First, in the stage of operation automation in 1960s, it was mainly to manage and control the library business by single machine, to realize the automation of library business management and serve the library staff;
The second is the establishment stage of the comprehensive library automation system in the 1970s, which is mainly due to the establishment of a large-scale public online catalogue as the foundation and core, realizing the comprehensive automation of business management functions and the integration of automation functions;
Third, the formation stage of the networked integrated information delivery system in 1980s, based on the networked information service structure, aimed at network users and realized various retrieval and delivery services of multiple information sources for users;
Fourth, since the 1990s, it is developing towards a digital and intelligent user information system, mainly taking information digitization as the core ——TL and taking the network as the technical environment to realize the fundamental transformation of the business operation, management mode and service mode of the whole library system (Yang Xiangming, 200 1).
Some scholars call the merger of the first two stages the primary stage of library automation development, which is marked by the official release of MARCII's machine-readable catalogue by the Library of Congress. It is considered that the second stage (or transitional stage) is a new stage for libraries to provide global integrated electronic document information services on the Internet. At this stage, around 1985, marked by the application of C-RoM and LAN in the library, people can access the library's machine-readable catalogue, CD-ROM database and retrieval system in the library, office, laboratory and even at home, which makes the large-scale literature information center that appeared in the 1970s fully play its benefits. Especially in the 1990s, the rapid development of the Internet pushed the electronic literature information on the library network to a new stage of global service. The third stage is the advanced stage of library automation development, namely the digital library stage (Yang Zongying and Zheng Qiaoying, 2000).
Some scholars believe that the core of the first generation digital library is automation construction, and its task is bibliography management based on MARC. Its disadvantage is that it can only provide guidance information for paper books, but not for other electronic secondary documents. The main feature of the second generation digital library is the application of a large number of distributed electronic literature resources provided through the Internet. To some extent, it realizes the unified utilization of different types of information resources and the function of content-based information chain, and realizes the multi-mode information digitization mechanism for specific information resources. The deficiency of the second generation digital library is that it can't fully meet the needs of readers for personalized and active information services under the network environment, and it also lacks the function of effectively sorting out the huge and chaotic network information. For the third generation digital library, it is still in the research and planning stage (Zhang Chengyu, 2003).
In a word, the academic division of the development stages of digital libraries is not consistent and there are differences. After comparison, the author thinks that it is reasonable for Han Yi and Yang Xiaoqiong to divide the development process of digital library into three stages according to the basic technology and ideas of digital library construction: management information system based on automation, electronic library based on LAN and MAN, and digital library based on information superhighway. The following is a brief introduction to this division of labor theory (Han Yi, 2005). ...