Microgyroscope tunable for translational acceleration

• US 20040069062A1
• Filed: 08/07/2003
• Published: 04/15/2004
• Est. Priority Date: 10/12/2002
• Status: Active Grant

• Current Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Cho, Jin-Woo
• Granted Patent: US 6,860,150 B2
• Time in Patent Office: Days
• US Class Current: 73/504.12
• CPC Class Codes: G01C 19/5762 the sensing mass being connected to a driving mass, e.g. driving frames

Abstract

A microgyroscope tunable against an external translational acceleration includes an oscillating mass floating over a wafer to oscillate in a first direction, a driving electrode for oscillating the oscillating mass, a sensing mass oscillating together with the oscillating mass and concurrently moving in a second direction, wherein the second direction is perpendicular to the first direction, a sensing electrode for sensing a motion of the sensing mass, and a sensing electrode supporting portion for movably securing the sensing electrode so that the sensing electrode can move in the second direction with the sensing mass. A microgyroscope according to the present invention is able to prevent sensing signals due to an external disturbance, such as noise or impulse.

Claims

1. A microgyroscope tunable against an external translational acceleration, comprising:

an oscillating mass floating over a wafer to oscillate in a first direction;

a driving electrode for oscillating the oscillating mass;

a sensing mass oscillating together with the oscillating mass and concurrently moving in a second direction, wherein the second direction is perpendicular to the first direction;

a sensing electrode for sensing a motion of the sensing mass; and

a sensing electrode supporting portion for movably securing the sensing electrode so that the sensing electrode can move in the second direction with the sensing mass.

2. The microgyroscope as claimed in claim 1, wherein the sensing electrode supporting portion comprises a sensing electrode elastic body elastically disposed between the sensing electrode and the wafer for moving the sensing electrode in the second direction.

3. The microgyroscope as claimed in claim 2, wherein a resonant frequency of the sensing electrode in the second direction is either equal to or similar to a resonant frequency of the sensing mass in the second direction.

4. A microgyroscope tunable against an external translational acceleration, comprising:

outer gimbals floating over a wafer to oscillate in a first direction;

a plurality of first comb units arranged on an external side of the outer gimbals;

at least one driving electrode unit having a plurality of second comb units arranged between the first comb units at predetermined intervals to oscillate the outer gimbals;

inner gimbals movably arranged in the outer gimbals to oscillate together with the outer gimbals, while concurrently moving in a second direction, wherein the second direction is perpendicular to the first direction;

a plurality of third comb units arranged in the second direction in one or more divisions defined in the interior of the inner gimbals;

at least one sensing electrode unit arranged in the divisions of the inner gimbals, and having a plurality of electrode comb units that are arranged between the third comb units of the divisions at predetermined intervals; and

a sensing electrode supporting portion for movably securing the sensing electrode unit such that the sensing electrode unit is moved in the second direction with the inner gimbals.

5. The microgyroscope as claimed in claim 4, wherein the sensing electrode supporting portion comprises a sensing electrode beam elastic body elastically disposed between the sensing electrode unit and the wafer for oscillating the sensing electrode unit in the second direction.

6. The microgyroscope as claimed in claim 5, wherein the sensing electrode beam elastic body comprises:

an anchor secured on the wafer and extending upwards; and

an elastic horizontal beam elastically disposed to connect both sides of the anchor with the sensing electrode unit.

7. The microgyroscope as claimed in claim 6, wherein a resonant frequency of the sensing electrode in the sensing direction is either equal to or similar to a resonant frequency of the inner gimbals in the second direction.

8. The microgyroscope as claimed in claim 7, wherein the first, the second and the third comb units each comprise a plurality of combs.

9. The microgyroscope as claimed in claim 8, wherein the interior of the inner gimbals is defined as a single division where a plurality of third comb units are respectively arranged in both sides thereof, and

the sensing electrode unit comprises one sensing electrode that is arranged in the single division of the interior of the inner gimbals, and has a plurality of electrode comb units arranged between the third comb units at predetermined intervals.

10. The microgyroscope as claimed in claim 8, wherein the interior of the inner gimbals is defined as more than two divisions where a plurality of third comb units are respectively arranged in both sides thereof, and

the sensing electrode unit comprises a plurality of sensing electrodes that are respectively arranged in the divisions of the interior of the inner gimbals, and has a plurality of electrode comb units arranged between the third comb units at predetermined intervals.