Light intensity control devices and optical instruments

Abstract

To provide a light intensity adjustment device that reduces blade curvature and improves aperture accuracy. [Solution] In order to solve the above problems, the light intensity adjustment device of the present invention is a light intensity adjustment device comprising a base plate 40 having a fixed aperture through which light passes and a plurality of cam grooves, a plurality of aperture blades 10 arranged in the circumferential direction of the fixed aperture to form a variable aperture through which the light passes, a drive ring 20 that rotates in the circumferential direction of the fixed aperture and transmits driving force to the aperture blades 10 to rotate the plurality of aperture blades 10 so as to change the size of the variable aperture, and a drive source unit 1 that rotates the core drive ring 20 is supported by a retaining plate 30, wherein the aperture blades 10 have protrusions 13 and operate while being restricted along a rail shape 27 provided on the drive ring.

Claims

1. A base member having a fixed opening through which light passes, A plurality of aperture blades are arranged in the circumferential direction of the fixed aperture to form a variable aperture through which the light passes, A light intensity adjustment device having a drive ring that rotates in the circumferential direction of the fixed aperture and transmits driving force to the aperture blades, thereby rotating the plurality of aperture blades to change the size of the variable aperture, A light intensity adjustment device characterized by having a convex shape positioned between the drive pin and the cam pin on the drive ring side of the aperture blades, and having a rail shape provided on the drive ring in the range in which the convex shape of the aperture blades fits and slides from wide open to small aperture, wherein the rail shape is deeper than the convex shape of the aperture blades from wide open to intermediate, and the blade sliding surface is sloped to restrict the convex shape of the aperture blades from intermediate to small aperture.

2. The light intensity adjustment device according to claim 1, characterized in that the rail provided on the drive ring is concave and becomes shallower from wide open to small aperture.

3. The light intensity adjustment device according to claim 1, characterized in that the rails provided on the drive ring have the same number as the blades and are arranged at equal intervals in the circumferential direction.

4. The light intensity adjustment device according to claim 1, characterized in that the rail provided on the drive ring is concave, becoming shallower from wide open to small aperture, and becoming deeper again when the aperture is even smaller.

5. The light intensity adjustment device according to claim 1, characterized in that the convex shape provided on the aperture blades also serves as a gate.

6. An optical instrument comprising a light intensity adjustment device according to any one of claims 1 to 5, and an image sensor for imaging light that has passed through the light intensity adjustment device.

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