Dynamical quantity sensor

Abstract

This invention provides a dynamical quantity sensor having a novel structure, wherein first beams 3, 4, 5, 6 are extended from side walls of a recess 2 of a substrate 1, and an intermediate support member 7 is disposed on the first beams 3, 4, 5, 6. Second beams 8, 9, 10, 11 extending in a direction crossing substantially perpendicularly the first beams 3, 4, 5, 6 are disposed on the intermediate support member 7, and a weight 12 is disposed on the second beams 8, 9, 10, 11. Opposing electrodes 17 and 19 and opposing electrodes 18 and 20 are used as electrodes for excitation, and opposing electrodes 13 and 15 and opposing electrodes 14 and 16 are used as electrodes for detecting an angular velocity. The movement of the weight 12 resulting from the application of the angular velocity is detected.

Description

[0001]This is a continuation application Ser. No. 09 / 035,018, filed Mar. 5, 1998 now U.S. Pat. No. 6,128,953 the entire contents of which is hereby incorporated by reference which is a Divisional of application Ser. No. 08 / 578,371 filed Dec. 26, 1995 now U.S. Pat. No. 5,734,105, which is a File Wrapper Continuation of 08 / 135,498 filed Oct. 13, 1993 now ABN.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]This invention relates to a dynamical quantity sensor for detecting a dynamical quantity such as an angular velocity, acceleration, or the like.[0004]2. Description of the Related Art[0005]A tuning fork type device or a tuning plate type device using a piezoelectric device has been known in the past as a device for detecting a yaw rate by utilizing the Coriolis force.[0006]However, such a device requires machining of a complicated shape and bonding of a piezoelectric device, and is not therefore free from the problems that the reduction of size and cost of production ...

AI Technical Summary

Benefits of technology

The present invention provides a new structure for a dynamical quantity sensor that can be easily made using micro-machining techniques. This structure allows for smaller size, lower cost, and higher precision. The sensor has a weight, anchor portions, connecting portions, and peripheral members. The weight can move in two directions inside a plane in parallel with the substrate. The sensor can detect the movement of the weight caused by a dynamic quantity. The first embodiment uses L-shaped beams to support the weight, and the movement is detected by detecting the deformation of the beams. The second embodiment uses first and second beams to support the weight, with a movable intermediate support member and the weight on the second beams. The weight can move due to deformation of the first or second beams, and the movement is detected to determine the dynamic quantity.

Problems solved by technology

However, such a device requires machining of a complicated shape and bonding of a piezoelectric device, and is not therefore free from the problems that the reduction of size and cost of production and accomplishment of higher precision are difficult.

A yaw rate sensor according to the prior art comprises piezoelectric ceramics, for example, and detects the yaw rate by utilizing the Coriolis force, but has been difficult to reduce size and the cost of production.

Accordingly, there remain the problems yet to be solved that the construction is complicated and the production is difficult.

In view of the production of the sensor device by micro-machining, however, it is quite impossible to accomplish the production method of such a sensor device.

Images