This paper reports a 30-inch scale roll-to-roll production process for high-quality graphene films grown on Cu substrates using chemical vapor deposition (CVD). The process involves multiple roll-to-roll transfers and wet chemical doping, which significantly enhance the electrical properties of the graphene films. The resulting graphene films exhibit a sheet resistance of approximately 30 Ω/sq at a transparency of about 90%, surpassing commercial transparent electrodes like indium tin oxide (ITO). Monolayer graphene films show even lower sheet resistances of ~125 Ω/sq with 97.4% optical transmittance and exhibit the half-integer quantum Hall effect, indicating their high quality. The practical application of these graphene films is demonstrated through the fabrication of a touch screen panel device, which demonstrates superior mechanical and electrical performance compared to ITO-based panels. The flexibility and scalability of the CVD graphene production process, combined with the roll-to-roll methods, are expected to enable large-scale commercial production and application of graphene transparent electrodes. The paper also discusses the challenges and solutions in the roll-to-roll transfer process, including the adhesion of polymer supports, Cu etching, and dry transfer onto target substrates. Additionally, it explores the effects of chemical doping, particularly with nitric acid (HNO3), on the electrical properties of the graphene films. The study concludes with a detailed analysis of the graphene films' optical and electrical characteristics, as well as their potential for commercial use in flexible electronics.This paper reports a 30-inch scale roll-to-roll production process for high-quality graphene films grown on Cu substrates using chemical vapor deposition (CVD). The process involves multiple roll-to-roll transfers and wet chemical doping, which significantly enhance the electrical properties of the graphene films. The resulting graphene films exhibit a sheet resistance of approximately 30 Ω/sq at a transparency of about 90%, surpassing commercial transparent electrodes like indium tin oxide (ITO). Monolayer graphene films show even lower sheet resistances of ~125 Ω/sq with 97.4% optical transmittance and exhibit the half-integer quantum Hall effect, indicating their high quality. The practical application of these graphene films is demonstrated through the fabrication of a touch screen panel device, which demonstrates superior mechanical and electrical performance compared to ITO-based panels. The flexibility and scalability of the CVD graphene production process, combined with the roll-to-roll methods, are expected to enable large-scale commercial production and application of graphene transparent electrodes. The paper also discusses the challenges and solutions in the roll-to-roll transfer process, including the adhesion of polymer supports, Cu etching, and dry transfer onto target substrates. Additionally, it explores the effects of chemical doping, particularly with nitric acid (HNO3), on the electrical properties of the graphene films. The study concludes with a detailed analysis of the graphene films' optical and electrical characteristics, as well as their potential for commercial use in flexible electronics.