JP3096162B2 - Surface electrometer - Google Patents

Surface electrometer

Info

Publication number
JP3096162B2
JP3096162B2 JP04204704A JP20470492A JP3096162B2 JP 3096162 B2 JP3096162 B2 JP 3096162B2 JP 04204704 A JP04204704 A JP 04204704A JP 20470492 A JP20470492 A JP 20470492A JP 3096162 B2 JP3096162 B2 JP 3096162B2
Authority
JP
Japan
Prior art keywords
electrode
pitch
shield case
blade
window
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.)
Expired - Fee Related
Application number
JP04204704A
Other languages
Japanese (ja)
Other versions
JPH0651006A (en
Inventor
利幸 関谷
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Canon Inc
Original Assignee
Canon Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Canon Inc filed Critical Canon Inc
Priority to JP04204704A priority Critical patent/JP3096162B2/en
Publication of JPH0651006A publication Critical patent/JPH0651006A/en
Application granted granted Critical
Publication of JP3096162B2 publication Critical patent/JP3096162B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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  • Photoreceptors In Electrophotography (AREA)
  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【産業上の利用分野】この発明は表面電位計、特に電子
写真方式の複写装置,プリンタ等で用いられる表面電位
計に関するものである。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface voltmeter, and more particularly to a surface voltmeter used in an electrophotographic copying machine, a printer and the like.

【0002】[0002]

【従来の技術】従来、電子写真方式の複写装置では、画
像形成プロセスにおいて感光体ドラムに対し、まず感光
体表面に一様な静帯電(1次帯電)をおこさせる一方、
それに対し原稿の反射光をあて、この静帯電に対する明
度に応じた放電をおこさせ、静電潜像をドラム上に形成
する。従って、より画像品位を向上させるためにはこの
1次帯電を所定の値に制御することが不可欠となり、表
面電位計を使用し、表面電位制御を行う必要がでてく
る。
2. Description of the Related Art Conventionally, in an electrophotographic copying apparatus, a photosensitive drum is first uniformly charged (primary charged) on a photosensitive drum surface in an image forming process.
On the other hand, the reflected light of the document is applied to cause a discharge in accordance with the brightness of the static charge, thereby forming an electrostatic latent image on the drum. Therefore, in order to further improve the image quality, it is essential to control the primary charging to a predetermined value, and it is necessary to control the surface potential using a surface voltmeter.

【0003】従来の表面電位計の例を図を用いて説明
する。
[0003] The example of a conventional surface potential meter will be described with reference to FIG.

【0004】図は従来例の表面電位計の斜視図であ
る。
FIG. 7 is a perspective view of a conventional surface voltmeter.

【0005】図において、1は対向電極(測定電
極)、2は音さ、3は圧電素子、4は音さ取り付け台、
5はチョッピング用羽根、6はセンサ基板、101は感
光体ドラムである。
In FIG. 7 , 1 is a counter electrode (measurement electrode), 2 is a sound, 3 is a piezoelectric element, 4 is a sound mount,
5 is a chopping blade, 6 is a sensor substrate, and 101 is a photosensitive drum.

【0006】次に従来例の動作を図を用いて説明す
る。
[0006] will be described with reference to FIG. 7 the operation of the conventional example.

【0007】図において、まずドラム101が帯電
し、電位をもつと、ドラム101から対向電極1に、セ
ンサ基板6をカバーするシールドケース(図示せず)の
窓を通って、電気力線Sが入射する。
In FIG. 7 , first, when the drum 101 is charged and has a potential, the electric field lines S are transmitted from the drum 101 to the counter electrode 1 through a window of a shield case (not shown) covering the sensor substrate 6. Is incident.

【0008】一方、音さ2に取り付けられた圧電素子3
には20Vpp、500Hz程度のパルス電圧が印加さ
れ、音さ2全体に振動が発生する。これにより、音さ2
先端の羽根5の部分も同じく振動するため、ドラム10
1から対向電極1に入射する電気力線がチョッピングさ
れ、入射電気力線Sの量が変動させられ、数十MΩ程度
でグランドに接地される対向電極1上に微小な交流電圧
が誘起される。原理的にはこの信号の大きさをもとにド
ラム101上の電位を測定する。
On the other hand, the piezoelectric element 3 attached to the pitch 2
, A pulse voltage of about 20 Vpp and 500 Hz is applied, and vibration occurs in the entire pitch 2. Thereby, the pitch 2
Since the tip blade 5 also vibrates similarly, the drum 10
1 is chopped from the line of electric force incident on the counter electrode 1, the amount of the line of electric force S incident on the counter electrode 1 is fluctuated, and a minute AC voltage is induced on the counter electrode 1 grounded to ground at about several tens MΩ. . In principle, the potential on the drum 101 is measured based on the magnitude of this signal.

【0009】この場合、羽根5の振れ幅が十分大きく、
また測定電極1の大きさが十分大きければチョッピング
される電気力線Sの量もそれに応じて大きくなり、被測
定物体以外からの信号混入を無視できる充分なS/N比
をもった信号を出力することが可能である。
In this case, the swing width of the blade 5 is sufficiently large,
Also, if the size of the measuring electrode 1 is sufficiently large, the amount of the electric flux lines S to be chopped increases accordingly, and a signal having a sufficient S / N ratio that can ignore signal mixing from other than the object to be measured is output. It is possible to

【0010】[0010]

【発明が解決しようとする課題】しかしながら、装置全
体の小型化が進むなかで、表面電位計に対する小型化の
要求も近年とみに増しており、例えば、40φ程度の小
径の感光体ドラムを用いた複写機では通常の電子写真用
基本ユニットをドラムまわりに配備すると1cm程度の厚
みのある従来型表面電位計はもはや設置する空間がなく
なるという課題があった
However, with the progress of miniaturization of the entire apparatus, the demand for miniaturization of the surface voltmeter has been increasing in recent years. For example, copying using a photoreceptor drum having a small diameter of about 40.phi. When the conventional electrophotographic basic unit is arranged around the drum, there is a problem that the space for installing the conventional surface electrometer having a thickness of about 1 cm no longer exists .

【0011】 また、この表面電位計に求められる精度
は、画像の高画質化の要求とともに上昇する一方、前記
のように本体装置の小型化に伴った表面電位計の小型化
の要求も強くなっており、これらは一般にトレードオフ
の関係にあり、単純に小型化するとS/N比の劣化をま
ねき、精度の悪化を来すことになるという課題があっ
た。
[0011] Also, the accuracy required for this surface voltmeter
Increases with the demand for higher image quality,
The size reduction of the surface voltmeter with the downsizing of the main unit
Requirements are increasing, and these are generally trade-offs.
If the size is simply reduced, the deterioration of the S / N ratio will be maintained.
There is a problem that leads to deterioration of accuracy
Was.

【0012】例えば、図において、被測定対象101
から電極1に入射する信号分と、音さ2を振動させるた
めの圧電素子3をドライブする信号の電極混入分の比
は、電極1の小型化によって前者が減少する一方、シー
ルド対策の難しさから後者が増大するため、大きく劣化
することになるという課題があった。
[0012] For example, in FIG. 7, the object to be measured 101
The ratio of the amount of the signal incident on the electrode 1 from the electrode to the amount of the mixed electrode of the signal for driving the piezoelectric element 3 for vibrating the pitch 2 is reduced by the downsizing of the electrode 1, while the difficulty in shielding measures is increased. since the latter is increased from, there is a challenge that will be significantly degraded.

【0013】この発明は上記のような課題を解決するた
めになされたもので、表面電位計の小型化,高精度化を
実現することを目的とする。
[0013] The present invention has been made to solve the above problems, the miniaturization of the front surface electrometer, a purpose to realize a high precision.

【0014】[0014]

【課題を解決するための手段】このため、対象物体の表
面に対向する測定電極と、前記対象物体と前記測定電極
の間に窓部を有する導電性シールドケースと、前記対象
物体から前記シールドケースの窓部を通り前記測定電極
に入射する電気力線を切,開するチョッピング手段と、
を有し、前記測定電極に前記対象物体の表面電位に応じ
た振幅の交流電圧を誘起させる表面電位計において、前
記チョッピング手段はチョッピングのための羽根を具備
した音さを有し、かつ前記音さの羽根の面を前記シール
ドケース窓部の外壁面位置に一致させ係合して成ること
を特徴とする表面電位計により、前記目的を達成しよう
とするものである
[SUMMARY OF To this end, the measurement electrode facing the surface of the Target object, a conductive shield case having a window portion between the measuring electrode and the object, said shield from said object Chopping means for cutting and opening lines of electric force passing through the window of the case and entering the measurement electrode;
A surface voltmeter for inducing an AC voltage having an amplitude corresponding to a surface potential of the target object on the measurement electrode, wherein the chopping means has a pitch provided with chopping blades, and the surface potential meter, characterized by comprising engagement is matched in the face of the blade to the outer wall surface position of the shield case window, it is intended to achieve the above purposes.

【0015】 [0015]

【実施例】以下、この発明の実施例を図面に基づいて説
明する
Embodiments of the present invention will be described below with reference to the drawings .

【0016】先ず、この発明の第実施例である表面電
位計について、図および図を用いて説明する。
[0016] First, the first surface potential meter is an embodiment of the present invention will be described with reference to FIGS.

【0017】図はこの発明の第実施例である表面電
位計の図であり、(a)は側断面図、(b)は平面図で
ある。図は図の第実施例に対応する従来例の図で
あり、(a)は側断面図、(b)は平面図である。
FIG. 1 is a diagram of a surface voltmeter according to a first embodiment of the present invention, in which (a) is a side sectional view and (b) is a plan view. Figure 2 is a diagram of a conventional example corresponding to the first embodiment of FIG. 1, (a) is a side sectional view, (b) is a plan view.

【0018】図と図を対比しながら第実施例の説
明をする。
The contrast to FIG. 1 and FIG. 2 will be the description of the first embodiment.

【0019】図中、前記従来例と同一符号は同一または
相当部分を示し、一部重複して説明する。
In the drawing, the same reference numerals as those in the conventional example denote the same or corresponding parts, and the description will be partially repeated.

【0020】図および図において、1は対象物から
の電気力線Sをうける測定電極、2は対象物から測定電
極1へ入射する電気力線をチョッピングする音さ、3は
音さ2を機械的に振動させるための圧電振動子、4は音
さ2を基板6に固定するための音さ固定台、5は音さの
先端部に付属したチョッピング用の羽根、6は検出信号
を処理する回路等をのせる基板、7は不要な外来ノイズ
を遮断するシールドケース、8はシールドケース7にあ
けられた窓で、対象物から電極1に電気力線Sを入射さ
せる。9は電気力線Sの入射方向、10は羽根振動方向
を示す。従来例(図)と比較した第4実施例の特徴は
シールドケースの窓を広げ、音さ2の羽根の面をシール
ドケースの外壁面の位置にあわせて取り付けたことであ
る。
1 and 2 , reference numeral 1 denotes a measuring electrode which receives a line of electric force S from an object, 2 denotes a sound for chopping electric lines of force incident on the measuring electrode 1 from the object, and 3 denotes a sound 2 Is a piezoelectric vibrator for mechanically vibrating the sound, 4 is a pitch fixing base for fixing the pitch 2 to the substrate 6, 5 is a chopping blade attached to the tip of the pitch, and 6 is a detection signal. A substrate on which a circuit to be processed is mounted, 7 is a shield case for blocking unnecessary external noise, 8 is a window opened in the shield case 7, and the lines of electric force S enter the electrode 1 from an object. Reference numeral 9 denotes an incident direction of the electric force lines S, and reference numeral 10 denotes a blade vibration direction. The feature of the fourth embodiment in comparison with the conventional example (FIG. 2 ) is that the window of the shield case is widened and the blades of the pitch 2 are mounted in accordance with the position of the outer wall surface of the shield case.

【0021】これによって、従来例図(a)では対象
物であるドラム面と電極の距離が、ドラム面101とシ
ールドケース7の距離a,シールドケース7の板厚b,
シールドケース7と音さ2の羽根の距離c,音さ2の羽
根5の板厚d,音さ2の羽根5と電極の距離eの総和で
あったのがこの実施例では、ドラム面とシールドケース
7の距離a,音さ2の羽根5の板厚d,音さ2の羽根5
と電極1の距離eの総和とすることができ、(b+c)
分だけ接近することになり、対象物と電極1の電界が強
められ、チョッピング効率が向上し、信号Sが増大す
る。よって、この効果をうけて表面電位計のさらなる小
型化,高精度化が実現する。
[0021] Thus, the distance of the drum surface and the electrode is a conventional example Figure 2 the object in (a) is the distance a of the drum surface 101 and the shield case 7, the plate thickness b of the shield case 7,
In this embodiment, the distance c between the shield case 7 and the pitch 2 blade, the plate thickness d of the pitch 2 blade 5, and the distance e between the pitch 2 blade 5 and the electrode are sums in this embodiment. The distance a of the shield case 7, the thickness d of the blade 5 having the pitch 2 and the blade 5 having the pitch 2
And the distance e between the electrode 1 and (b + c)
As a result, the electric field between the object and the electrode 1 is strengthened, the chopping efficiency is improved, and the signal S is increased. Therefore, by taking advantage of this effect, further miniaturization and higher accuracy of the surface electrometer can be realized.

【0022】次に、この発明の第実施例について図
および図を用いて説明する。
Next, FIG. 3 for the second embodiment of the present invention
And it will be described with reference to FIG.

【0023】図はこの発明の第実施例の表面電位計
を示す図であり、(a)は平面図、(b)は側断面図で
ある。図は第実施例の図に対応する従来例を示す
図であり、(a)は平面図、(b)は側断面図である。
FIG. 3 is a diagram showing the surface potential meter of a second embodiment of the present invention, (a) shows the plan view, (b) is a side sectional view. Figure 4 is a diagram showing a conventional example corresponding to FIG. 3 of the second embodiment, (a) shows the plan view, (b) is a side sectional view.

【0024】図および図において、この実施例の基
本構成は前記第実施例で示したものよりも薄型化(図
(b)中hで示した厚み)ができることであり、本出
願人が出願ずみの特願平3−71388号によって考案
され、その内容が説明されている(図に概略図を示
す)。
In FIGS. 3 and 4 , the basic structure of this embodiment is thinner than that shown in the first embodiment.
4 (b) (thickness indicated by h) is created, and the content is explained in Japanese Patent Application No. 3-71388 filed by the present applicant (the schematic diagram is shown in FIG. 8 ). .

【0025】従って、通常このような基本構成を取る場
合には羽根の厚みfもかなり薄く設計され、必然的に対
象物から電極に入射する信号分もかなり小さくなるた
め、ならんかの信号増大化が特に望まれていた。第2実
施例も第1実施例と同様に、シールドケース7の窓を広
げ、音さ2の羽根5の面をシールドケース7の外壁面の
位置にあわせて取り付けたことに特徴がある。以上の構
成により、第5実施例は前記第1実施例と同様の作用効
果を奏する。
Therefore, when such a basic structure is adopted, the thickness f of the blade is designed to be considerably small, and the signal incident on the electrode from the object is inevitably reduced considerably. Was particularly desired. As in the first embodiment, the second embodiment is characterized in that the window of the shield case 7 is widened and the surface of the blade 5 of the pitch 2 is attached to the position of the outer wall surface of the shield case 7. With the above configuration, the fifth embodiment has the same operation and effect as the first embodiment.

【0026】次にこの発明の第実施例について図
よび図を用いて説明する。
Next will be explained with reference to FIGS. 5 and 6 a third embodiment of the present invention.

【0027】図はこの発明の第実施例である表面電
位計を示す図であり、(a)は平面図、(b)は側断面
図である。図は図に対応する従来例の表面電位計の
図であり、(a)は平面図、(b)は側断面図である。
FIG. 5 is a diagram showing a third surface potential meter of an embodiment of the present invention, (a) shows the plan view, (b) is a side sectional view. Figure 6 is a diagram of a conventional example surface potential meter corresponding to FIG. 5, (a) plan view, (b) is a side sectional view.

【0028】図において、第実施例で使用される音
さ2は音さの板平面が前記第4,第5の各実施例と異な
り、音さ2の2つの板が並ぶ平面に並行になったもので
ある。先端の羽根5の部分の板平面がこれに対し、垂直
になっている。圧電素子3は音さ2の板平面上に同図に
示すように取り付けられるので羽根5の振動方向は矢印
10のようになる。第実施例も第,第の各実施例
と同様に、シールドケース7の窓を広げ、音さ2の羽根
5の面をシールドケース7の外壁面の位置にあわせて取
り付けたものであり、その作用効果も同様なものとな
る。
In FIG. 5 , the pitch 2 used in the third embodiment differs from the fourth and fifth embodiments in the plane of the pitch, and is parallel to the plane in which the two plates of the pitch 2 are arranged. It has become. The plane of the blade 5 at the tip is perpendicular to this. Since the piezoelectric element 3 is mounted on the plane of the pitch 2 as shown in FIG. In the third embodiment, similarly to the first and second embodiments, the window of the shield case 7 is widened, and the surface of the blade 5 of the pitch 2 is mounted in accordance with the position of the outer wall surface of the shield case 7. There is a similar effect.

【0029】[0029]

【発明の効果】以上説明したように、本発明によれば、
チョッピング手段としてチョッピングのための羽根を持
つ音さを用い、音さの羽根の面をシールドケースの窓の
部分のシールドケース外壁面位置に一致させることによ
り、対象物と電極の距離を短くすることが可能となり、
電極に誘起される信号分が増大し、表面電位計の小型
化、高精度化が実現できる。
As described above , according to the present invention,
Shortening the distance between the target object and the electrode by using a pitcher with chopping blades as chopping means, and matching the surface of the pitcher blade with the position of the outer wall of the shield case at the window part of the shield case Becomes possible,
The signal component induced in the electrode increases, and the miniaturization and high accuracy of the surface voltmeter can be realized.

【図面の簡単な説明】[Brief description of the drawings]

【図1】 この発明の第実施例である表面電位計の図FIG. 1 is a diagram of a surface voltmeter according to a first embodiment of the present invention.

【図2】 図の第実施例に対応する従来の図FIG. 2 is a conventional diagram corresponding to the first embodiment of FIG. 1 ;

【図3】 この発明の第実施例の表面電位計を示す図FIG. 3 is a diagram showing a surface voltmeter according to a second embodiment of the present invention;

【図4】 第実施例の図に対応する従来例を示す図FIG. 4 is a diagram showing a conventional example corresponding to FIG. 3 of the second embodiment.

【図5】 この発明の第実施例である表面電位計を示
す図
FIG. 5 is a diagram showing a surface voltmeter according to a third embodiment of the present invention.

【図6】 図に対応する従来例の表面電位計の図6 is a diagram of a conventional example surface potential meter corresponding to FIG. 5

【図7】 従来例の表面電位計の斜視図FIG. 7 is a perspective view of a conventional surface electrometer.

【図8】 特願平3−71388号に記載の表面電位計
の横断面図
FIG. 8 is a cross-sectional view of the surface voltmeter described in Japanese Patent Application No. 3-71388.

【符号の説明】[Explanation of symbols]

1 電極 2 音さ 3 圧電素子 4 音さ固定台 5 羽根 6 センサ基板 7 シールドケース 8 窓 10 羽根振動方向 S 電気力線 101 ドラム DESCRIPTION OF SYMBOLS 1 electrode 2 pitch 3 piezoelectric element 4 pitch fixing stand 5 blade 6 sensor substrate 7 shield case 8 window 10 blade vibration direction S electric flux line 101 drum

Claims (1)

(57)【特許請求の範囲】(57) [Claims] 【請求項1】 対象物体の表面に対向する測定電極と、 前記対象物体と前記測定電極の間に窓部を有する導電性
シールドケースと、 前記対象物体から前記シールドケースの窓部を通り前記
測定電極に入射する電気力線を切,開するチョッピング
手段と、 を有し、前記測定電極に前記対象物体の表面電位に応じ
た振幅の交流電圧を誘起させる表面電位計において、 前記チョッピング手段はチョッピングのための羽根を具
備した音さを有し、かつ前記音さの羽根の面を前記シー
ルドケース窓部の外壁面位置に一致させ係合して成るこ
とを特徴とする表面電位計。
1. A measurement electrode facing a surface of a target object, a conductive shield case having a window between the target object and the measurement electrode, and the measurement from the target object through a window of the shield case. A chopping means for cutting and opening lines of electric force incident on the electrode, wherein the chopping means comprises: a chopping means, wherein the measuring electrode induces an AC voltage having an amplitude corresponding to a surface potential of the target object. A surface voltmeter having a pitch provided with a blade for adjusting the pitch of the sound, wherein the surface of the pitched blade is aligned with and engaged with the position of the outer wall surface of the shield case window.
JP04204704A 1992-07-31 1992-07-31 Surface electrometer Expired - Fee Related JP3096162B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP04204704A JP3096162B2 (en) 1992-07-31 1992-07-31 Surface electrometer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP04204704A JP3096162B2 (en) 1992-07-31 1992-07-31 Surface electrometer

Publications (2)

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JPH0651006A JPH0651006A (en) 1994-02-25
JP3096162B2 true JP3096162B2 (en) 2000-10-10

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JP2006003131A (en) * 2004-06-15 2006-01-05 Canon Inc Potential sensor
JP2006317358A (en) * 2005-05-16 2006-11-24 Canon Inc Electric potential measuring device and image forming apparatus using it

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