| 摘要 |
PURPOSE:To perform reliable detection with high durability and high stability by detecting a light-and-dark pattern part provided to the outer periphery of a focus ring and a zoom ring by a detecting means provided at a specific position. CONSTITUTION:Two light-and-dark pattern array parts 14a and 14b and focus distance numbers 15 are arranged on the outer periphery of the focus ring 11. A black frosted paint is applied over the outer peripheral surface of the focus ring 11 and the focus distance numbers 15 and light-and-dark pattern parts 14a and 14b are provided on the same periphery and a direct silk print is made on the focus ring 11 by using white paint. Infrared rays 25a and 25b are emitted by light emitting diodes 24a of photosensors 20a and 20b all the time, and the infrared rays 25a is reflected by a white part of the light-and-dark pattern part 18a of the zoom ring 12; and its reflected light is incident on the photosensor 20a, whose phototransistor 24b detects the infrared ray 25a. Thus, the infrared rays are detected corresponding to the light-and-dark pattern to detect the position of the zoom ring 12. |
