# US 5,708,893 A · Microceramic electromagnetic light shutter

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,708,893 A
- Document ID: US5708893A
- Status: Granted
- Kind: A
- Application number: 08/808,897
- Filed: 1997-02-28
- Granted: 1998-01-13
- Earliest claimed: 1997-02-28
- Assignees: Eastman Kodak Company
- Inventors: Edward P. Furlani; Dilip K. Chatterjee; Syamal K. Ghosh
- Web page: https://patentgrep.com/patent/US5708893A

## CPC

- G03B 9/10: Blade or disc rotating or pivoting about axis normal to its plane
- G03B 9/00: Exposure-making shutters; Diaphragms
- G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D)

## Abstract

A microceramic electromagnetic light shutter is disclosed including a unitary ceramic body having an internal cavity. A conductive coil is formed in the internal cavity. The unitary ceramic body defines a first and second bearing structure on it's surface. The unitary ceramic body has a light aperture and first and second recesses. The microceramic electromagnetic light shutter further includes a shutter drive mechanism including a shutter blade and a ferromagnetic element inserted into the first recess and operative to the shutter drive mechanism for applying a torque to the shutter drive mechanism which causes the shutter drive mechanism to move so that the shutter blade is in it's light blocking position. The shutter drive mechanism is mounted in the second recess an in an operative relationship to the coil and ferromagnetic element. The shutter blade is movable between a light blocking and light passing positions relative to the light aperture so that when a drive voltage is applied to the coil a field is created by the coil which provides a torque to the shutter drive mechanism to overcome the torque applied by the ferromagnetic element thereby causing the shutter blade to move to the light passing position. When the drive voltage is discontinued the ferromagnetic element provides a torque on the shutter mechanism causing the shutter blade to return to the light blocking position.

## Claims

### Claim 1

A microceramic electromagnetic light shutter comprising:
(a) a unitary ceramic body having an internal cavity,
(b) a conductive coil formed in said internal cavity;
(c) the unitary ceramic body defining a first and second bearing structure on its surface; the unitary ceramic body having a light aperture therethrough and defining first and second recesses;
(d) a shutter drive mechanism, including a shutter blade;
(e) a ferromagnetic element inserted into said first recess and operative relationship to the shutter drive mechanism for applying a torque to said shutter drive mechanism which causes the shutter drive mechanism to move so that the shutter blade is in its light blocking position; and
(f) the shutter drive mechanism being mounted in said second recess and in operative relationship to the coil and ferromagnetic element, and having a shutter blade which is movable between light blocking and light passing positions relative to the light aperture so that when a drive voltage is applied to the coil, a field is created by the coil which provides a torque to the shutter drive mechanism to overcome the torque applied by the ferromagnetic element thereby causing the shutter blade to move to the light passing position, and when the drive voltage is discontinued the ferromagnetic element provides a torque on the shutter mechanism causing the shutter blade to return to the light blocking position.

### Claim 2 (depends on 1)

A microceramic electromagnetic light shutter according to claim 1 wherein said unitary ceramic body further includes surface features in the form of stop structures that limit the range of motion of said shutter drive mechanism.

### Claim 3 (depends on 2)

A microceramic electromagnetic light shutter according to claim 2 wherein the shutter drive mechanism includes an insert member which a bearing surface, a rotor with a shaft, mounted inside the insert member, a micromagnet fixedly attached to said shaft, and a shutter blade fixedly attached to said micromagnet and with said micromagnet being in operational relation to said coil such that when a voltage is applied to said coil it produces a magnetic field that causes said micromagnet with attached shutter blade to rotate.

### Claim 4 (depends on 3)

A microceramic electromagnetic light shutter according to claim 3 wherein the insert member is made from low friction ceramic material such as MoSi.sub.2 or ZrB.sub.2.

### Claim 5 (depends on 3)

A microceramic electromagnetic light shutter according to claim 3 wherein the shutter blade is made from light metals such as Al, Mg, Al-alloys or alternatively opaque plastics such as nylon, polyethylene or PVC.