JP2002048813A - Capacitance-type acceleration sensor - Google Patents
Capacitance-type acceleration sensorInfo
- Publication number
- JP2002048813A JP2002048813A JP2000235983A JP2000235983A JP2002048813A JP 2002048813 A JP2002048813 A JP 2002048813A JP 2000235983 A JP2000235983 A JP 2000235983A JP 2000235983 A JP2000235983 A JP 2000235983A JP 2002048813 A JP2002048813 A JP 2002048813A
- Authority
- JP
- Japan
- Prior art keywords
- movable electrode
- electrode
- capacitance
- acceleration
- fixed
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
- G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
- G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
- G01P2015/0805—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration
- G01P2015/0822—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration for defining out-of-plane movement of the mass
- G01P2015/0825—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration for defining out-of-plane movement of the mass for one single degree of freedom of movement of the mass
- G01P2015/0828—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration for defining out-of-plane movement of the mass for one single degree of freedom of movement of the mass the mass being of the paddle type being suspended at one of its longitudinal ends
Landscapes
- Pressure Sensors (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、可動電極と固定電
極との間の容量の変化に基づいて印加加速度を検出する
ようにした容量式加速度センサに関する。The present invention relates to a capacitive acceleration sensor for detecting an applied acceleration based on a change in capacitance between a movable electrode and a fixed electrode.
【０００２】[0002]
【従来の技術】この種の容量式加速度センサの一般的な
構成を図４に模式的に示す。このセンサは、所定方向
（図４中の矢印で示すＹ軸方向）へ変位可能な可動電極
１と、このＹ軸方向において可動電極１に対し互いに反
対側にて対向して配置された第１及び第２の固定電極
２、３とを備える。2. Description of the Related Art A general structure of a capacitive acceleration sensor of this kind is schematically shown in FIG. This sensor includes a movable electrode 1 that can be displaced in a predetermined direction (Y-axis direction indicated by an arrow in FIG. 4) and a first electrode that is disposed opposite to the movable electrode 1 on the opposite side in the Y-axis direction. And second fixed electrodes 2 and 3.
【０００３】そして、可動電極１と第１の固定電極２と
の間に第１の容量Ｃ１が形成され、可動電極１と第２の
固定電極３との間に第２の容量Ｃ２が形成されている。
ここで、Ｙ軸方向へ加速度が印加されたときに可動電極
１がＹ軸方向へ変位し、この可動電極１の変位に伴う第
１の容量Ｃ１及び第２の容量Ｃ２の変化（通常は第１の
容量と第２の容量の差動容量変化）に基づいて印加加速
度を検出するようになっている。A first capacitance C1 is formed between the movable electrode 1 and the first fixed electrode 2, and a second capacitance C2 is formed between the movable electrode 1 and the second fixed electrode 3. ing.
Here, when acceleration is applied in the Y-axis direction, the movable electrode 1 is displaced in the Y-axis direction, and changes in the first capacitance C1 and the second capacitance C2 due to the displacement of the movable electrode 1 (normally, The applied acceleration is detected based on the differential capacitance between the first capacitance and the second capacitance).
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、上記の
ような容量式加速度センサにおいては、可動電極に対し
て変位方向即ち所定方向へ変位のオフセットが生じやす
い。すると、このオフセットによって加速度と出力（通
常は上記容量変化を電圧に変換したもの）との直線関係
が崩れ、検出精度が悪化するという問題が発生する。However, in the above-described capacitive acceleration sensor, the displacement of the movable electrode is likely to be offset in the direction of displacement, that is, in a predetermined direction. Then, the linear relationship between the acceleration and the output (normally, the capacitance change is converted into a voltage) is broken by the offset, and a problem occurs that the detection accuracy is deteriorated.
【０００５】例えば、上記図４に示す容量式加速度セン
サを、自動車のサスペンション制御等に使用する場合を
考える。この場合、図４中のＹ軸方向が天地方向（垂直
方向）となり、可動電極１は重力加速度の影響を受け
て、正規の位置から重力加速度方向（図４中の下方）へ
オフセットされた状態となる。For example, consider a case in which the capacitive acceleration sensor shown in FIG. 4 is used for suspension control of an automobile or the like. In this case, the Y-axis direction in FIG. 4 becomes the vertical direction (vertical direction), and the movable electrode 1 is offset from the normal position in the direction of gravitational acceleration (downward in FIG. 4) under the influence of gravitational acceleration. Becomes
【０００６】すると正規の状態では、例えば各容量Ｃ
１、Ｃ２が等しかったもの（Ｃ１＝Ｃ２）が、上記オフ
セットが発生すると、例えばＣ１＜Ｃ２となり、ずれが
生じてしまう。そして、加速度と出力電圧との関係は、
図５に示す様に、正規の状態における直線関係（破線）
からずれを生じ、直線性が悪化し、加速度を正確に検出
しにくくなる。In a normal state, for example, each capacitor C
However, when the offset is generated, the difference between C1 and C2 is equal (C1 = C2), for example, C1 <C2, and a shift occurs. And the relationship between acceleration and output voltage is
As shown in FIG. 5, a linear relationship in a normal state (broken line)
Deviation, the linearity deteriorates, and it becomes difficult to accurately detect the acceleration.
【０００７】本発明は上記問題に鑑み、容量式加速度セ
ンサにおいて、可動電極に発生する変位のオフセットを
抑制し、検出精度を向上させることを目的とする。SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a capacitive acceleration sensor that suppresses a displacement offset generated in a movable electrode and improves detection accuracy.
【０００８】[0008]
【課題を解決するための手段】上記目的を達成するた
め、請求項１の発明では、所定方向へ変位可能な可動電
極（１）と、所定方向において可動電極に対し互いに反
対側にて対向して配置された第１及び第２の固定電極
（２、３）とを備え、可動電極と第１の固定電極との間
に第１の容量が形成され、可動電極と第２の固定電極と
の間に第２の容量が形成されており、加速度が印加され
たときに可動電極が所定方向へ変位し、この可動電極の
変位に伴う第１の容量及び第２の容量の変化に基づいて
印加加速度を検出するようにした容量式加速度センサに
おいて、可動電極と第１の固定電極との間及び可動電極
と第２の固定電極との間の少なくとも一方に静電引力を
発生させるための電気信号を印加することにより、可動
電極における所定方向への変位のオフセット分をキャン
セルできるようになっていることを特徴とする。To achieve the above object, according to the present invention, a movable electrode (1) displaceable in a predetermined direction is opposed to the movable electrode in a predetermined direction on opposite sides. A first capacitor is formed between the movable electrode and the first fixed electrode, and a first capacitor is formed between the movable electrode and the first fixed electrode. The movable electrode is displaced in a predetermined direction when acceleration is applied, and based on a change in the first capacitance and the second capacitance associated with the displacement of the movable electrode. In a capacitive acceleration sensor configured to detect an applied acceleration, an electric force for generating an electrostatic attraction between at least one of a movable electrode and a first fixed electrode and at least one of a movable electrode and a second fixed electrode. By applying a signal, a predetermined direction on the movable electrode Characterized in that it adapted to cancel the offset of the displacement.
【０００９】本発明によれば、可動電極における所定方
向への変位のオフセット分をキャンセルするように、可
動電極と第１の固定電極との間及び可動電極と第２の固
定電極との間の両方またはどちらか一方に静電引力を発
生させるための電気信号を印加することができるため、
可動電極に発生する変位のオフセットを抑制し、検出精
度を向上させることができる。According to the present invention, the distance between the movable electrode and the first fixed electrode and the distance between the movable electrode and the second fixed electrode are set so as to cancel the offset of the displacement in the predetermined direction in the movable electrode. Because an electrical signal for generating electrostatic attraction can be applied to both or one of them,
The offset of the displacement generated in the movable electrode can be suppressed, and the detection accuracy can be improved.
【００１０】ここで、請求項２の発明のように、上記電
気信号としては、可動電極（１）と第１の固定電極
（２）との間、若しくは、可動電極と第２の固定電極
（３）との間に印加される直流電圧とすることができ
る。それにより、可動電極における所定方向への変位の
オフセット分をキャンセルするように、静電引力を適切
に発生させることができる。Here, as in the second aspect of the present invention, the electric signal is generated between the movable electrode (1) and the first fixed electrode (2) or between the movable electrode and the second fixed electrode (2). And 3) can be a DC voltage applied between them. This makes it possible to appropriately generate electrostatic attraction so as to cancel the offset of the displacement in the predetermined direction in the movable electrode.
【００１１】また、請求項３の発明のように、印加加速
度を検出するための周期的に変化する検出用信号が可動
電極と第１及び第２の固定電極との間に印加されるよう
になっている場合、上記電気信号は、この検出用信号と
同期した信号であるものにすることができる。それによ
れば、検出用信号と電気信号が同期しているため、ノイ
ズの発生を抑えることができる。According to a third aspect of the present invention, a periodically changing detection signal for detecting an applied acceleration is applied between the movable electrode and the first and second fixed electrodes. If so, the electric signal can be a signal synchronized with the detection signal. According to this, since the detection signal and the electric signal are synchronized, generation of noise can be suppressed.
【００１２】また、上記請求項１〜請求項３の各発明
は、請求項４の発明のように、所定方向が天地方向に沿
った方向であるセンサに適用した場合に、重力加速度に
より可動電極に発生する変位のオフセットを適切に抑制
することができる。Further, when each of the first to third aspects of the present invention is applied to a sensor in which the predetermined direction is a direction along the vertical direction as in the fourth aspect of the invention, the movable electrode is driven by gravitational acceleration. Can be appropriately suppressed.
【００１３】なお、上記各手段の括弧内の符号は、後述
する実施形態に記載の具体的手段との対応関係を示す一
例である。The reference numerals in parentheses of the above means are examples showing the correspondence with specific means described in the embodiments described later.
【００１４】[0014]
【発明の実施の形態】以下、本発明を図に示す実施形態
について説明する。本実施形態は、自動車等の車体懸架
装置制御にて、天地方向（鉛直方向）の加速度を検出す
る加速度センサに適用したものとして説明する。図１
は、本実施形態に係る容量式加速度センサの構成を模式
的に示す図である。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention. This embodiment will be described as being applied to an acceleration sensor that detects acceleration in a vertical direction (vertical direction) by controlling a vehicle suspension system of an automobile or the like. Figure 1
FIG. 1 is a diagram schematically illustrating a configuration of a capacitive acceleration sensor according to an embodiment.
【００１５】本センサは、梁状の可動電極１及び一対の
固定電極２、３により構成されている。これら各電極１
〜３は、実際には、良く知られているシリコン基板やＳ
ＯＩ（シリコン−オン−インシュレータ）基板等に、半
導体製造技術を用いて形成された櫛歯状のものとするこ
とができる。This sensor comprises a beam-shaped movable electrode 1 and a pair of fixed electrodes 2 and 3. Each of these electrodes 1
3 is actually a well-known silicon substrate or S
A comb-shaped substrate formed on an OI (silicon-on-insulator) substrate or the like by using a semiconductor manufacturing technique can be used.
【００１６】可動電極１は、基部４に固定され、図１中
の矢印にて示すＹ軸方向を天地方向として（図中の上方
が天、下方が地であり、以下、天地方向Ｙという）、水
平方向へ延びるように配置されている。そして、可動電
極１は、基部４に固定された部分を固定端として、自由
端側は天地方向Ｙへ変位可能となっている。The movable electrode 1 is fixed to the base 4, and the Y-axis direction indicated by the arrow in FIG. 1 is the top and bottom direction (the top is the top and the bottom is the ground, hereinafter referred to as the top and bottom direction Y). , So as to extend in the horizontal direction. The movable electrode 1 can be displaced in the vertical direction Y on the free end side, with the portion fixed to the base 4 as a fixed end.
【００１７】固定電極２、３は、天地方向Ｙにおいて可
動電極１を挟んで天側と地側とで可動電極１に対向して
配置された第１の固定電極（天側）２及び第２の固定電
極（地側）３よりなる。各固定電極２、３は、一端側が
基部４に固定され他端側が水平方向へ延びるように、基
部４に片持ち状に支持されている。The fixed electrodes 2 and 3 include a first fixed electrode (top side) 2 and a second fixed electrode (top side) which are arranged opposite to the movable electrode 1 on the top side and the ground side with the movable electrode 1 interposed therebetween in the top and bottom direction Y. (Fixed electrode) 3 (ground side). Each fixed electrode 2, 3 is cantilevered by the base 4 so that one end is fixed to the base 4 and the other end extends in the horizontal direction.
【００１８】ここで、図１中、コンデンサ記号にて示す
様に、可動電極１と第１の固定電極２との間に第１の容
量Ｃ１が形成され、可動電極１と第２の固定電極３との
間に第２の容量Ｃ２が形成されている。そして、天地方
向Ｙの成分を含む加速度が印加されたときに可動電極１
が天地方向Ｙへ変位し、この可動電極１の変位に伴う第
１の容量Ｃ１と第２の容量Ｃ２の変化に基づいて印加加
速度を検出するようになっている。Here, as shown by a capacitor symbol in FIG. 1, a first capacitor C1 is formed between the movable electrode 1 and the first fixed electrode 2, and the movable electrode 1 and the second fixed electrode 2 are formed. The second capacitor C2 is formed between the second capacitor C3 and the second capacitor C3. When the acceleration including the component in the vertical direction Y is applied, the movable electrode 1
Is displaced in the vertical direction Y, and the applied acceleration is detected based on a change in the first capacitance C1 and the second capacitance C2 accompanying the displacement of the movable electrode 1.
【００１９】例えば、可動電極１と第１の固定電極２と
の間に周期的に変化する第１の搬送波（検出用信号）を
印加し、可動電極１と第２の固定電極３との間に第１の
搬送波とは逆相の周期的に変化する第２の搬送波（検出
用信号）を印加した状態で、第１の容量Ｃ１と第２の容
量Ｃ２の差動容量をとり、加速度印加時における当該差
動容量の変化を電圧に変換して出力することで、加速度
検出が可能となっている。For example, a first carrier (detection signal) that changes periodically is applied between the movable electrode 1 and the first fixed electrode 2, and the first carrier wave is applied between the movable electrode 1 and the second fixed electrode 3. In the state where a second carrier wave (detection signal) that periodically changes in phase opposite to that of the first carrier wave is applied, the differential capacitance between the first capacitance C1 and the second capacitance C2 is taken, and acceleration is applied. By converting the change in the differential capacitance at the time into a voltage and outputting the voltage, the acceleration can be detected.
【００２０】ところで、車体懸架装置制御にて天地方向
Ｙの加速度を検出する場合、システムの機能上（例：ス
カイフック制御）、比較的低い加速度を検出する必要が
あり、加速度センサとしては、高感度であることが必要
となる。しかし、高感度であるが故に重力加速度（１
Ｇ）程度の加速度によって可動電極１が天地方向Ｙの地
側（下方）へ変位しやすく（上記図４参照）、これが可
動電極１の変位のオフセットとなる。When detecting the acceleration in the vertical direction Y by controlling the vehicle suspension system, it is necessary to detect a relatively low acceleration due to the function of the system (eg, skyhook control). It is necessary to have sensitivity. However, due to the high sensitivity, the gravitational acceleration (1
The movable electrode 1 is easily displaced toward the ground side (downward) in the vertical direction Y by the acceleration of about G) (see FIG. 4), and this becomes an offset of the displacement of the movable electrode 1.
【００２１】そこで、本実施形態では、このオフセット
を抑制すべく、可動電極１と第１の固定電極２との間及
び可動電極１と第２の固定電極３との間の少なくとも一
方に静電引力を発生させるための電気信号を印加するこ
とにより、可動電極１における天地方向Ｙへの変位のオ
フセット分をキャンセルできるようにしている。Therefore, in the present embodiment, in order to suppress this offset, at least one of the static electricity is applied between the movable electrode 1 and the first fixed electrode 2 and between the movable electrode 1 and the second fixed electrode 3. By applying an electric signal for generating an attractive force, the offset of the displacement of the movable electrode 1 in the vertical direction Y can be canceled.
【００２２】例えば、図１に示す様に、可動電極１と天
側の第１の固定電極２との間に、重力加速度と同等の静
電引力ＦＥ（図中、白抜き矢印にて図示）を与えるよう
な定電圧源５を設ける（第１の例）。これにより、上記
検出用信号（第１、第２の搬送波）以外に、可動電極１
と第１の固定電極２との間に直流電圧Ｖが印加され、可
動電極１が第１の固定電極２側へ重力加速度による分だ
け変位するため、可動電極１のオフセット分をメカニカ
ルにキャンセルすることができる。For example, as shown in FIG. 1, between the movable electrode 1 and the first fixed electrode 2 on the top side, an electrostatic attractive force FE equivalent to the gravitational acceleration (shown by a white arrow in the figure) Is provided (first example). Thereby, in addition to the detection signal (first and second carrier waves), the movable electrode 1
DC voltage V is applied between the first fixed electrode 2 and the first fixed electrode 2, and the movable electrode 1 is displaced toward the first fixed electrode 2 by the gravitational acceleration, so that the offset of the movable electrode 1 is mechanically canceled. be able to.
【００２３】なお、上記第１の例では、電気信号により
発生する静電気力によって可動電極１の天地方向Ｙへの
オフセット分をキャンセル可能としているが、電気信号
が直流（０Ｈｚ）の電圧であるため、検出時に、電気信
号による静電気がノイズ等の誤差要因になることはな
い。In the first example, the offset of the movable electrode 1 in the vertical direction Y can be canceled by the electrostatic force generated by the electric signal. However, since the electric signal is a DC (0 Hz) voltage. At the time of detection, static electricity due to an electric signal does not become an error factor such as noise.
【００２４】また、図２、図３はオフセットキャンセル
用の電気信号の他の例（第２の例）、もう一つの他の例
（第３の例）を示すものであり、これら第２、第３の例
では、該電気信号を、印加加速度を検出するための周期
的に変化する検出信号としての第１の搬送波６ａ、第２
の搬送波６ｂと同期した信号としている。FIGS. 2 and 3 show another example (second example) of the electric signal for offset cancellation and another example (third example). In a third example, the electric signal is converted to a first carrier wave 6a as a periodically changing detection signal for detecting an applied acceleration,
Is synchronized with the carrier wave 6b.
【００２５】まず、図２に示す第２の例では、第１の搬
送波６ａとは極性を逆にした逆相の信号７を可動電極１
に対して印加することにより、可動電極１と第１の固定
電極２との間に重力加速度と同等の静電引力ＦＥを発生
させる。First, in the second example shown in FIG. 2, a signal 7 having a polarity opposite to that of the first carrier wave 6a is applied to the movable electrode 1.
, An electrostatic attraction FE equivalent to the gravitational acceleration is generated between the movable electrode 1 and the first fixed electrode 2.
【００２６】一方、図３に示す第３の例では、第１の搬
送波６ａの電位を、第２の搬送波６ｂよりも高くするこ
とで第１の搬送波６ａを電気信号８として用い、可動電
極１の電位（中点電位）と電気信号８とによって、可動
電極１と第１の固定電極２との間に重力加速度と同等の
静電引力ＦＥを発生させる。On the other hand, in the third example shown in FIG. 3, the potential of the first carrier 6a is set higher than that of the second carrier 6b so that the first carrier 6a is used as the electric signal 8 and the movable electrode 1 Of the movable electrode 1 and the first fixed electrode 2, an electrostatic attraction FE equivalent to the gravitational acceleration is generated by the electric potential (middle point potential) and the electric signal 8.
【００２７】これら第２、第３の例によっても、可動電
極１が第１の固定電極２側へ重力加速度による分だけ変
位するため、可動電極１の天地方向Ｙへのオフセット分
をキャンセルすることができる。また、第２、第３の例
においても、検出用信号６ａ、６ｂと電気信号７、８と
が同期しているため、基本的にノイズは発生しない。Also in these second and third examples, since the movable electrode 1 is displaced toward the first fixed electrode 2 by the gravitational acceleration, the offset of the movable electrode 1 in the vertical direction Y is canceled. Can be. Also in the second and third examples, since the detection signals 6a and 6b and the electric signals 7 and 8 are synchronized, basically no noise is generated.
【００２８】なお、上記各例では、可動電極１と第１の
固定電極２との間に静電引力ＦＥを発生させるように電
気信号を印加しているが、更に、可動電極１と第２の固
定電極３との間にも静電引力を発生させ、互いの静電引
力の釣り合いの結果、可動電極１が第１の固定電極２側
へ引っ張られるようにしても良い。In each of the above embodiments, an electric signal is applied between the movable electrode 1 and the first fixed electrode 2 so as to generate an electrostatic attraction FE. Also, the movable electrode 1 may be pulled toward the first fixed electrode 2 as a result of generating an electrostatic attractive force between the movable electrode 1 and the fixed electrode 3.
【００２９】以上、本実施形態によれば、可動電極１に
おける天地方向Ｙへの変位のオフセット分をキャンセル
するように、可動電極１と第１の固定電極２との間及び
可動電極１と第２の固定電極３との間の両方またはどち
らか一方に静電引力を発生させるための電気信号を印加
することができるため、可動電極１に発生する変位のオ
フセットを抑制し、検出精度を向上させることができ
る。As described above, according to the present embodiment, between the movable electrode 1 and the first fixed electrode 2 and between the movable electrode 1 and the first Since an electric signal for generating an electrostatic attractive force can be applied to both or one of the two fixed electrodes 3, the offset of the displacement generated in the movable electrode 1 is suppressed, and the detection accuracy is improved. Can be done.
【００３０】また、本発明は、天地方向（鉛直方向）の
加速度を検出する加速度センサ以外にも、天地方向以外
（例えば水平方向）の加速度を検出するものに適用して
も良い。これは、どのような容量式加速度センサにおい
ても、可動電極にオフセットを発生させるような外力が
加わる可能性は否定できないためであり、本発明を用い
れば、そのようなオフセット分をキャンセルできる。The present invention may be applied to a sensor for detecting acceleration in a direction other than the vertical direction (for example, in the horizontal direction), in addition to an acceleration sensor for detecting acceleration in the vertical direction (vertical direction). This is because it cannot be denied that any external force that causes an offset to be applied to the movable electrode can be denied in any capacitive acceleration sensor. With the present invention, such an offset can be canceled.
【図１】本発明の実施形態に係る容量式加速度センサの
模式的構成図である。FIG. 1 is a schematic configuration diagram of a capacitive acceleration sensor according to an embodiment of the present invention.
【図２】上記実施形態の他の例を示す図である。FIG. 2 is a diagram showing another example of the embodiment.
【図３】上記実施形態のもう１つの他の例を示す図であ
る。FIG. 3 is a diagram showing another example of the embodiment.
【図４】従来の一般的な容量式加速度センサの模式的構
成図である。FIG. 4 is a schematic configuration diagram of a conventional general capacitive acceleration sensor.
【図５】加速度と出力電圧との関係を示す模式図であ
る。FIG. 5 is a schematic diagram showing a relationship between acceleration and output voltage.
１…可動電極、２…第１の固定電極、３…第３の固定電
極。Reference numeral 1 represents a movable electrode, 2 represents a first fixed electrode, and 3 represents a third fixed electrode.
Claims (4)
と、 前記所定方向において前記可動電極に対し互いに反対側
にて対向して配置された第１及び第２の固定電極（２、
３）とを備え、 前記可動電極と前記第１の固定電極との間に第１の容量
が形成され、前記可動電極と前記第２の固定電極との間
に第２の容量が形成されており、 加速度が印加されたときに前記可動電極が前記所定方向
へ変位し、この可動電極の変位に伴う前記第１の容量及
び前記第２の容量の変化に基づいて印加加速度を検出す
るようにした容量式加速度センサにおいて、 前記可動電極と前記第１の固定電極との間及び前記可動
電極と前記第２の固定電極との間の少なくとも一方に静
電引力を発生させるための電気信号を印加することによ
り、前記可動電極における前記所定方向への変位のオフ
セット分をキャンセルできるようになっていることを特
徴とする容量式加速度センサ。A movable electrode (1) displaceable in a predetermined direction.
A first and a second fixed electrode (2, 2) arranged opposite to each other on the opposite side to the movable electrode in the predetermined direction.
3), wherein a first capacitance is formed between the movable electrode and the first fixed electrode, and a second capacitance is formed between the movable electrode and the second fixed electrode. The movable electrode is displaced in the predetermined direction when acceleration is applied, and the applied acceleration is detected based on a change in the first capacitance and the second capacitance caused by the displacement of the movable electrode. In the capacitive acceleration sensor, an electric signal for generating an electrostatic attraction is applied between at least one of the movable electrode and the first fixed electrode and between at least one of the movable electrode and the second fixed electrode. By doing so, the offset of the displacement in the predetermined direction in the movable electrode can be canceled.
前記第１の固定電極（２）との間、若しくは、前記可動
電極と前記第２の固定電極（３）との間に印加される直
流電圧であることを特徴とする請求項１に記載の容量式
加速度センサ。2. The electric signal is applied between the movable electrode (1) and the first fixed electrode (2) or between the movable electrode and the second fixed electrode (3). The capacitive acceleration sensor according to claim 1, wherein the DC voltage is a measured DC voltage.
に変化する検出用信号が前記可動電極と前記第１及び第
２の固定電極との間に印加されるようになっており、 前記電気信号は、前記検出用信号と同期した信号である
ことを特徴とする請求項１に記載の容量式加速度セン
サ。3. A periodically changing detection signal for detecting the applied acceleration is applied between the movable electrode and the first and second fixed electrodes. The capacitive acceleration sensor according to claim 1, wherein the signal is a signal synchronized with the detection signal.
あることを特徴とする請求項１ないし３のいずれか１つ
に記載の容量式加速度センサ。4. The capacitive acceleration sensor according to claim 1, wherein the predetermined direction is a direction along a vertical direction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000235983A JP2002048813A (en) | 2000-08-03 | 2000-08-03 | Capacitance-type acceleration sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000235983A JP2002048813A (en) | 2000-08-03 | 2000-08-03 | Capacitance-type acceleration sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2002048813A true JP2002048813A (en) | 2002-02-15 |
Family
ID=18728104
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000235983A Pending JP2002048813A (en) | 2000-08-03 | 2000-08-03 | Capacitance-type acceleration sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2002048813A (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2856475A1 (en) * | 2003-06-20 | 2004-12-24 | Commissariat Energie Atomique | CAPACITIVE MEASUREMENT SENSOR AND MEASUREMENT METHOD THEREOF |
| JP2005172836A (en) * | 2003-12-11 | 2005-06-30 | Robert Bosch Gmbh | Sensor having symmetric limitation of signal |
| JP2006017624A (en) * | 2004-07-02 | 2006-01-19 | Denso Corp | Angular velocity sensor |
| JP2009097932A (en) * | 2007-10-15 | 2009-05-07 | Freescale Semiconductor Inc | Capacitive detector |
| JP2010185721A (en) * | 2009-02-10 | 2010-08-26 | Asahi Kasei Electronics Co Ltd | Method and device for inspecting capacitance-type acceleration sensor |
| WO2011032080A3 (en) * | 2009-09-14 | 2011-07-21 | Schlumberger Canada Limited | Borehole force measurement |
| JP2012521006A (en) * | 2009-03-19 | 2012-09-10 | ヒューレット−パッカード デベロップメント カンパニー エル．ピー． | Three-phase capacity-based detection |
| JP2014238373A (en) * | 2013-06-10 | 2014-12-18 | 日本電波工業株式会社 | External force detection device |
| JP2016070815A (en) * | 2014-09-30 | 2016-05-09 | 株式会社日立製作所 | Acceleration sensor |
| CN113631890A (en) * | 2019-02-07 | 2021-11-09 | 德克萨斯仪器股份有限公司 | Compensating for mechanical tolerances in capacitive sensing control elements |
-
2000
- 2000-08-03 JP JP2000235983A patent/JP2002048813A/en active Pending
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004113931A2 (en) * | 2003-06-20 | 2004-12-29 | Commissariat A L'energie Atomique | Capacitive measuring sensor and associated measurement method |
| WO2004113931A3 (en) * | 2003-06-20 | 2005-04-07 | Commissariat Energie Atomique | Capacitive measuring sensor and associated measurement method |
| FR2856475A1 (en) * | 2003-06-20 | 2004-12-24 | Commissariat Energie Atomique | CAPACITIVE MEASUREMENT SENSOR AND MEASUREMENT METHOD THEREOF |
| JP2005172836A (en) * | 2003-12-11 | 2005-06-30 | Robert Bosch Gmbh | Sensor having symmetric limitation of signal |
| JP4556515B2 (en) * | 2004-07-02 | 2010-10-06 | 株式会社デンソー | Angular velocity sensor |
| JP2006017624A (en) * | 2004-07-02 | 2006-01-19 | Denso Corp | Angular velocity sensor |
| JP2009097932A (en) * | 2007-10-15 | 2009-05-07 | Freescale Semiconductor Inc | Capacitive detector |
| JP2010185721A (en) * | 2009-02-10 | 2010-08-26 | Asahi Kasei Electronics Co Ltd | Method and device for inspecting capacitance-type acceleration sensor |
| JP2012521006A (en) * | 2009-03-19 | 2012-09-10 | ヒューレット−パッカード デベロップメント カンパニー エル．ピー． | Three-phase capacity-based detection |
| US8661901B2 (en) | 2009-03-19 | 2014-03-04 | Hewlett-Packard Development Company, L.P. | Three phase capacitance-based sensing |
| WO2011032080A3 (en) * | 2009-09-14 | 2011-07-21 | Schlumberger Canada Limited | Borehole force measurement |
| US8485027B2 (en) | 2009-09-14 | 2013-07-16 | Schlumberger Technology Corporation | Borehole force measurement |
| JP2014238373A (en) * | 2013-06-10 | 2014-12-18 | 日本電波工業株式会社 | External force detection device |
| JP2016070815A (en) * | 2014-09-30 | 2016-05-09 | 株式会社日立製作所 | Acceleration sensor |
| CN113631890A (en) * | 2019-02-07 | 2021-11-09 | 德克萨斯仪器股份有限公司 | Compensating for mechanical tolerances in capacitive sensing control elements |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7316161B2 (en) | Rotation rate sensor | |
| JP4178658B2 (en) | Capacitive physical quantity detector | |
| US5495761A (en) | Integrated accelerometer with a sensitive axis parallel to the substrate | |
| US5616844A (en) | Capacitance type acceleration sensor | |
| US8393211B2 (en) | Sensor | |
| US7313958B2 (en) | Rotational rate sensor | |
| US8096180B2 (en) | Inertial sensor | |
| US6450029B1 (en) | Capacitive physical quantity detection device | |
| EP2336788B1 (en) | Inertial sensor | |
| JP2010127763A (en) | Semiconductor mechanical quantity detection sensor and controller using the same | |
| JPH05142249A (en) | Three dimensional acceleration sensor | |
| US6508126B2 (en) | Dynamic quantity sensor having movable and fixed electrodes with high rigidity | |
| US6761070B2 (en) | Microfabricated linear accelerometer | |
| JP2002048813A (en) | Capacitance-type acceleration sensor | |
| US20040187573A1 (en) | Semiconductor dynamic quantity sensor | |
| US8915137B2 (en) | Yaw rate sensor, yaw rate sensor system, and method for operating a yaw rate sensor | |
| JP2005227143A (en) | Method for inspecting semiconductor dynamic quantity sensor | |
| JP2003248016A (en) | Capacitance-type accelerometer | |
| JP2012242201A (en) | Capacity type physical quantity detector | |
| JP3282360B2 (en) | Capacitive sensor | |
| JP5369819B2 (en) | Capacitive physical quantity detector | |
| JPH03293565A (en) | Pwm electrostatic servo type accelerometer | |
| JPH05264577A (en) | Acceleration sensor, air bag apparatus and body controller using the same | |
| JP2002299640A (en) | Dynamical amount sensor | |
| JP3462225B2 (en) | Semiconductor yaw rate sensor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20060830 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20080808 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20080916 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20090127 |