File:US Patent 3118022 - Gerhard M. Sessler James E. West - Bell labs - electroacustic transducer - foil electret condenser microphone 1962 1964 - pages 1-3.png
Jump to navigation
Jump to search
Size of this preview: 800 × 395 pixels. Other resolutions: 320 × 158 pixels | 640 × 316 pixels | 1,024 × 506 pixels | 1,280 × 632 pixels | 3,964 × 1,958 pixels.
Original file (3,964 × 1,958 pixels, file size: 207 KB, MIME type: image/png)