

References
[1] Patent Publication No. 52-123270, (1976), Accessed 2026/04/07
[2] Patent Publication No. 52-106763, (1977), Accessed 2026/03/30
[3] Patent Publication No. 2001-305249, (2000), Accessed 2026/04/07
[4] Patent Publication No. 2002-148366, (2000), Accessed 2026/04/07
[5] Patent Publication No. 2003-130974, (2001), Accessed 2026/04/07
[6] Eco-Drive Eclisse PRESS RELEASE, (2001), Accessed 2026/04/08
[7] “New Eco-Drive Watch” with Ring-shaped solar cell, The Horological International Correspondence, Vol. 46, No. 3, (2002), pp.32-42
[8] Citizen Watch Catalog 2002 Vol.1, (Citizen Watch Co. Ltd., 2002), pp.4
[9] “New Eco-Drive Watch” with Ring-shaped solar cell, The Horological International Correspondence, Vol. 46, No. 3, (2002), pp.34
[10] “New Eco-Drive Watch” with Ring-shaped solar cell, The Horological International Correspondence, Vol. 46, No. 3, (2002), pp.34,36
[11] “New Eco-Drive Watch” with Ring-shaped solar cell, The Horological International Correspondence, Vol. 46, No. 3, (2002), pp.39
[12] 2004 Edition Citizen Watch Technical Guide, (Citizen Watch Co. Ltd., 2004), pp.11,13
[13] The evolution of RING SHAPED SOLAR, (2002), Accessed 2026/04/10
[14] Citizen Watch Catalog 2002 Vol.2, (Citizen Watch Co. Ltd., 2002), pp.25
[15] Citizen Watch Catalog 2003 Vol.1, (Citizen Watch Co. Ltd., 2003), pp.32
[16] Patent Publication No. 2011-038911, (2011) Accessed 2026/04/10
[17] Patent Publication No. 2010-276611, (2010), Accessed 2026/04/10
[18] Patent Publication No. 2013-029469, (2013), Accessed 2026/04/10
[19] Patent Publication No. 2010-210295, (2010), Accessed 2026/05/10
[20] Eco-Drive RING – Debuting in 2012, (2012), Accessed 2026/05/10
[21] “Product Introduction Eco-Drive RING”, The Horological International Correspondence, Vol. 56, No. 207, (2012), pp.85
[22] “Technical Report Development of a ring-shaped solar watch driven by light received from the side of the case”, The Horological International Correspondence, Vol. 57, No. 208, (2013), pp.17
[23] “Technical Report Development of a ring-shaped solar watch driven by light received from the side of the case”, The Horological International Correspondence, Vol. 57, No. 208, (2013), pp.15
[24] “Technical Report Development of a ring-shaped solar watch driven by light received from the side of the case”, The Horological International Correspondence, Vol. 57, No. 208, (2013), pp.18
[25] Citizen Watch Catalog 2013, (Citizen Watch Co. Ltd., 2013), pp.71
[26] 2016 Edition Citizen Watch Technical Guide, (Citizen Watch Co. Ltd., 2016), pp.27, 32