Patent ID: 9629552
Date: 2017-04-25
CPC Classifications: A61B,G01B,G02B

Claim:
1. A numerical aperture (NA) controlling unit, comprising: an aperture adjustment unit that adjusts an aperture through which light propagates; and a focus control unit that has an adjustable focal length and that is disposed in a predetermined position with respect to the aperture adjustment unit, wherein the focus control unit focuses light which propagates through the aperture, wherein the aperture adjustment unit comprises: a first chamber that forms a space in which a fluid flows; a first fluid and a second fluid that are accommodated in the first chamber, wherein the first fluid is immiscible with the second fluid, and wherein one of the first fluid and the second fluid is formed of a material having a light-transmitting property and an other one of the first fluid and the second fluid is formed of a material having at least one of a light-blocking property and a light-absorbing property, wherein the aperture through which light propagates is adjustable based on a change of a position of an interface between the first fluid and the second fluid; and a first electrode portion that is disposed inside the first chamber, and wherein a region of the first chamber comprises: a first channel; and a second channel that is disposed above and in parallel with the first channel and that is connected to the first channel, wherein a range of the aperture is defined by a change of a position of a first interface between the first fluid and the second fluid in the first channel and a change of a position of a second interface between the first fluid and the second fluid in the second channel, and wherein the first electrode portion includes at least one electrode disposed in the first channel at a bottommost portion of the first chamber and another at least one electrode disposed in the second channel at a topmost portion of the first chamber, and between which a voltage is applied across an entirety of a height of the first chamber so as to form an electric field in the first chamber, and wherein each of the change of position of the first interface and the change of position of the second interface is caused by the electric field, wherein the first channel is formed by a first substrate on which the at least one electrode is disposed, a second substrate that is spaced apart from the first substrate and that has a first through hole formed in a central portion of the second substrate and a second through hole formed in a peripheral portion of the second substrate, and a first spacer that is disposed to form an internal space between the first substrate and the second substrate, and wherein the second channel is formed by the second substrate, a third substrate on which the another at least one electrode is disposed and which is spaced apart from the second substrate, and a second spacer that is disposed to form an internal space between the second substrate and the third substrate.