JPH0727808A - Noncontact type surface potentiometer - Google Patents
Noncontact type surface potentiometerInfo
- Publication number
- JPH0727808A JPH0727808A JP17304093A JP17304093A JPH0727808A JP H0727808 A JPH0727808 A JP H0727808A JP 17304093 A JP17304093 A JP 17304093A JP 17304093 A JP17304093 A JP 17304093A JP H0727808 A JPH0727808 A JP H0727808A
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- Japan
- Prior art keywords
- sensor element
- sample
- detected
- detection electrode
- surface potential
- Prior art date
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- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
- Other Investigation Or Analysis Of Materials By Electrical Means (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、ＰＰＣ(plain paper
copier)、ＦＡＸ(facsimile) 等に使用されている感光
体などの表面電位を非接触で測定する非接触型表面電位
計に関するものである。BACKGROUND OF THE INVENTION The present invention relates to PPC (plain paper).
The present invention relates to a non-contact type surface electrometer for measuring the surface potential of a photoconductor used for copier), FAX (facsimile), etc. in a non-contact manner.
【０００２】[0002]
【従来の技術】図７は非接触で表面電位の測定を行う従
来の表面電位計の測定原理を示す構成図である。同図に
おいて、１は複写機の感光体などの被検出試料で、電源
２により＋（正）に帯電されている。2. Description of the Related Art FIG. 7 is a block diagram showing the measurement principle of a conventional surface potential meter which measures the surface potential in a non-contact manner. In the figure, 1 is a sample to be detected such as a photoconductor of a copying machine, which is charged to + (positive) by a power source 2.
【０００３】３はセンサ部のケースで、測定用の小窓４
が設けられており、この小窓４の内側に一対の音叉型の
振動子５が配設されている。６は小窓４の内側に配設さ
れた検出電極である。Reference numeral 3 is a case of the sensor section, which is a small window 4 for measurement.
Is provided, and a pair of tuning fork type vibrators 5 are arranged inside the small window 4. Reference numeral 6 is a detection electrode arranged inside the small window 4.
【０００４】図８は上記センサ部の構造を模式的に示し
たものである。一対の振動子５は、圧電素子（圧電セラ
ミックス）７が接着された音叉８に一体的に構成されて
おり、圧電素子７には駆動回路９から交流電圧が印加さ
れるようになっている。また、検出電極６の出力はプリ
アンプ１０により増幅され、不図示の信号処理回路に入
力されるように構成されている。FIG. 8 schematically shows the structure of the sensor section. The pair of vibrators 5 are integrally formed with a tuning fork 8 to which a piezoelectric element (piezoelectric ceramics) 7 is adhered, and an alternating voltage is applied to the piezoelectric element 7 from a drive circuit 9. The output of the detection electrode 6 is amplified by the preamplifier 10 and input to a signal processing circuit (not shown).
【０００５】上記のような表面電位計において、被検出
試料１の表面電位を測定しようとする場合は、ケース３
の小窓４を被検出試料１の表面に向けてセットする。こ
の時、コロナ放電等により被検出試料１の表面に電荷が
あると、その表面より図７の破線で示すような電気力線
Ａが検出電極６に向けて出ている。この電気力線Ａは、
ケース３の小窓４を通して検出電極６に達しているが、
ここで被検出試料１と検出電極６との間の距離を一定値
に固定しておき、電気力線Ａを何らかの方法でチョッパ
し、面積Ｓの検出電極６に到達する電気力線Ａの時間的
変化量を上記信号処理回路に組み込まれたＦＥＴのゲー
トに入力して検出することにより、被検出試料１の表面
電位を知ることができる。In the case of measuring the surface potential of the sample 1 to be detected in the surface electrometer as described above, Case 3 is used.
The small window 4 is set toward the surface of the sample to be detected 1. At this time, if there is electric charge on the surface of the sample 1 to be detected due to corona discharge or the like, electric lines of force A as shown by the broken line in FIG. This line of electric force A is
Although it reaches the detection electrode 6 through the small window 4 of the case 3,
Here, the distance between the sample to be detected 1 and the detection electrode 6 is fixed to a constant value, the electric force line A is choppered by some method, and the time of the electric force line A reaching the detection electrode 6 having the area S is determined. The surface potential of the sample to be detected 1 can be known by inputting the amount of dynamic change into the gate of the FET incorporated in the signal processing circuit and detecting the amount.
【０００６】すなわち、上記電気力線Ａのチョッパの一
つの方式として、図７の例では交流方式を用いており、
安定した振動数をもつ音叉８に圧電素子７を貼り付け、
この圧電素子７に交流電圧を印加して振動子５を矢印Ｂ
方向に振動させ、これにより電気力線Ａをチョッピング
している。この時、静電場における上記被検出試料１と
検出電極６を誘電率εa の空気層が入った電極間隔ｒの
平板コンデンサと見做すと、このコンデンサの静電容量
Ｃと電荷Ｑは、印加電圧（被検出試料１の電位）をＶと
すると、Ｃ＝εa Ｓ／ｒ、Ｑ＝ＣＶとなる。That is, as one method of the chopper of the electric flux line A, the AC method is used in the example of FIG.
Attach the piezoelectric element 7 to the tuning fork 8 with stable frequency,
AC voltage is applied to the piezoelectric element 7 to move the vibrator 5 to the arrow B
In this way, the lines of electric force A are chopped. At this time, when the sample 1 to be detected and the detection electrode 6 in the electrostatic field are regarded as a flat plate capacitor with an electrode space r containing an air layer having a dielectric constant ε a , the electrostatic capacitance C and the charge Q of this capacitor are When the applied voltage (potential of the sample to be detected 1) is V, C = ε a S / r and Q = CV.
【０００７】上式の関係から、電気力線Ａのチョッピン
グによるコンデンサの漏れ電流Ｉの変化を求め、これを
交流信号電圧として検出する。この電流Ｉは、From the relation of the above equation, the change in the leakage current I of the capacitor due to the chopping of the electric force line A is obtained, and this is detected as the AC signal voltage. This current I is
【０００８】[0008]
【数１】 [Equation 1]
【０００９】で表される。この時、Ｃ＝一定とすると、It is represented by At this time, if C = constant,
【００１０】[0010]
【数２】 [Equation 2]
【００１１】となる。そして、これを交流信号電圧とし
てプリアンプ１０により増幅し、被検出試料１の表面電
位を相対的に求めている。[0011] Then, this is amplified as an AC signal voltage by the preamplifier 10 to relatively determine the surface potential of the sample 1 to be detected.
【００１２】[0012]
【発明が解決しようとする課題】しかしながら、上記の
ような従来の非接触型表面電位計にあっては、電気力線
の通る小窓に対して検出電極の位置やチョッパ位置がず
れると、出力レベルが所定値より変化し、正確な表面電
位の測定ができないという問題点があった。However, in the above-mentioned conventional non-contact type surface electrometer, when the position of the detection electrode or the position of the chopper deviates from the small window through which the lines of electric force pass, the output is generated. There is a problem in that the level changes from a predetermined value and the surface potential cannot be measured accurately.
【００１３】また、小窓を有しているため、実際に機械
に組み込んで使用する際、例えばトナーなどがケース内
に入って圧電式の音叉に悪影響を及ぼし、リークの発生
や感度低下を招くなどの問題点があった。Further, since it has a small window, when it is actually incorporated into a machine for use, for example, toner or the like enters the case and adversely affects the piezoelectric tuning fork, resulting in leakage or deterioration of sensitivity. There were problems such as.
【００１４】この発明は、上記のような問題点に着目し
てなされたもので、正確な表面電位の測定ができ、また
防塵構造が可能で、トナー等によるリークの発生を防止
することができ、且つセンサプローブの小型化を図るこ
とができるとともに、センサプローブのクリーニングが
容易な非接触型表面電位計を提供することを目的として
いる。The present invention has been made by paying attention to the above-mentioned problems. It is possible to accurately measure the surface potential, a dustproof structure is possible, and it is possible to prevent the occurrence of leakage due to toner or the like. In addition, it is an object of the present invention to provide a non-contact type surface electrometer which can reduce the size of the sensor probe and can easily clean the sensor probe.
【００１５】[0015]
【課題を解決するための手段】この発明の非接触型表面
電位計は、印加電圧に応じて光の屈折率が変化するポッ
ケルス結晶を用いたセンサ素子と、被検出試料の表面に
対向して配置され、前記センサ素子の両側の電極の一方
と電気的に接続された検知電極と、前記センサ素子のポ
ッケルス結晶を通過した光の強度から前記被検出試料の
表面電位を検出する信号処理部とから構成したものであ
る。The non-contact surface electrometer of the present invention comprises a sensor element using a Pockels crystal in which the refractive index of light changes according to an applied voltage, and a sensor element facing the surface of a sample to be detected. A detection electrode that is arranged and electrically connected to one of the electrodes on both sides of the sensor element, and a signal processing unit that detects the surface potential of the sample to be detected from the intensity of light that has passed through the Pockels crystal of the sensor element. It is composed of.
【００１６】また、上記センサ素子の検知電極と接続さ
れた電極の面積より検知電極の面積の方が大きく、且つ
比例関係を有するように構成したものである。Further, the area of the sensing electrode is larger than the area of the electrode connected to the sensing electrode of the above-mentioned sensor element, and has a proportional relationship.
【００１７】[0017]
【作用】この発明の非接触型表面電位計においては、光
学式のセンサが使用されているので、機械的な位置関係
の影響を受けることなく測定でき、また防塵構造とする
ことができる。In the non-contact type surface electrometer of the present invention, since the optical sensor is used, the measurement can be performed without being affected by the mechanical positional relationship, and the dustproof structure can be obtained.
【００１８】また、検知電極のみのセンサプローブと他
の部分とを分けることができるので、センサプローブの
小型化を図ることができ、センサプローブのクリーニン
グも容易である。Further, since the sensor probe having only the detection electrode and the other portion can be separated, the sensor probe can be downsized and the sensor probe can be easily cleaned.
【００１９】[0019]
【実施例】図１はこの発明の一実施例による非接触型表
面電位計の概略構成を示す図である。図において、１は
表面電位を測定すべき被検出試料、１１は印加電圧に応
じて光の屈曲率が変化するポッケルス(Pockels) 結晶を
用いたセンサ素子で、両側に電極１２ａ，１２ｂが平行
に設けられている。1 is a diagram showing a schematic configuration of a non-contact type surface electrometer according to an embodiment of the present invention. In the figure, 1 is a sample to be measured whose surface potential is to be measured, 11 is a sensor element using a Pockels crystal in which the bending ratio of light changes according to an applied voltage, and electrodes 12a and 12b are arranged in parallel on both sides. It is provided.
【００２０】１３は被検出試料１の表面に対向して配置
される検知電極で、センサ素子１１の両側の電極１２
ａ，１２ｂの一方の電極１２ａとリード線１４により電
気的に接続されており、センサ素子１１の他方の電極１
２ｂは接地されている。１５はセンサ素子１１内のポッ
ケルス結晶を通過した光の強度から被検出試料１の表面
電位を検出する信号処理部である。Reference numeral 13 denotes a detection electrode which is arranged so as to face the surface of the sample to be detected 1 and which is located on both sides of the sensor element 11.
a and 12b, which are electrically connected to one electrode 12a of the sensor element 11 by the lead wire 14, and the other electrode 1 of the sensor element 11
2b is grounded. A signal processing unit 15 detects the surface potential of the sample 1 to be detected from the intensity of light that has passed through the Pockels crystal in the sensor element 11.
【００２１】上記検知電極１３は、例えば銅，真鍮，ア
ルミニウム等の金属板で形成され、その端部に上記リー
ド線１４が接続されている。そして、この検知電極１３
が被検出試料１と平行に距離ｒ１をもって配置され、被
検出試料１の表面電位に応じた電圧がこの検知電極１３
を介してセンサ素子１１に印加され、その印加電圧に応
じてセンサ素子１１内を通過した出射光の強度が変化す
る。したがって、この出射光の強度より被検出試料１の
表面電位を信号処理部１５にて求めることができる。The detection electrode 13 is formed of, for example, a metal plate of copper, brass, aluminum or the like, and the lead wire 14 is connected to the end portion thereof. And this detection electrode 13
Are arranged in parallel with the sample to be detected 1 with a distance r1, and a voltage corresponding to the surface potential of the sample to be detected 1 is detected by the detection electrode 13.
The intensity of the emitted light that has been applied to the sensor element 11 through the sensor element 11 and has passed through the sensor element 11 changes according to the applied voltage. Therefore, the signal processing unit 15 can obtain the surface potential of the sample to be detected 1 from the intensity of the emitted light.
【００２２】図２は上述の非接触型表面電位計の測定原
理を示す構成図である。被検出試料１は、電源２により
正または負（ここでは正とする）に帯電されている。ま
たセンサ素子１１は、上述のように印加電圧（被検出試
料１の表面電位）に応じて光の屈曲率（透過率）が変化
する。このセンサ素子１１は、等方性光弾性結晶特に単
軸晶系のＬｉＴａＯ3 ，ＬｉＮｂＯ3 等のポッケルス(P
ockels) 結晶と偏光子，波長板，検光子で構成されてお
り、電圧が印加されると、その印加電圧に応じて光の屈
曲率が線形的に変化し、これを通過した出射光の強度が
印加電圧に依存する性質を有している。FIG. 2 is a block diagram showing the measuring principle of the above-mentioned non-contact type surface electrometer. The sample 1 to be detected is charged positively or negatively (here, positive) by the power supply 2. Further, in the sensor element 11, the bending ratio (transmittance) of light changes according to the applied voltage (surface potential of the sample 1 to be detected) as described above. This sensor element 11 is composed of isotropic photoelastic crystal, especially uniaxial crystal system LiTaO 3 , LiNbO 3 or other Pockels (P
ockels) It consists of a crystal, a polarizer, a wave plate, and an analyzer. When a voltage is applied, the bending ratio of the light changes linearly according to the applied voltage, and the intensity of the emitted light that passes through it. Has the property of depending on the applied voltage.
【００２３】また、図２中、１６はセンサ素子１１の内
部を通過した光を受光するフォトダイオード（ＰＤ）を
有した受光部、１７は受光部１６の出力を増幅するアン
プで、増幅された信号は信号処理回路（演算部を含む）
１８に入力され、この信号処理回路１８にてセンサ素子
１１からの光の強度から被検出試料１の表面電位が検出
される。Further, in FIG. 2, 16 is a light receiving portion having a photodiode (PD) for receiving the light passing through the inside of the sensor element 11, and 17 is an amplifier for amplifying the output of the light receiving portion 16. Signals are signal processing circuits (including arithmetic unit)
The signal is input to 18, and the signal processing circuit 18 detects the surface potential of the sample 1 to be detected from the intensity of light from the sensor element 11.
【００２４】図３は図２の表面電位計による測定動作を
示す図である。センサ素子１１と被検出試料１との位置
関係は図３の（ａ）に示すようになっており、センサ素
子１１を電界中に置き、その端面より偏光子を通して光
を入射させ、出射光の強度を測定する。FIG. 3 is a diagram showing a measuring operation by the surface electrometer of FIG. The positional relationship between the sensor element 11 and the sample to be detected 1 is as shown in FIG. 3 (a). The sensor element 11 is placed in an electric field, light is made incident through the polarizer from its end face, and the emitted light Measure the strength.
【００２５】この時、入射光はまず偏光子を通して直線
偏光に変換され、センサ素子１１内の長さＬの結晶の内
部を通過して楕円偏光に変換される。図３の（ｂ）はそ
の様子を示したものであり、Ｘ−Ｚ面に例えば４５°の
波長入の直線偏波光を入射させると、この直線偏波光が
Ｘ方向とＹ方向の屈曲率ｎX ，ｎy の違いにより上記結
晶内部を通過する際、楕円偏光に変換される。At this time, the incident light is first converted into linearly polarized light through the polarizer, passes through the inside of the crystal having the length L in the sensor element 11, and is converted into elliptically polarized light. FIG. 3B shows such a state. When linearly polarized light having a wavelength of 45 ° is incident on the XZ plane, the linearly polarized light is bent in the X-direction and the Y-direction at a bending ratio n. When passing through the inside of the crystal due to the difference between X and ny , it is converted into elliptically polarized light.
【００２６】ここで、図３の（ａ）のようにセンサ素子
１１を直接電界中に置いた場合、被検出試料１の表面が
帯電された時に、静電容量によりセンサ素子１１の両端
に電位差が生じる。この時の等価回路を図４の（ａ）に
示す。そして、被検出試料１とセンサ素子１１との間の
空気層のコンデンサ容量をＣ１、センサ素子１１のコン
デンサ容量をＣ２とすれば、これらの直列つなぎと見な
すことができ、図４の（ｂ）に示す各々の電位差Ｖ１と
Ｖ２の関係は、被検出試料１とセンサ素子１１の反対側
の電極面との間の距離をｒ、結晶の厚さをｄとすると、Here, when the sensor element 11 is directly placed in an electric field as shown in FIG. 3A, when the surface of the sample 1 to be detected is charged, a potential difference is generated across the sensor element 11 due to electrostatic capacitance. Occurs. The equivalent circuit at this time is shown in FIG. If the capacitor capacity of the air layer between the sample to be detected 1 and the sensor element 11 is C1 and the capacitor capacity of the sensor element 11 is C2, these can be regarded as a series connection, and FIG. The relationship between the respective potential differences V1 and V2 shown in FIG. 3 is that when the distance between the sample to be detected 1 and the electrode surface on the opposite side of the sensor element 11 is r and the thickness of the crystal is d,
【００２７】[0027]
【数３】 [Equation 3]
【００２８】にて表わすことができる。Can be represented by
【００２９】すなわち、上記被検出試料１と電極１２ｂ
との間の距離ｒを一定として、被検出試料１の表面電位
が変化すると、電極１２ａ，１２ｂ間の電位も変化し、
この電位の大きさに応じて光が光路長Ｌのセンサ素子１
１の内部を通過した時の出射光の強度が変化する。した
がって、このセンサ素子１１の出射光の強度を検出し、
その検出電圧を求めれば、上記ｒ，Ｌの値がわかってい
るので、被検出試料１の表面電位を知ることができる。That is, the sample to be detected 1 and the electrode 12b
When the surface potential of the sample 1 to be detected changes while the distance r between the electrodes is constant, the potential between the electrodes 12a and 12b also changes,
According to the magnitude of this potential, the sensor element 1 whose light has an optical path length L
The intensity of the emitted light when passing through the inside of 1 changes. Therefore, by detecting the intensity of the light emitted from the sensor element 11,
If the detected voltage is obtained, the values of r and L are known, so that the surface potential of the sample 1 to be detected can be known.
【００３０】以上、光学式の表面電位計の測定原理につ
いて説明したが、本実施例では図１に示すように、新た
に検知電極１３を設けており、且つ図３の（ａ）の場合
と電位差が同じ効果を持つようにしている。The measurement principle of the optical surface electrometer has been described above. However, in this embodiment, as shown in FIG. 1, a detection electrode 13 is newly provided, and in addition to the case of FIG. The potential difference has the same effect.
【００３１】すなわち、上記検知電極１３を被検出試料
１に対向して配置した時、被検出試料１の表面電位によ
ってセンサ素子１１の両端に電位差が生じる。この電位
差は、検知電極１３の表面積に依存し、被検出試料１か
ら出る電気力線の受ける量によって決まる。That is, when the detection electrode 13 is arranged so as to face the sample 1 to be detected, a potential difference is generated across the sensor element 11 due to the surface potential of the sample 1 to be detected. This potential difference depends on the surface area of the detection electrode 13 and is determined by the amount of electric force lines emitted from the sample 1 to be detected.
【００３２】そして、検知電極１３の接続されたセンサ
素子１１の電極１２ａの表面積Ｓ１と検知電極１３の面
積Ｓ２との間には相関関係があり、面積Ｓ１より面積Ｓ
２の方が大きく、且つ比例関係を有している。There is a correlation between the surface area S1 of the electrode 12a of the sensor element 11 connected to the detection electrode 13 and the area S2 of the detection electrode 13, and the area S1 is larger than the area S1.
2 is larger and has a proportional relationship.
【００３３】例えば、ＬｉＴａＯ3 の結晶で厚さｔ＝
０．５mmのセンサ素子１１の電極１２ａの面積Ｓ１＝１
１２mm2 、電極間距離ｒ１＝０．５mm、印加電圧Ｖ＝３
００Ｖの条件下にて、検知電極１３の面積Ｓ２とセンサ
素子１１の印加電圧Ｖ２との関係は表１のようになる。For example, a crystal of LiTaO 3 has a thickness t =
Area S1 = 1 of the electrode 12a of the sensor element 11 of 0.5 mm
12 mm 2 , inter-electrode distance r1 = 0.5 mm, applied voltage V = 3
Table 1 shows the relationship between the area S2 of the detection electrode 13 and the applied voltage V2 of the sensor element 11 under the condition of 00V.
【００３４】[0034]
【表１】 [Table 1]
【００３５】このような構成とすることにより、図５に
示すように、検知電極１３のみのセンサプローブ１９
と、光学系（センサ素子１１）及び信号処理部１５から
なる本体２０とに分離し、それらをリード線１４によっ
て結線した光学式の表面電位計を実現することができ
る。With this structure, as shown in FIG. 5, the sensor probe 19 having only the detection electrode 13 is provided.
It is possible to realize an optical surface electrometer which is separated into a main body 20 including an optical system (sensor element 11) and a signal processing unit 15 and connected by a lead wire 14.
【００３６】このため、従来のように機械的な位置のず
れによる影響はなく、簡単に正確な表面電位の測定がで
き、また防塵構造が可能で、トナー等によるリークの発
生を防止することができる。Therefore, there is no influence of mechanical displacement as in the conventional case, the surface potential can be easily and accurately measured, a dustproof structure is possible, and leakage due to toner or the like can be prevented. it can.
【００３７】また、上記のように検知電極１３のみのセ
ンサプローブ１９と他の光学系及び信号処理系を含む本
体２０とに分離できるので、被検出試料１の表面近くに
センサプローブ１９を近づけることが可能であり、セン
サプローブ１９の小型化を図ることができるとともに、
センサプローブ１９のクリーニングが容易である。Since the sensor probe 19 having only the detection electrode 13 and the main body 20 including other optical system and signal processing system can be separated as described above, the sensor probe 19 should be brought close to the surface of the sample 1 to be detected. It is possible to reduce the size of the sensor probe 19, and
Cleaning of the sensor probe 19 is easy.
【００３８】図６は上記センサプローブ１９の一例を示
す外観図である。このセンサプローブ１９は、樹脂枠２
１に検知電極１３が嵌め込まれた構成となっており、検
知電極１３の一端とリード線１４とが接続されている。
また、樹脂枠２１には、取り付け時の固定用のビス止め
穴２２が設けられている。FIG. 6 is an external view showing an example of the sensor probe 19. This sensor probe 19 has a resin frame 2
1 has a configuration in which the detection electrode 13 is fitted, and one end of the detection electrode 13 and the lead wire 14 are connected.
Further, the resin frame 21 is provided with a screw fixing hole 22 for fixing at the time of mounting.
【００３９】[0039]
【発明の効果】以上のように、この発明によれば、光学
式のセンサ素子を使用し、また検知電極を設けて、これ
とセンサ素子を接続した構成としたため、機械的な位置
のずれによる影響はなく、簡単に正確な表面電位の測定
ができ、また防塵構造とすることができるという効果が
ある。As described above, according to the present invention, the optical sensor element is used, and the detection electrode is provided and the sensor element is connected to the detection electrode. There is no effect, and the surface potential can be measured easily and accurately, and a dustproof structure can be obtained.
【００４０】また、検知電極のみのセンサプローブと他
の光学系及び信号処理系を含む本体とに分離できるの
で、センサプローブの小型化を図ることができるととも
に、センサプローブのクリーニングが容易になるという
効果がある。Further, since the sensor probe having only the detection electrode and the main body including the other optical system and the signal processing system can be separated, the sensor probe can be downsized and the sensor probe can be easily cleaned. effective.
【図１】 この発明の一実施例を示す概略構成図FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.
【図２】 図１の電位計の測定原理を示す構成図FIG. 2 is a block diagram showing the measurement principle of the electrometer of FIG.
【図３】 図２の電位計の測定動作を示す説明図FIG. 3 is an explanatory diagram showing a measurement operation of the electrometer of FIG.
【図４】 図３のセンサ素子の等価回路図FIG. 4 is an equivalent circuit diagram of the sensor element of FIG.
【図５】 図１の電位計の全体構成を示すブロック図5 is a block diagram showing the overall configuration of the electrometer of FIG.
【図６】 図５のセンサプローブの一例を示す外観図6 is an external view showing an example of the sensor probe of FIG.
【図７】 従来例を示す構成図FIG. 7 is a configuration diagram showing a conventional example.
【図８】 図７のセンサ部の構造を示す斜視図8 is a perspective view showing the structure of the sensor unit of FIG.
１ 被検出試料 １１ センサ素子 １２ａ，１２ｂ 電極 １３ 検知電極 １４ リード線 １５ 信号処理部 １９ センサプローブ ２０ 本体 DESCRIPTION OF SYMBOLS 1 Detected sample 11 Sensor element 12a, 12b Electrode 13 Detection electrode 14 Lead wire 15 Signal processing part 19 Sensor probe 20 Main body
─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成６年４月７日[Submission date] April 7, 1994
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】請求項２[Name of item to be corrected] Claim 2
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【手続補正２】[Procedure Amendment 2]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００１６[Correction target item name] 0016
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００１６】また、上記センサ素子の電極の面積より検
知電極の面積の方が大きく、且つ比例関係を有するよう
に構成したものである。Furthermore, it is large area of area than the detection electrode of the electrodes of the sensor element, which is constituted and to have a proportional relationship.
【手続補正３】[Procedure 3]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００１９[Correction target item name] 0019
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００１９】[0019]
【実施例】図１はこの発明の一実施例による非接触型表
面電位計の概略構成を示す図である。図において、１は
表面電位を測定すべき被検出試料、１１は印加電圧に応
じて光の屈折率が変化するポッケルス（Ｐｏｃｋｅｌ
ｓ）結晶を用いたセンサ素子で、両側に電極１２ａ，１
２ｂが平行に設けられている。1 is a diagram showing a schematic configuration of a non-contact type surface electrometer according to an embodiment of the present invention. In the figure, 1 is the detected sample to be measured the surface potential, 11 refraction index of the light changes depending on the voltage applied Pockels (Pockel
s) A sensor element using a crystal, electrodes 12a, 1 on both sides
2b are provided in parallel.
【手続補正４】[Procedure amendment 4]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００２２[Name of item to be corrected] 0022
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００２２】図２は上述の非接触型表面電位計の測定原
理を示す構成図である。被検出試料１は、電源２により
正または負（ここでは正とする）に帯電されている。ま
たセンサ素子１１は、上述のように印加電圧（被検出試
料１の表面電位）に応じて光の屈折率（透過率）が変化
する。このセンサ素子１１は、三方晶系の単軸結晶Ｌｉ
ＴａＯ3，ＬｉＮｂＯ3等のポッケルス（Ｐｏｃｋｅｌ
ｓ）結晶と偏光子，波長板，検光子で構成されており、
電圧が印加されると、その印加電圧に応じて光の屈折率
が線形的に変化し、これを通過した出射光の強度が印加
電圧に依存する性質を有している。FIG. 2 is a block diagram showing the measuring principle of the above-mentioned non-contact type surface electrometer. The sample 1 to be detected is charged positively or negatively (here, positive) by the power supply 2. The sensor element 11, refraction of the light (transmittance) changes depending on the voltage applied as described above (the surface potential of the detection sample 1). The sensor element 11 is a trigonal uniaxial crystal Li.
Pockels such as TaO 3 and LiNbO 3
s) It consists of a crystal, a polarizer, a wave plate, and an analyzer.
When a voltage is applied, it has a property of light refraction index of the in accordance with the applied voltage linearly changes, the intensity of outgoing light that has passed through it depends on the applied voltage.
【手続補正５】[Procedure Amendment 5]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００２５[Name of item to be corrected] 0025
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００２５】この時、入射光はまず偏光子を通して直線
偏光に変換され、センサ素子１１内の長さＬの結晶の内
部を通過して楕円偏光に変換される。図３の（ｂ）はそ
の様子を示したものであり、Ｘ−Ｚ面に例えば４５°の
波長入の直線偏波光を入射させると、この直線偏波光が
Ｘ方向とＺ方向の屈折率ｎX ，ｎ Z の違いにより上記結
晶内部を通過する際、楕円偏光に変換される。At this time, the incident light is first converted into linearly polarized light through the polarizer, passes through the inside of the crystal having the length L in the sensor element 11, and is converted into elliptically polarized light. Figure. 3 (b) is limited to showing its state, when the incident linearly polarized light of wavelength incident in the X-Z plane for example 45 °, refraction index the linearly polarized light in the X direction and the Z-direction When passing through the inside of the crystal due to the difference between n X and n Z , it is converted into elliptically polarized light.
【手続補正６】[Procedure correction 6]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００２６[Correction target item name] 0026
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００２６】ここで、図３の（ａ）のようにセンサ素子
１１を直接電界中に置いた場合、被検出試料１の表面が
帯電された時に、静電誘導によりセンサ素子１１の両端
に電位差が生じる。この時の等価回路を図４の（ａ）に
示す。そして、被検出試料１とセンサ素子１１との間の
空気層のコンデンサ容量をＣ１、センサ素子１１のコン
デンサ容量をＣ２とすれば、これらの直列つなぎと見な
すことができ、図４の（ｂ）に示す各々の電位差Ｖ１と
Ｖ２の関係は、被検出試料１とセンサ素子１１の反対側
の電極面との間の距離をｒ、結晶の厚さをｄ、ポッケル
ス素子の比誘電率をεとすると、Here, when the sensor element 11 is directly placed in an electric field as shown in FIG. 3A, when the surface of the sample 1 to be detected is charged, electrostatic induction induces a potential difference across the sensor element 11. Occurs. The equivalent circuit at this time is shown in FIG. If the capacitor capacity of the air layer between the sample to be detected 1 and the sensor element 11 is C1 and the capacitor capacity of the sensor element 11 is C2, these can be regarded as a series connection, and FIG. The relationship between the potential differences V1 and V2 shown in Fig. 4 is that the distance between the sample to be detected 1 and the electrode surface on the opposite side of the sensor element 11 is r, the thickness of the crystal is d 2 , and the Pockel
If the relative permittivity of the element is ε ,
【手続補正７】[Procedure Amendment 7]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００２７[Name of item to be corrected] 0027
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００２７】[0027]
【数３】 [Equation 3]
【手続補正８】[Procedure Amendment 8]
【補正対象書類名】図面[Document name to be corrected] Drawing
【補正対象項目名】図３[Name of item to be corrected] Figure 3
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【図３】 [Figure 3]
Claims (2)
ポッケルス結晶を用いたセンサ素子と、被検出試料の表
面に対向して配置され、前記センサ素子の両側の電極の
一方と電気的に接続された検知電極と、前記センサ素子
のポッケルス結晶を通過した光の強度から前記被検出試
料の表面電位を検出する信号処理部とからなる非接触型
表面電位計。1. A sensor element using a Pockels crystal in which the refractive index of light changes according to an applied voltage, and one of electrodes on both sides of the sensor element, which is arranged so as to face the surface of a sample to be detected, is electrically connected to the sensor element. A non-contact type surface electrometer comprising a detection electrode connected to the sensor element and a signal processing unit for detecting the surface potential of the sample to be detected from the intensity of light passing through the Pockels crystal of the sensor element.
の面積より検知電極の面積の方が大きく、且つ比例関係
を有していることを特徴とする請求項１記載の非接触型
表面電位計。2. The non-contact type surface potential according to claim 1, wherein the area of the sensing electrode is larger than the area of the electrode connected to the sensing electrode of the sensor element and has a proportional relationship. Total.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17304093A JPH0727808A (en) | 1993-07-13 | 1993-07-13 | Noncontact type surface potentiometer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17304093A JPH0727808A (en) | 1993-07-13 | 1993-07-13 | Noncontact type surface potentiometer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0727808A true JPH0727808A (en) | 1995-01-31 |
Family
ID=15953095
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17304093A Pending JPH0727808A (en) | 1993-07-13 | 1993-07-13 | Noncontact type surface potentiometer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0727808A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0194270A (en) * | 1987-10-06 | 1989-04-12 | Murata Mfg Co Ltd | Surface potential detector |
-
1993
- 1993-07-13 JP JP17304093A patent/JPH0727808A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0194270A (en) * | 1987-10-06 | 1989-04-12 | Murata Mfg Co Ltd | Surface potential detector |
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