自2015年起，歐洲專利局（EPO）與美國專利商標局（USPTO）分別放棄了各自使用的歐洲專利分類（ELCA）與美國專利分類（USPC），開始採用一套新的分類架構─合作專利分類（CPC），但仍同步提供目前最多國家使用的國際專利分類（IPC）分類號。有鑑於專利分析者常以美國專利、以及其IPC分類號作為技術分析的基礎，本研究主要目的係比較美國專利現行的兩套專利分類系統下二者的差異程度。

因此，本研究收集了美國專利商標局於2017年公告的318,829件發明專利，依據實務的專利分類號分析方式，比較這些發明專利的IPC與CPC分類號的三階、四階、乃至五階以下階層的差異。本研究發現，將分類號簡化到其三階或四階部分時，IPC與CPC分類號其實有一定的差異，這表示進行美國專利分析時，區別以IPC或CPC分類號為標的是有意義的。

而本研究也進一步發現，CPC雖然有較IPC為多的三階與四階分類號，但採取三階或四階不同的IPC、CPC分類號時，CPC反而有比IPC集中的現象。因此實務的專利分類號分析，如採高階（如三階或四階）分類號者，似以採取CPC為佳。本研究的貢獻在於利用分類號進行數據挖掘與分析者，客觀地建立採用IPC或CPC分類號作為分析標的的有效性。本研究的發現可以讓其分析結果，不論是專利的檢索、技術發展趨勢的預測、技術擴散路徑的探勘等，得到更精確與可靠的結果。

Since 2015, the European Patent Office (EPO) and the United States Patent and Trademark Office (USPTO) have abandoned their respective European Patent Classification (ELCA) and US Patent Classification (USPC) and begin to adopt a new classification system-Cooperative Patent Classification (CPC), but still provide the International Patent Classification (IPC) currently used by most countries. In view of the fact that patent analysts often use US patents and IPC classification symbols as the basis for technical analysis, the main purpose of this study is to compare the differences between the two patent classification systems applied to the US patents.

Therefore, this study collects 318,829 utility patents issued by USPTO in 2017 and compares differences on the third-level, fourth-level, and fifth-level-and-below IPC and CPC classification symbols of these utility patents according to practical patent classification analysis methods. This study finds that there are certain differences between IPC and CPC classification symbols when the classification symbols are simplified to their third-level or fourth-level parts. This means that when analyzing US patents, it is meaningful to distinguish the IPC or CPC classification symbols.

Then, the study further finds that, even though CPC has more third-level and fourth-level classification symbols than IPC, but US patents on the average have more different third-level or fourth-level IPC symbols than their CPC symbols. US patents have a more centralized phenomenon in terms of their CPC symbols than their IPC symbols. Therefore, it seems that, for the analysis of the patent classification symbols, CPC seems to be a better choice for higher-level classification symbols. The contribution of this study lies in that it provides an objective assessment on the validity of IPC or CPC classification symbols when conducting patent data mining and analysis. The findings of this study may help technology analyses, whether they are about patent search, prediction of technology development trends, and exploration of technology diffusion paths, to obtain more accurate and reliable results.

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網頁部分
EPO Cooperative Patent Classification。網址http://www.cooperativepatentclassification.org/index.html
USPTO Patents View。網址http://www.patentsview.org/download/
USPTO Bulk Data Storage System。網址https://bulkdata.uspto.gov/
WIPO International Patent Classification。網址http://www.wipo.int/classifications/ipc/en/