JPS61124973A - Image forming device - Google Patents

Image forming device

Info

Publication number
JPS61124973A
JPS61124973A JP59247372A JP24737284A JPS61124973A JP S61124973 A JPS61124973 A JP S61124973A JP 59247372 A JP59247372 A JP 59247372A JP 24737284 A JP24737284 A JP 24737284A JP S61124973 A JPS61124973 A JP S61124973A
Authority
JP
Japan
Prior art keywords
toner
image
light
density
filter
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.)
Granted
Application number
JP59247372A
Other languages
Japanese (ja)
Other versions
JPH0135347B2 (en
Inventor
Keiichiro Suzuki
圭一郎 鈴木
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.)
Konica Minolta Inc
Original Assignee
Konica Minolta 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 Konica Minolta Inc filed Critical Konica Minolta Inc
Priority to JP59247372A priority Critical patent/JPS61124973A/en
Priority to CN 85104733 priority patent/CN1014363B/en
Publication of JPS61124973A publication Critical patent/JPS61124973A/en
Priority to US07/028,016 priority patent/US4799082A/en
Publication of JPH0135347B2 publication Critical patent/JPH0135347B2/ja
Granted legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
    • G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
    • G03G15/0822—Arrangements for preparing, mixing, supplying or dispensing developer
    • G03G15/0848—Arrangements for testing or measuring developer properties or quality, e.g. charge, size, flowability
    • G03G15/0849—Detection or control means for the developer concentration
    • G03G15/0855—Detection or control means for the developer concentration the concentration being measured by optical means
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/50—Machine control of apparatus for electrographic processes using a charge pattern, e.g. regulating differents parts of the machine, multimode copiers, microprocessor control
    • G03G15/5033—Machine control of apparatus for electrographic processes using a charge pattern, e.g. regulating differents parts of the machine, multimode copiers, microprocessor control by measuring the photoconductor characteristics, e.g. temperature, or the characteristics of an image on the photoconductor
    • G03G15/5041—Detecting a toner image, e.g. density, toner coverage, using a test patch
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/00025—Machine control, e.g. regulating different parts of the machine
    • G03G2215/00029—Image density detection
    • G03G2215/00033—Image density detection on recording member
    • G03G2215/00037—Toner image detection
    • G03G2215/00042—Optical detection

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Control Or Security For Electrophotography (AREA)
  • Color Electrophotography (AREA)
  • Dry Development In Electrophotography (AREA)

Abstract

PURPOSE:To obtain a image forming device which forms a sharp image which has sufficient density and superior chromatic color property stably for a long period by providing a means which adjusts the light sensitivity of a photodetecting means according to the spectral reflection factor of toner in use. CONSTITUTION:Light 30 emitted by a light emitting element 18d is passed through an optical path 18b, reflected by the surface (reference development surface) of the photosensitive drum 6, and passed through a filter 18f to enter the photodetecting element 18e through the optical path 18c. A density sensor 18 selects a filter 18f according to the spectral reflection factor to the toner in use because the quantity of reflected light is corrected by rotating or switching the filter 18f, thereby correcting sensitivity. Consequently, invariably stable and accurate density detection is performed by sensitivity adjustment even when any of different kinds of color toner is used, and development which is sufficient in density, sharp, and superior in chromatic color property is carried out.

Description

【発明の詳細な説明】 イ、産業上の利用分野 本発明は画像形成装置、例えば電子写真複写機等の静電
記録装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to an image forming apparatus, for example, an electrostatic recording apparatus such as an electrophotographic copying machine.

ロ、従来技術 例えば電子写真複写機において、近年、黒色トナーのみ
ならず、黒色以外の赤色、青色、緑色、セピア色等の有
彩色を呈するカラートナーを用いてカラー画像を形成す
る技′術が盛んに研究開発されている。B. Prior Art In recent years, for example, in electrophotographic copying machines, technology has been developed to form color images using not only black toner but also color toners that exhibit chromatic colors other than black, such as red, blue, green, and sepia. It is being actively researched and developed.

しかるに、電子写真複写機においては、一般に、原稿露
光により像担持体（例えば感光体ドラム）上に形成され
た静電荷潜像にトナー粒子を付着させて現像が行なわれ
るが、この現像プロセスにおいて潜像に付着するトナー
量が最終的に得られる画像の画質に大きな影響を与える
。このため、十分な濃度でしかも鮮明で有彩色性の優れ
た画像を得るためには、この現像プロセスにおいて潜像
に付着するトナー量が常に適正範囲内にあることが必要
である。However, in an electrophotographic copying machine, development is generally performed by attaching toner particles to an electrostatic latent image formed on an image bearing member (for example, a photoreceptor drum) by exposing a document to light. The amount of toner that adheres to an image has a large effect on the quality of the final image. Therefore, in order to obtain an image of sufficient density, clarity, and excellent chromaticity, it is necessary that the amount of toner adhering to the latent image always be within an appropriate range in this development process.

黒色トナーのみを用いて画像を形成する従来の画像形成
においては、像担持体の一部に濃度検出専用の検出領域
を設けてこの検出領域に通常のプロセスに従っていわゆ
るベタトナー像を形成し、このベタトナー像に発光素子
からの検出光を照射し、これよりの反射光を受光素子を
含む受光手段で受光する。このときの受光光量が所定の
レベルヒ越えたときには、画像濃度が低いことを指示す
る低濃度信号を発生し、この低濃度信号に基いて現検器
にトナーを補給するようにして、画像濃度の制御を行な
っている。In conventional image formation in which images are formed using only black toner, a detection area dedicated to density detection is provided in a part of the image carrier, a so-called solid toner image is formed in this detection area according to a normal process, and the solid toner image is The image is irradiated with detection light from a light emitting element, and the reflected light from this is received by a light receiving means including a light receiving element. When the amount of light received at this time exceeds a predetermined level, a low density signal indicating that the image density is low is generated, and based on this low density signal, toner is replenished to the current detector, thereby reducing the image density. is in control.

しかしながら、特に、カラートナーを用いてカラー画像
を形成する場合において、上述の黒色トナーの場合のよ
うにして画像濃度を制御すると、検出光に対する各カラ
ートナーの分光反射率の値が異なっている。このため、
カラートナーの色の種類によっては潜像へのトナー付着
量が十分であるにも拘わらず、低濃度信号が発生してし
まうことがあり、これにより、トナーが過剰補給され、
カブリが生じて画質の劣化した画像となる。また逆に、
カラートナーの色の種類によっては潜像へのトナー付着
量が不十分であるにも拘わらず、低濃度信号が発生され
ず、このためにトナーの補給がなされず、濃度が低くて
有彩色性の劣った画像となる。結局、多種の色のカラー
トナーを用いて、十分な濃度で鮮明な画像を形成するこ
とが困難である。　゛ ハ１発明の目的 本発明は、以上の如き事情に鑑みてなされたものであっ
て、その目的は、簡単に画像濃度の検出が可能であって
、十分な濃度でしかも鮮明で有彩色性の優れた画像を長
期間安定して形成することができる画像形成装置を提供
することにある。However, especially when forming a color image using color toners, if the image density is controlled as in the case of the black toner described above, the values of the spectral reflectance of each color toner with respect to the detected light differ. For this reason,
Depending on the type of color toner, even though the amount of toner adhering to the latent image is sufficient, a low density signal may occur, resulting in excessive toner replenishment.
Fog occurs, resulting in an image with degraded image quality. And vice versa,
Depending on the type of color toner, even though the amount of toner adhering to the latent image is insufficient, a low density signal is not generated, and therefore toner is not replenished, resulting in a low density and chromatic color. This results in an inferior image. As a result, it is difficult to form clear images with sufficient density using color toners of various colors.゛1 Purpose of the Invention The present invention has been made in view of the above-mentioned circumstances, and its purpose is to enable easy detection of image density, provide sufficient density, clearness, and chromatic color. An object of the present invention is to provide an image forming apparatus that can stably form excellent images over a long period of time.

二０発明の構成 即ち、本発明による画像形成装置は、像担持体上に形成
されたトナー像からの反射光を受光手段で検出し、この
検出情報を処理してトナー濃度を制御するように構成し
た画像形成装置において、使用するトナーの分光反射率
に応じて前記受光手段の光感度を調整する調整手段（或
いは光感度を変化させて補正する手段）を有することを
特徴とするものである。ここで、「トナー濃度」とは、
現像剤中のトナーの含有率のことである。20 Structure of the Invention That is, the image forming apparatus according to the present invention detects reflected light from a toner image formed on an image carrier with a light receiving means, and processes this detected information to control toner density. The image forming apparatus thus constructed is characterized by comprising an adjusting means (or a means for correcting the light sensitivity by changing it) for adjusting the light sensitivity of the light receiving means according to the spectral reflectance of the toner used. . Here, "toner density" is
This refers to the content rate of toner in the developer.

本発明の望ましい実施態様によれば、発光手段から発光
される光を感光体表面上のトナー像に投射し、このトナ
ー像からの反射光量を受光手段で検出し、この信号を検
知手段で処理してトナー濃度を制御する。また、受光手
段の感度は、入射光量をフィルタで調整することによっ
て変化させたり、或いは複数種の受光素子を選択するこ
とによって変化させることができる。また、受光手段の
感度は、トナーの種類（従って分光反射率）に応じた現
像器及びトナーホッパ等の情報（例えば突起）をもとに
、例えば現像装置の装着時に可変できるように構成する
こともできる。According to a preferred embodiment of the present invention, the light emitted from the light emitting means is projected onto the toner image on the surface of the photoreceptor, the amount of reflected light from the toner image is detected by the light receiving means, and this signal is processed by the detecting means. to control toner density. Furthermore, the sensitivity of the light receiving means can be changed by adjusting the amount of incident light with a filter, or by selecting a plurality of types of light receiving elements. Furthermore, the sensitivity of the light receiving means may be configured to be variable, for example, when the developing device is installed, based on information (for example, protrusions) about the developing device and toner hopper, etc., depending on the type of toner (therefore, the spectral reflectance). can.

二、実施例 以下、本発明の実施例を図面参照下に詳細に説明する。2. Examples Embodiments of the present invention will be described in detail below with reference to the drawings.

第１図は本実施例の濃度センサ１８の断面を示すもので
ある。センサ１８の本体１８ａに形成した光通路１８ｂ
内に臨むように発光素子としてのＬＥＤ（発光ダイオー
ド）１８ｄを設け、また光通路１８ｃ内に臨むように受
光素子としてのホトトランジスタ１８ｅを設ける。ＬＥ
Ｄ１８ｄから放出された光３０が光通路１８ｂを通過し
て怒光体ド゛ラム６の表面（基準画像面）で反射し、フ
ィルタ１８ｆを透過し、光通路１８Ｇを経由してホトト
ランジスタ１８ｅに入射するように構成されている。そ
して、ＬＥＤ１８ｄは照射光３０のピーク波長が例えば
９５０ｎｍに設定され、かつホトトランジスタｔ８ｅと
しては少なくとも上記波長の光に感度のあるものが使用
されている。FIG. 1 shows a cross section of the concentration sensor 18 of this embodiment. Optical path 18b formed in main body 18a of sensor 18
An LED (light emitting diode) 18d as a light emitting element is provided so as to face inside, and a phototransistor 18e as a light receiving element is provided so as to face inside optical path 18c. L.E.
Light 30 emitted from D18d passes through optical path 18b, is reflected on the surface of phosphor drum 6 (reference image plane), passes through filter 18f, and is transmitted to phototransistor 18e via optical path 18G. configured to be incident. The peak wavelength of the irradiated light 30 of the LED 18d is set to, for example, 950 nm, and a phototransistor t8e that is sensitive to at least the above wavelength of light is used.

この濃度センサ１８は、フィルタ１８ｆの回転又は切換
えによって反射光量を補正することができる。This density sensor 18 can correct the amount of reflected light by rotating or switching the filter 18f.

従って、使用するトナーの分光反射率に応じてこのフィ
ルタ１８ｆを選択することにより、濃度センサ１８の感
度を補正することができる。このフィルタ１８ｆには、
光透過率の異なる各フィルタ部１８ｇが設けられている
。また、フィルタ１８ｆの切換えは自動的に行なえるよ
うに構成してよいし、或いはマニュアルで切換えてもよ
い。Therefore, by selecting this filter 18f according to the spectral reflectance of the toner used, the sensitivity of the density sensor 18 can be corrected. This filter 18f has
Each filter section 18g having a different light transmittance is provided. Furthermore, the filter 18f may be configured to be switched automatically, or may be switched manually.

第２図は、濃度センサ１８からの検知信号を処理して画
像濃度信号を得るための検知回路を示すものである。こ
の検知回路では、濃度センサ１８のホトトランジスタ１
８ｅが電源電圧ＶＣＣと接地との間に抵抗Ｒ７を介して
接続され、その抵抗Ｒ７とホトトランジスタ１８ｅとの
共通接続点が演算増幅器２２の非反転入力端子に接続さ
れている。また、この演算増幅器２２０反転入力端子は
抵抗Ｒ８を介して出力端子に接続されると共に、抵抗Ｒ
９を介して接地されている。また、演算増幅器２２の出
力端子はコンパレータ２３の反転入力端子に接続されて
いる。このコンパレータ２３の非反転入力端子には電源
電圧Ｖｃｃを抵抗Ｒ５とＲ６で分割した電圧が比較基準
電圧として入力している。FIG. 2 shows a detection circuit for processing the detection signal from the density sensor 18 to obtain an image density signal. In this detection circuit, the phototransistor 1 of the concentration sensor 18
8e is connected between the power supply voltage VCC and ground via a resistor R7, and a common connection point between the resistor R7 and the phototransistor 18e is connected to the non-inverting input terminal of the operational amplifier 22. Further, the inverting input terminal of this operational amplifier 220 is connected to the output terminal via a resistor R8, and the resistor R
It is grounded via 9. Further, the output terminal of the operational amplifier 22 is connected to the inverting input terminal of the comparator 23. A voltage obtained by dividing the power supply voltage Vcc by resistors R5 and R6 is input to the non-inverting input terminal of the comparator 23 as a comparison reference voltage.

ホトトランジスタ１８ｅは入射する反射光量が多い（感
光体ドラム６上のトナー濃度が薄い）はど、そのエミッ
タ電流が多く、この電流は演算増幅器２２で電圧に変換
され、増幅される。そして、その演算増幅器２２の出力
はホトトランジスタ１８ｅへの反射光量が多いほど上昇
して、次段のコンパレータ２３に入力する。そして、こ
のコンパレータ２３において、反転入力端子への演算増
幅器２２からの出力が、非反転入力端子に印加している
基準電圧よりも上昇すると、出力電圧がローレベルとな
り、検知したトナー像の濃度が所定値よりも低いことを
示す。When the amount of reflected light incident on the phototransistor 18e is large (the toner concentration on the photosensitive drum 6 is low), its emitter current is large, and this current is converted into a voltage by the operational amplifier 22 and amplified. The output of the operational amplifier 22 increases as the amount of light reflected to the phototransistor 18e increases, and is input to the comparator 23 at the next stage. In this comparator 23, when the output from the operational amplifier 22 to the inverting input terminal rises above the reference voltage applied to the non-inverting input terminal, the output voltage becomes low level and the density of the detected toner image decreases. Indicates that the value is lower than a predetermined value.

このようにして検知された濃度を示す信号は、現像装置
の電磁弁に送られ、その電磁弁の開閉によりホッパから
のトナーの補給開始或いは停止が行なわれ、トナー濃度
が制御される。A signal indicating the density detected in this way is sent to the electromagnetic valve of the developing device, and by opening and closing the electromagnetic valve, toner supply from the hopper is started or stopped, and the toner density is controlled.

第３図は代表的なカラートナーであるブランク、セピア
、レッドの分光反射率特性を示すものである。例えば波
長が９５０ｎｍではブラックとレッドではその反射率に
大きな差があり、実験によると、その９５０ｎｍの波長
に感度を有するように受光素子を構成した場合には、ブ
ラックとレッドの反射光量の差は約３倍となる。FIG. 3 shows the spectral reflectance characteristics of typical color toners, blank, sepia, and red. For example, at a wavelength of 950 nm, there is a large difference in the reflectance between black and red.According to experiments, when a light receiving element is configured to be sensitive to the 950 nm wavelength, the difference in the amount of reflected light between black and red is Approximately 3 times as much.

そこで、本実施例では受光素子の感度を、使用するトナ
ーの分光反射率が大きい場合には低くし、小さい場合に
は高くする。例えば、上記のように９５０ｎｍの波長に
感度を持つように濃度センサ１８を構成した場合には、
ブラック・トナーとレッド・トナーが使用される複写装
置では、レッド・トナー検知の際の感度をブラック・ト
ナー検知の場合の感度に対して１／３に設定すれば良い
。Therefore, in this embodiment, the sensitivity of the light-receiving element is lowered when the spectral reflectance of the toner used is large, and increased when the spectral reflectance is small. For example, when the concentration sensor 18 is configured to be sensitive to a wavelength of 950 nm as described above,
In a copying machine that uses black toner and red toner, the sensitivity for red toner detection may be set to 1/3 of the sensitivity for black toner detection.

上記濃度センサ１８は、第４図、第５図に示す如（に配
置されてよい（但、フィルタ１８ｆは図示省略した）。The concentration sensor 18 may be arranged as shown in FIGS. 4 and 5 (however, the filter 18f is not shown).

感光体６上に形成された基準像の潜像が現像装置によっ
て現像されてなるトナー濃度制御画像３２は発光素子１
８ｄの光を受けて反射して受光素子１８ｅへ反射する。A toner density control image 32 obtained by developing a latent image of the reference image formed on the photoreceptor 6 by a developing device is generated by the light emitting element 1.
The light of 8d is received and reflected to the light receiving element 18e.

又、転写部を通過した転写紙９が感光体６から分離され
なかったとき感光体６上に巻付くので、この転写紙７の
ジャムを検知することができる。なお、図中の６ａは画
像域、６ｂは非画像域である。Furthermore, since the transfer paper 9 that has passed through the transfer section is not separated from the photoreceptor 6 and wraps around the photoreceptor 6, a jam of the transfer paper 7 can be detected. Note that 6a in the figure is an image area, and 6b is a non-image area.

第６図は、本実施例による電子写真複写機の要部を示す
ものである。FIG. 6 shows the main parts of the electrophotographic copying machine according to this embodiment.

プラテンガラス１の面上に原稿２をセットして複写開始
釦を操作すると、露光用光源３が原稿２を相対的に露光
走査して、その原稿２の光像がミラー４．５を経由して
像形成用感光体としての感光体ドラム６の表面に導びか
れる。この感光体ドラム６は接地された金属筒の外周面
にセレン等でなる光導電層を設けたもので、上記露光走
査と連動して矢印ａ方向に回転する。この感光体ドラム
６は光像が到来する以前に、直流高圧が印加された帯電
極７によって上記光導電層が例えば正に一様に帯電され
ており、この状態の光導電層が光像を受けると、その光
を受けた部分の導電率が高くなってその部分の帯電電荷
が金属筒に逃げ、暗い部分には明暗の程度に応じて正の
電荷が残るようになり、これによって光導電層の面に原
稿の像に対応した静電潜像が形成される。この静電潜像
の形成された部分が現像装置８の現像スリーブ８ａの部
分に至ると、その感光体ドラム６における残っている正
電荷の部分に負電荷を持ったトナーが静電力で吸着され
る。この結果、感光体ドラム６の表面には静電潜像に応
じたトナー像が形成される。When the original 2 is set on the surface of the platen glass 1 and the copy start button is operated, the exposure light source 3 scans the original 2 for exposure, and the light image of the original 2 passes through the mirror 4.5. and is guided to the surface of a photoreceptor drum 6, which serves as an image-forming photoreceptor. The photosensitive drum 6 is a grounded metal cylinder with a photoconductive layer made of selenium or the like provided on the outer peripheral surface thereof, and rotates in the direction of arrow a in conjunction with the exposure scanning. Before the arrival of the optical image on the photosensitive drum 6, the photoconductive layer is, for example, uniformly charged by a charging electrode 7 to which a DC high voltage is applied, and the photoconductive layer in this state does not carry the optical image. When exposed to light, the conductivity of the part that receives the light increases, and the electrical charge in that part escapes to the metal tube, leaving a positive charge in the dark part depending on the degree of brightness, and this causes photoconductivity. An electrostatic latent image corresponding to the image of the original is formed on the surface of the layer. When the portion on which this electrostatic latent image is formed reaches the developing sleeve 8a of the developing device 8, the negatively charged toner is attracted to the remaining positively charged portion of the photoreceptor drum 6 by electrostatic force. Ru. As a result, a toner image corresponding to the electrostatic latent image is formed on the surface of the photoreceptor drum 6.

転写紙９は、給紙カセット１０から、その転写紙９の先
端と上記トナー像の先端とが一致するようなタイミング
で搬送ベルト１１によって送り出され、その送り出され
た転写紙９に直流高圧が印加された転写極１２によって
、上記感光体ドラム６の表面のトナー像が転写される。The transfer paper 9 is sent out from the paper feed cassette 10 by the conveyor belt 11 at a timing such that the leading edge of the transfer paper 9 and the leading edge of the toner image coincide, and a DC high voltage is applied to the delivered transfer paper 9. The toner image on the surface of the photosensitive drum 6 is transferred by the transferred transfer pole 12 .

この後、交流高圧が印加された分離極１３及び分離爪１
４によって感光体ドラム６から転写紙９が分離され、搬
送ベルト１５で定着装置１６に送られてトナー像が定着
され、受は皿１７に排出され１８は、基準画像のトナー
像の濃度を検知する上述した光反射型の濃度センサ（感
光体ドラム６の表面から分離されずに巻き付いたまま到
来する転写紙も検出する）、１９は感光体ドラム６の帯
電電荷を除去する除電極、２０は感光体ドラム６の表面
に残留したトナーを除去するクリーニング装置である。After that, the separation electrode 13 and separation claw 1 to which AC high voltage was applied
4 separates the transfer paper 9 from the photosensitive drum 6, and sends it to a fixing device 16 by a conveyor belt 15, where the toner image is fixed.The receiver is discharged onto a tray 17, and 18 detects the density of the toner image of the reference image. The above-mentioned light reflection type density sensor (also detects the transfer paper that is wrapped around the surface of the photoreceptor drum 6 without being separated from it), 19 is a removing electrode for removing the electrical charge on the photoreceptor drum 6, and 20 is a removing electrode. This is a cleaning device that removes toner remaining on the surface of the photoreceptor drum 6.

上記したように、濃度センサ１８は、感光体ドラム６に
形成された基準画像のトナー像の濃度を検知するもので
ある。この基準画像は、濃度基準板２１の画像を、光学
系が本来の露光走査の速度に達する以前に感光体ドラム
６に導いて静電潜像とした後に現像装置８によって現像
した像であり、濃度センサ１８から出力するこの基準画
像のトナー像の濃度信号によって現像装置８のホッパ８
ｂの現像剤のトナー補給装置としての電磁弁８ｃの開閉
を制御してトナー濃度（即ち、二成分現像剤中のトナー
の含有率）を制御している。As described above, the density sensor 18 detects the density of the toner image of the reference image formed on the photoreceptor drum 6. This reference image is an image obtained by guiding the image on the density reference plate 21 to the photoreceptor drum 6 to form an electrostatic latent image before the optical system reaches the original exposure scanning speed, and then developing it with the developing device 8. The density signal of the toner image of this reference image output from the density sensor 18 causes the hopper 8 of the developing device 8
The toner concentration (that is, the content rate of toner in the two-component developer) is controlled by controlling the opening and closing of the electromagnetic valve 8c as a toner replenishing device for the developer b.

第７図は本発明の他の実施例を示すものである。FIG. 7 shows another embodiment of the invention.

この例による検知回路では、濃度センサ１８が複数、例
えば３種類のホトトランジスタ１８ｅ＋。In the detection circuit according to this example, the concentration sensor 18 includes a plurality of, for example, three types of phototransistors 18e+.

１８ｅｚ、１８ｅ、を有し、これらのホトトランジスタ
が電源電圧ＶＣＣと接地との間に抵抗Ｒ７を介して接続
され、その抵抗Ｒ７とホトトランジスタ１８ｅ、〜１８
ｅ３との共通接続点が演算増幅器２２の非反転入力端子
に接続されており、スイッチ２５の切換えによってホト
トランジスタ１８ｅ＋〜１８ｅ３が選択されるようにな
っている。ホトトランジスタ１８ｅ、、　１８ｅｚ、１
８ｅ３はそれぞれ、感度が異なっている。例えば、ブラ
ック・トナーの濃度を検知する場合を１８ｅ１のホトト
ランジスタでおこない、レッド・トナーの濃度を検知す
る場合を感度が１８８１より１／３程低くした１８ｅ２
のホトトランジスタでおこなう。18ez, 18e, these phototransistors are connected between the power supply voltage VCC and ground via a resistor R7, and the resistor R7 and the phototransistors 18e, to 18
A common connection point with e3 is connected to the non-inverting input terminal of the operational amplifier 22, and phototransistors 18e+ to 18e3 are selected by switching the switch 25. Phototransistors 18e, 18ez, 1
The 8e3s have different sensitivities. For example, when detecting the density of black toner, an 18e1 phototransistor is used, and when detecting the density of red toner, an 18e2 phototransistor is used, which has a sensitivity about 1/3 lower than that of the 1881.
This is done using a phototransistor.

ホトトランジスタ１８ｅＩ〜１８ｅ３は入射する反射光
量が多い（感光体ドラム６上のトナー濃度が薄い）はど
、そのエミッタ電流が多く、この電流は演算増幅器２２
で電圧に変換され、増幅される。そして、その演算増幅
器２２の出力はホトトランジスタへの反射光量が多いほ
ど上昇して、次段のコンパレータ２３に入力する。そし
て、このコンパレータ２３において、反転入力端子への
演算増幅器２２からの出力が、非反転入力端子に印加し
ている基準電圧よりも上昇すると、出力電圧がローレベ
ルとなり、検知したトナー像の濃度が所定値よりも低い
こと“を示す。When the amount of reflected light incident on the phototransistors 18eI to 18e3 is large (the toner concentration on the photoreceptor drum 6 is low), the emitter current is large, and this current is transferred to the operational amplifier 22.
is converted into voltage and amplified. The output of the operational amplifier 22 increases as the amount of light reflected to the phototransistor increases, and is input to the comparator 23 at the next stage. In this comparator 23, when the output from the operational amplifier 22 to the inverting input terminal rises above the reference voltage applied to the non-inverting input terminal, the output voltage becomes low level and the density of the detected toner image decreases. "is lower than a predetermined value."

なお、上記した切換スイッチ２５の切換えは、装着した
現像装置に応じて、例えばその現像装置の現像器或いは
ホッパ等にカラートナーの種類毎に異なる突起やバーコ
ードを設けておいて、その現像装置を装着すれば自動的
に切換えられるようにすることができる。或いは、マニ
ュアルで切換えるようにしてもよい。Note that the switching of the above-mentioned changeover switch 25 can be carried out depending on the installed developing device, for example by providing different protrusions or bar codes for each type of color toner on the developing device or hopper of that developing device. If you install the , it can be switched automatically. Alternatively, the switching may be performed manually.

以上、本発明を例示したが、上述の実施例は本発明の技
術的思想に基いて更に変形可能である。Although the present invention has been illustrated above, the embodiments described above can be further modified based on the technical idea of the present invention.

例えば、受光素子等の受光手段の光感度調整手段は上述
したフィルタ１８ｆや切換スイッチ２５に限定されない
し、その構造、配置、操作法等も種々変更してよい。ま
た、本発明は３種のカラートナーを使用する場合の他、
３種類より多くのカラートナーを使用する場合あるいは
２種の場合にも適用することができることは勿論である
。感光体上に静電潜像を形成する手段は、通常の電子写
真複写機に採用されている露光ユニットに限らず、ＣＲ
Ｔを適用したり、或いは上記露光ユニットとＣＲＴとを
併用することもできる。また、像担持体としては前記感
光体として上述のドラム状以外にも、ベルト状のもので
も誘電体ドラムでも使用可能である。For example, the light sensitivity adjusting means of the light receiving means such as the light receiving element is not limited to the above-described filter 18f and changeover switch 25, and the structure, arrangement, operation method, etc. thereof may be changed in various ways. In addition to the case where three types of color toners are used,
Of course, the present invention can also be applied to cases where more than three types of color toners or two types of color toners are used. The means for forming an electrostatic latent image on the photoreceptor is not limited to the exposure unit employed in ordinary electrophotographic copying machines;
It is also possible to apply T, or to use the above exposure unit and CRT together. Further, as the image carrier, in addition to the above-mentioned drum shape as the photoreceptor, a belt shape or a dielectric drum can also be used.

更に、上述の装置において、前記トナーとして、８００
ｎｍ以上のいずれかの波長の光における分光比反射率が
７０〜９５％である赤色、青色、緑色、オレンジ色、黄
色等の第一群と、同分光比反射率が２０〜６０％である
ダークブルー色、セピア色、モスグリーン色等の第二群
と同分光比反射率が１０％以下である黒色等の第三群と
のいずれかの群に属するよう調色されたトナーを用い、
像担持体上に照射されて反射された８００ｎｒｎ以上の
波長の光を検出しながら画像を形成してよい。この場合
には、８００ｎｍ以上の波長の光である同一波長の検出
光を用いて、画像の形成においては、現像に用いられる
トナーが属する群に対応する設定光量値を基準としてト
ナー像におけるトナー付着量の適否をそのトナーの色の
種類に応じて適正に検出することができ、その結果、ト
ナーの色に拘わらず常にトナー補給を好適に行なうこと
ができる。しかも、受光素子の感度調整を上記わずかに
三群に対応して行なえばすみ、同調整が容易となる。Furthermore, in the above-described apparatus, the toner may contain 800
The first group, such as red, blue, green, orange, and yellow, has a spectral reflectance of 70 to 95% for light with any wavelength of nm or more, and the same spectral reflectance is 20 to 60%. Using a toner that has been toned to belong to one of the second group, such as dark blue, sepia, and moss green, and the third group, such as black, which has a spectral reflectance of 10% or less,
An image may be formed while detecting light with a wavelength of 800 nrn or more that is irradiated onto the image carrier and reflected. In this case, in image formation, toner adhesion in the toner image is determined based on the set light amount value corresponding to the group to which the toner used for development belongs, using detection light of the same wavelength, which is light with a wavelength of 800 nm or more. The appropriateness of the amount can be appropriately detected depending on the type of color of the toner, and as a result, toner replenishment can always be carried out suitably regardless of the color of the toner. Moreover, the sensitivity adjustment of the light receiving element only needs to be performed corresponding to the three groups mentioned above, and the adjustment becomes easy.

へ１発明の作用効果 本発明は上述した如く、使用するトナーの分光反射率に
応じて受光手段の光感度を調整しているので、特に種類
の異なるカラートナーのいずれを用いても感度調整によ
って常に安定かつ正確な濃度検出が可能となり、十分な
濃度で鮮明で有彩色性に優れた画像を得ることができる
。1. Effects of the Invention As described above, the present invention adjusts the photosensitivity of the light receiving means according to the spectral reflectance of the toner used. Stable and accurate density detection is always possible, and images with sufficient density, clarity, and excellent chromaticity can be obtained.

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

図面は本発明の実施例を示すものであって、第１図は濃
度センサ及びその感度調整手段を示す一部断面概略図、 第２図及び第７図は検知回路の二側の各等価回路図、 第３図はトナーの分光反射率を比較して示す特性図、 第４図はトナー濃度制御画像からの反射光をセンサで受
光する状況を示す斜視図、 第５図は記録紙の分離不良（祇づまり）をセンサで検知
する状況を示す斜視図、 第６図は電子写真複写機の要部概略図 である。 なお、図面に示した符号において、 ６−−−−−−−−・−感光体ドラム ６ａ−・−・−−−−一・画像域 ６　ｂ−−−−−−−−−−一非画像域８−−−−−−
−−−−一現像装置 ８　ａ−−−−−−−−−−−一現像スリーブ８ｂ・−
ローーーーーーーーーホンバ ８　ｃ−−−−−一・−−−−一電磁弁９〜−−−−−
−−−−−転写紙 １８−−−−−−−−−−−一濃度センサ１８ｄ　−−
−−−−−一発光素子 １８ｅ−１８ｅイ１８ｅｚ、１８ｅ：＋　−−−−−−
一受光素子１８ｆ　−−−−−−−〜フィルタ １８ｇ−−−−−−フィルタ部 ２１・−−−−−−−−ｍ−濃度基準板２２−−−−−
−−・−・−・演算増幅器２３−・−−一−−−−コン
パレータ ２５−−−−−−−−−−−−スイッチである。 代理人　弁理士　　逢　坂　　　末 弟１図 第２図 第３図 ＝ｌｔ　ｌ　　ｘｌｏｏｎｍ 第６図 第４図The drawings show an embodiment of the present invention, and FIG. 1 is a partial cross-sectional schematic diagram showing a concentration sensor and its sensitivity adjustment means, and FIGS. 2 and 7 are equivalent circuits on the two sides of the detection circuit. Figure 3 is a characteristic diagram comparing the spectral reflectance of toner, Figure 4 is a perspective view showing how the sensor receives reflected light from the toner density control image, Figure 5 is separation of recording paper. FIG. 6 is a perspective view showing a situation in which a defect (jam jam) is detected by a sensor. FIG. 6 is a schematic diagram of the main parts of an electrophotographic copying machine. In addition, in the reference numerals shown in the drawings, 6----------Photosensitive drum 6a-------1 Image area 6b-- Image area 8------
--- Developing device 8 a --- Developing sleeve 8 b.
Low------Homba 8 c----1・----1 Solenoid valve 9～------
------Transfer paper 18-----One density sensor 18d ---
------One light emitting element 18e-18e 18ez, 18e:+ --------
- Light-receiving element 18f ------- Filter 18g ------- Filter section 21 -------m - Density reference plate 22 -------
----------------------------------------------------------- Agent Patent Attorney Aisaka Youngest Brother 1 Figure 2 Figure 3 = lt l xloonm Figure 6 Figure 4

Claims (1)

【特許請求の範囲】[Claims] １、像担持体上に形成されたトナー像からの反射光を受
光手段で検出し、この検出情報を処理してトナー濃度を
制御するように構成した画像形成装置において、使用す
るトナーの分光反射率に応じて前記受光手段の光感度を
調整する調整手段を有することを特徴とする画像形成装
置。1. Spectral reflection of the toner used in an image forming apparatus configured to detect reflected light from a toner image formed on an image carrier with a light receiving means and process this detected information to control toner density. An image forming apparatus comprising: an adjusting means for adjusting the photosensitivity of the light receiving means in accordance with the rate.
JP59247372A 1984-02-02 1984-11-22 Image forming device Granted JPS61124973A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP59247372A JPS61124973A (en) 1984-11-22 1984-11-22 Image forming device
CN 85104733 CN1014363B (en) 1984-11-22 1985-06-20 Xerographic printer
US07/028,016 US4799082A (en) 1984-02-02 1987-03-18 Electrostatic reproducing apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59247372A JPS61124973A (en) 1984-11-22 1984-11-22 Image forming device

Publications (2)

Publication Number Publication Date
JPS61124973A true JPS61124973A (en) 1986-06-12
JPH0135347B2 JPH0135347B2 (en) 1989-07-25

Family

ID=17162447

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59247372A Granted JPS61124973A (en) 1984-02-02 1984-11-22 Image forming device

Country Status (2)

Country Link
JP (1) JPS61124973A (en)
CN (1) CN1014363B (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62127779A (en) * 1985-11-28 1987-06-10 Mita Ind Co Ltd Toner concentration detecting device
JPS63177162A (en) * 1987-01-19 1988-07-21 Canon Inc Image forming device
JPS63197366U (en) * 1987-06-08 1988-12-19
JPH1063058A (en) * 1996-08-13 1998-03-06 Konica Corp Controller for image forming process
US7206530B2 (en) 2003-11-11 2007-04-17 Samsung Electronics Co., Ltd. Control method for correcting sensitivity of toner density sensor of image forming apparatus

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS50119639A (en) * 1974-03-01 1975-09-19
JPS54143144A (en) * 1978-04-14 1979-11-08 Konishiroku Photo Ind Co Ltd Image density detecting method and apparatus for zerographic copier
JPS57207264A (en) * 1981-06-15 1982-12-18 Canon Inc Color electrophotographic copier

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS50119639A (en) * 1974-03-01 1975-09-19
JPS54143144A (en) * 1978-04-14 1979-11-08 Konishiroku Photo Ind Co Ltd Image density detecting method and apparatus for zerographic copier
JPS57207264A (en) * 1981-06-15 1982-12-18 Canon Inc Color electrophotographic copier

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62127779A (en) * 1985-11-28 1987-06-10 Mita Ind Co Ltd Toner concentration detecting device
JPS63177162A (en) * 1987-01-19 1988-07-21 Canon Inc Image forming device
JPS63197366U (en) * 1987-06-08 1988-12-19
JPH0637414Y2 (en) * 1987-06-08 1994-09-28 株式会社リコー Reflective photo sensor
JPH1063058A (en) * 1996-08-13 1998-03-06 Konica Corp Controller for image forming process
US7206530B2 (en) 2003-11-11 2007-04-17 Samsung Electronics Co., Ltd. Control method for correcting sensitivity of toner density sensor of image forming apparatus

Also Published As

Publication number Publication date
CN85104733A (en) 1986-05-10
JPH0135347B2 (en) 1989-07-25
CN1014363B (en) 1991-10-16

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