[2] In a case where Company A filed a petition for a registration invalidation trial against Party B, the utility model right holder of the registered device “B, which is equipped with a cell phone shield,” on the ground that the nonobviousness of the registered device is denied, and the Korean Intellectual Property Trial and Appeal Board rendered a trial ruling citing the registered device, the case held that the judgment below erred by misapprehending the legal principles, although Article 1 of the registered claim scope of the registered device “the cell phone case in the form of covering the front and rear of the mobile phone in the form of covering the front and rear of the mobile phone, and protecting the external appearance of the mobile phone,” and “the front part of the mobile phone rink” consisting of “the cell phone rink in the form of covering the cell phone and the front part of the mobile phone rink, which is embodied with a permanent seat and cream,” the composition or content of the prior design does not appear to combine it, and it is difficult for an ordinary technician to easily apply the registered device to the cell phone shield with the permanent seat.

1. In order to determine whether the nonobviousness of a device is denied, in light of the scope and content of prior art, the difference between the device subject to the determination of inventive step and prior art, and the technological level of a person with ordinary knowledge in the art to which the device pertains (hereinafter “ordinary engineer”), etc., even though the device subject to the determination of inventive step differs from prior art, it is necessary to examine whether the device could overcome such difference and easily derive the device from prior art. In such cases, the determination of whether the device could be made ex post facto on the premise that the person with ordinary skill becomes aware of the technology described in the specification of the device subject to the determination of inventive step, should not be made on the basis of the premise that the person with ordinary skill could easily easily make the device (see, e.g., Supreme Court Decision 2018Hu12004, Jul. 25, 2019)

2. We examine the above legal principles and records.

A. The name of the device of this case (hereinafter “instant Claim No. 1 design” refers to the device of this case, and other claims are also indicated in the same manner) consisting of “the mobile phone case in which the front and rear sides of the mobile phone are installed on the mobile phone in the form of covering the front and rear side of the mobile phone and protecting the external appearance of the mobile phone” and “the front part of the mobile phone case” consisting of “the front part of the mobile phone No. 1 of the device of this case (hereinafter “the cell phone No. 1 device of this case”) and the front part of the cell phone No. 1 of the cell phone No. 2009, which is embodied by mediating the permanent seat and trike at the location corresponding to the cell phone No. 1.

B. While the prior design 4 uses a shielded stone without shielding function, there is a difference that the design of the instant Claim 1 is embodied by means of permanent seat and cream, and uses a shielded stone with self-shield function, and such difference appears in the prior design 2, which is the shielded stone itself.

C. The instant Claim 1 design is a technical task that “the prevention of malfunction in a license that may occur by milching the front side of the mobile phone case after the front side of the cell phone by using the shielding seat on the cell phone of the mobile phone case at a corresponding point.” On the other hand, the prior design 4 is a technical task to prevent malfunction in a mobile phone case, such as where the cell phone case is closed by external pressure, and the main part of the prior design 4 is to prevent malfunction in a mobile phone, such as where the cell phone key part is divided into the external pressure when the cell phone case is closed, and it is not a solution method to regulate its operation only by the response of the cell phone with the ability and ability, not a physical stimulation, and there is no awareness of the problems that may occur due to the use of the permanent seat if the front part of the mobile phone case is laid behind. In addition, the prior design 2 is a shielding body that can be used in the general electricity and electronic field.

D. The composition or content of the foregoing prior designs does not appear to have the motive or rock to combine them, and it is difficult to view that each description of the evidence Nos. 3 through 5, in the parts of electronic products, of the shielded technology using the shielding board or cream, can easily be applied to the cellular phone case by a person with ordinary skills, on the sole basis of the descriptions of the evidence Nos. 3 through 5.

E. Meanwhile, insofar as the nonobviousness of the instant Claim No. 1 device is not denied, the nonobviousness of the instant Claim Nos. 2 through 4, which is a dependent claim citing the instant Claim No. 1 device, is not denied.

3. The lower court determined as follows.

① The claim scope of the instant Claim No. 1 cannot be deemed to be limited to the composition of milching behind the front side of the mobile phone case. As such, “the effect of preventing erroneous operation that may arise by milching after the rear side of the front side of the mobile phone case” cannot be deemed to be an effect resulting from the composition of the instant Claim No. 1 device. ② The instant Claim No. 2 through No. 4, which is a subordinate claim, can easily derive by combining the instant Claim No. 1 device and the instant Claim No. 2 through No. 4, which are the instant Claim No. 4, with the earlier Claim No. 4, the nonobviousness of the nonobviousness is denied.

4. In so determining, the lower court erred by misapprehending the legal doctrine on determining the inventive step of a utility model, thereby adversely affecting the conclusion of the judgment. The ground of appeal assigning this error is with merit.

5. Therefore, the lower judgment is reversed, and the case is remanded to the lower court for further proceedings consistent with this Opinion. It is so decided as per Disposition by the assent of all participating Justices on the bench.

Justices Min You-sook (Presiding Justice)