在球型攝影機(Speed Dome Camera)之應用設計上，由於電線滑動環(Slip Ring)能令訊號傳輸的二端線路在進行持續旋轉的情況下維持訊號傳輸之能力，所以球型攝影機通常使用電線滑動環來解決持續旋轉可能引發的線路捲繞之問題，讓球型攝影機可以持續朝同一方向進行旋轉拍攝。但是，電線滑動環的價格十分昂貴，並且價格會隨著通過的訊號線數而遞增，因此，過多的訊號線數將加重整體訊號傳輸設備之成本負擔。本論文提出一新穎且進步的數位攝影機之訊號傳輸架構，其利用影像訊號編碼(Encode)單元將數位影像訊號編碼,再由並列方式轉換序列方式以低電壓差動訊號格式傳輸，以達到減少通過電線滑動環之訊號線數之效果，由通過電線滑動環的低電壓差動訊號解碼還原成數位影像訊號，再透過影像訊號解碼(Decode)單元解出原訊號格式。藉此同時滿足高品質影像輸出及低成本之目的。 所提之訊號傳輸架構包含4個單元：(1)數位影像編碼器輸出單元，為提供數位影音訊號；(2)電線滑動環單元，為提供連接該數位影像訊號，具兩端訊號傳輸；(3)並列訊號轉序列訊號單元(Serializer/Deserializer unit)，可將該數位影像訊號編碼,由並列方式轉換為序列方式及序列方式轉並列方式並以低電壓差動訊號傳輸；以及(4)第二端連接影像訊號解碼單元，讀取第一端數位原始影像訊號並傳輸。在技術與應用上，所提之訊號傳輸架構可以有效的減少電線滑動環的訊號線數。 The slip ring has the ability to maintain the signal transmission between two terminal points when it rotates continuously in the same direction. Therefore the speed dome camera usually uses the slip ring to solve the rotation problem that the electric wire may cause coils continuously. The slip ring can let the speed dome camera continuously rotate in the same direction to capture image. However, the price will be increased progressively as the signal lines passed are counted. Too many signal line counts the cost that will aggravate the transmission equipment of whole system. In this thesis, a new technology for the image signal transmission equipment is proposed so that the number of slip rings is reduced effectively. The digital image encode unit encodes the digital video/audio signals and converts them into LVDS (Low-voltage differential signaling). LVDS unit can convert the data format from parallel to serial. Side by side the signal transfer to the signal encodes and decodes unit. And also reduce digital format too many data bits through the slip ring. Use in encode and decode unit to reappear high quality video image functionality. The technology is usually used in CCTV (close-loop circuit TV) system where the speed dome camera is used. The proposed structure can meet the purpose of high-quality image outputting and low cost at the same time. The image signal transmission structure includes 4 units: (1) The digital image encode unit: It offers the audio-video digital signal. (2) The electric wire slip ring unit: It offers the image signal transmission and connection of two terminal points. (3) Serializer/Deserializer unit: It converts the parallel type of image signal into the serial type and transmits them by using LVDS. (4) Second terminal point connects image signal decode unit: It processes raw image signal and transmits. In the technology and application, the proposed signal transmission structure can effectively reduce the number of electric wire slip rings, so it is novel and practicable.
