Patent ID: 8934162
Filing Date: 2015-01-13
Classification: G03B

Abstract:
1. A diaphragm device comprising: a board including an opening; a step motor including a teeth portion, and rotatable and stoppable at an interval of a predetermined step angle; a transmitting member including a driven teeth portion meshing the teeth portion, and capable of rotating and stopping in response to a drive force of the teeth portion; a drive ring capable of rotating and stopping in response to a drive force of the transmitting member; and a blade capable of stopping at a receding position to recede from the opening or at an aperture position to cover at least a part of the opening, in response to a drive force of the drive ring, wherein the drive ring includes a drive pin engaging the blade, and a driven pin, wherein the drive pin and the driven pin are provided to stand on the same surface of the drive ring, wherein the transmitting member includes a cam slot engaging the driven pin, wherein a relationship between a rotational amount of the transmitting member and a rotational amount of the drive ring is nonlinear, wherein a first interval between a first stop position of the drive ring and a second stop position of the drive ring is larger than a second interval between a third stop position of the drive ring and a fourth stop position of the drive ring, wherein the first stop position of the drive ring is a minimum aperture stop position of the drive ring in a minimum aperture state where an aperture diameter of the opening is minimum, wherein the second stop position of the drive ring is adjacent to the first stop position of the drive ring, wherein the third stop position of the drive ring is adjacent to the fourth stop position of the drive ring, and wherein the third stop position of the drive ring and the fourth stop position of the drive ring are other than in the minimum aperture state.