that the luminance improving effect cannot be obtained. On the other hand, in the case θ is more than 15°, the area of the lens part that the diffused light beam from the light source is transmitted becomes too small and the luminance is lowered. In order to maintain the front side luminance using the viewing angle control sheet of the present invention, the preferable range of θ is 3° or more and 15° or less (See Plaintiff’s Exhibit 8, paragraph [0009]).
According to the foregoing description, Prior Art 2 intends to obtain an effect of improved front side luminance by limiting the angle (θ) formed by the slant face portion of the wedge part and the normal to the range of 3°≤θ≤15° to allow the diffused light to fully reach in the front direction. On the other hand, while Prior Art 2 has an objective of preventing peeping or reflection, it is different from Claim 1 in terms of the numerical range of the interface angle and thus is not found to have an effect in providing a sharper image cutoff at lower view angles like in Claim 1. Therefore, Claim 1 and Prior Art 2 are different in terms of the technical problem to be solved in view of the interface angle and of the effect resulting from the interface angle.
3) Although the angle (θ) formed by the wedge part and the normal in Prior Art 2 overlaps with the interface angle (θ1) in Claim 1 when the interface angle is in the range of 3 degrees, this numerical value is no more than a boundary between the numerical range of the two inventions. Further, the numerical limitations suggested by the two inventions and the resulting effects therefrom are different from each other. Thus, the feature of Prior Art 2 residing in limiting the angle formed by the slant face portion of the wedge part to the range of 3°≤θ≤15° is not substantially the same as Element 4 of Claim 1. Further, those skilled in the art would not have easily reached Element 4 of Claim 1 in view of Prior Art 2.
4) The Defendant argues that the method of removing the total reflection of light by adjusting the interface angle such that it is greater than 0° had been a well known technology that those skilled in the art would have easily refer to and overcome the foregoing difference. The disclosure of Defendant’s Exhibits 8 to 9 alone, however, is not sufficient to show that removing the total reflection of light by adjusting the interface angle to be higher than 0° had been well known in the art at the time of filing.
5) The Defendant argues that the foregoing difference would have been easily overcome by those skilled in the art by combining Prior Art 1 and Prior Art 2 since Prior Art 2 considers the numerical range of 0°＜θ＜3° in view of its disclosure of a physical strength and manufacturing advantages according to the angle (θ) larger than 0° and Prior Art 1 discloses the included wall angle less than 6° (i.e., the interface angle less than 3°). Prior Art 2 states that “since the wedge part is substantially isosceles trapezoidal or trapezoidal unsymmetrical in the right and left direction, the vertex of the upper bottom surface of the wedge part can be an obtuse angle so that the die for producing the wedge part, or the like can be produced easily, and furthermore, the strength of the wedge part can be improved so as to produce a high quality view angle controlling sheet (including a film) can be produced stably” (see Plaintiff’s Exhibit 8, paragraph [0008]). This description, however, is no more than showing that the wedge part's strength may be improved depending on its shape. In view of this, those skilled in the art would not have easily reached the interface angle in Element 3. Further, the technical problem in Prior Art 2 is to maintain a front side luminance by adopting a predetermined angle (θ) range, and it recognizes the difficulty of improving the front side luminance when the included wall angle is less than 6° as in Prior Art 1 (i.e., when the interface angle is less than 3°) (see Plaintiff’s Exhibit 8, paragraph [0009]). Further, Prior Art 2 does not provide any other portion suggesting or motivating the introduction of the element in Prior Art 1 relating to the included wall angle. Accordingly, those skilled in the art would not have easily overcome the foregoing difference by combining Prior Art 1 and Prior Art 2.
E. Summary of the Analysis
Therefore, the alleged lack of inventiveness when Prior Art 2 is relied upon as the primary reference constitutes a new ground of rejection, for which the Plaintiff was not given an opportunity to respond, and may not be raised in the litigation. Even if it is concluded to the contrary, Claim 1 still would not have been easily conceived by those skilled in the art in view of Prior Art 2 or the combination of Prior Art 1 and Prior Art 2, and thus does not lack inventiveness.
5. Conclusion
In light of the above, the IPTAB decision contrary to the foregoing is erroneous and the Plaintiff's request to revoke the IPTAB decision is well-grounded and thus granted. Decision entered as ordered.
Presiding Judge Hwansoo KIM
Judge Jootag YOON
Judge Hyunjin CHANG
1) A light control film, comprising:
a light input surface and a light output surface opposite the light input surface; alternating transmissive and absorptive regions disposed between the light input surface and the light output surface, each transmissive region having an index of refraction N1, and each absorptive region having an index of refraction N2, where N1-N2 is not less than 0.005; a first interface between a transmissive region and an adjacent absorptive region; and an interface angle θ1 defined by the first interface and a direction perpendicular to the light output surface, where θ1 is not greater than 3 degrees.
2) The description in parenthesis refers to the element in prior art corresponding to Claim 1. The same applies in Section 4.C. below.