| 摘要 |
PURPOSE:To achieve at the same time detailed observation and long-time indication observation by indicating with small compression ratio the information obtained by probing for the past in a relatively new range and with large compression ratio the information that is older than the above mentioned information. CONSTITUTION:The transmission of ultrasonic wave is performed by a transmission trigger from a transmission trigger generation circuit 3 which is based on the pulse sent from a control pulse generation circuit 2. Received signal is, after amplified by an amplification circuit 4, stored in a memory circuit 6 via an A/D converting circuit 5. In writing in the memory circuit 6, the order of writing is progressively changed as ultrasonic pulses are transmitted and old information is compressed. The information retrieved from the memory circuit 6 is displayed on a CRT11 through a color converting circuit and D/A converting circuits 29-31. |
