JP2002365872A - Color image forming apparatus - Google Patents
Color image forming apparatusInfo
- Publication number
- JP2002365872A JP2002365872A JP2001172576A JP2001172576A JP2002365872A JP 2002365872 A JP2002365872 A JP 2002365872A JP 2001172576 A JP2001172576 A JP 2001172576A JP 2001172576 A JP2001172576 A JP 2001172576A JP 2002365872 A JP2002365872 A JP 2002365872A
- Authority
- JP
- Japan
- Prior art keywords
- toner
- light
- base
- amount
- forming apparatus
- 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
Links
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、カラー画像形成装
置に関するものであり、特に画像濃度制御に関するもの
である。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image forming apparatus, and more particularly to image density control.
【０００２】[0002]
【従来の技術】近年、電子写真装置の画像形成装置はカ
ラー化が進められてきており、多重現像方式、中間転写
方式、静電転写ベルト方式といった各種方式が採用され
ている。2. Description of the Related Art In recent years, colorization of an image forming apparatus of an electrophotographic apparatus has been promoted, and various systems such as a multiple developing system, an intermediate transfer system, and an electrostatic transfer belt system have been adopted.
【０００３】多重現像方式では、感光ドラム上に一旦複
数色のトナー像を重ねて現像し、一括して転写材上に転
写して最終画像を形成する。In the multi-developing method, a plurality of color toner images are once superimposed on a photosensitive drum, developed, and collectively transferred onto a transfer material to form a final image.
【０００４】中間転写方式では、中間転写体上に一旦複
数色のトナー像を重ねて転写（一次転写）し、一括して
転写村上に二次転写して最終画像を形成する。In the intermediate transfer system, toner images of a plurality of colors are temporarily superimposed and transferred (primary transfer) on an intermediate transfer member, and are collectively secondarily transferred onto a transfer village to form a final image.
【０００５】静電転写体方式では、静電転写体に転写紙
を吸着させ、転写材上でトナー像を重ねあわせて画像を
形成する。In the electrostatic transfer method, an image is formed by adsorbing a transfer sheet on an electrostatic transfer member and superimposing a toner image on a transfer material.
【０００６】どの方式にしても長所短所を有し一長一短
であるが、いずれの方式を採用しようとも、使用する環
境の変化やプリント枚数等の諸条件によるちょっとした
画像濃度変動によって、本来の正しい色調が得られなく
なってしまうという欠点が存在する。Each method has advantages and disadvantages, and has advantages and disadvantages. However, no matter which method is adopted, the original correct color tone can be obtained due to a slight change in image density due to a change in the use environment or various conditions such as the number of prints. There is a disadvantage that it cannot be obtained.
【０００７】そこで、電子写真方式のカラー画像形成装
置においては、各色のトナーで濃度検知用トナー像（パ
ッチ）を試験的にそれぞれ形成し、それらのトナー量を
濃度センサで検知して画像形成条件にフィードバックす
るという画像濃度制御を行うのが一般的である。通常、
画像濃度制御は、まず、各色の最大濃度を一定に保つ事
を目的とする最大濃度制御が実施され、続いて、ハーフ
トーンの階調特性を画像信号に対して常に一定に保つこ
とを目的とするハーフトーン制御が実施される。Therefore, in an electrophotographic color image forming apparatus, a toner image (patch) for density detection is formed on a trial basis with toner of each color, and the amount of the toner is detected by a density sensor to determine image forming conditions. In general, the image density is controlled by feeding back the image density. Normal,
In image density control, first, maximum density control for the purpose of keeping the maximum density of each color constant is carried out, and subsequently, the purpose of keeping the halftone gradation characteristics always constant for the image signal. Halftone control is performed.
【０００８】図７はパッチＴのトナー付着量を測定する
濃度センサ１２であり、１２ａはＬＥＤ等の発光素子、
１２ｂはフォトダイオード等の受光素子である。パッチ
Ｔは、多重現像方式だと感光体を下地に、中間転写方式
だと中間転写体を下地に、静電転写ベルト方式だと静電
転写ベルトを下地にして形成される場合が一般的であ
る。FIG. 7 shows a density sensor 12 for measuring the amount of toner adhering to the patch T. Reference numeral 12a denotes a light emitting element such as an LED,
12b is a light receiving element such as a photodiode. In general, the patch T is formed using a photoreceptor as a base in the case of the multi-developing method, an intermediate transfer member as a base in the case of the intermediate transfer method, and an electrostatic transfer belt as a base in the case of the electrostatic transfer belt method. is there.
【０００９】[0009]
【発明が解決しようとする課題】発光素子１２ａから測
定光Ｌ１が照射されると、パッチＴの下地表面から反射
された光Ｌ２が受光素子１２ｂに入射し、受光信号が出
力される。パッチＴのトナー付着量が多い場合、反射光
Ｌ２がトナーによって多く遮光されるので受光素子１２
ｂの受光量が減少し、パッチＴのトナー付着量が少ない
場合、上記とは逆に反射光Ｌ２が多くなるので受光素子
１２ｂの受光量が増大する。すなはち、パッチＴが下地
を覆い尽くしている場合に受光信号が最小となり、パッ
チＴが存在しない場合に受光信号が最大となる。When the measurement light L1 is emitted from the light emitting element 12a, the light L2 reflected from the base surface of the patch T is incident on the light receiving element 12b, and a light receiving signal is output. When the amount of toner attached to the patch T is large, the reflected light L2 is largely blocked by the toner.
When the amount of received light of b decreases and the amount of toner adhering to the patch T is small, the amount of light received by the light receiving element 12b increases because the amount of reflected light L2 increases, contrary to the above. That is, when the patch T completely covers the base, the light receiving signal becomes minimum, and when the patch T does not exist, the light receiving signal becomes maximum.
【００１０】パッチＴが存在しない場合の受光信号が一
番大きく得られる受光素子１２ｂの位置は、発光素子１
２ａと受光素子１２ｂはパッチＴ面に対して、同一角度
をなすように配置されている場合であるため、図７に示
したように配置するのが好ましい。When the patch T is not present, the position of the light receiving element 12b where the light receiving signal can be obtained the largest is the light emitting element 1
Since 2a and the light receiving element 12b are arranged at the same angle with respect to the patch T surface, they are preferably arranged as shown in FIG.
【００１１】図８は上記濃度センサでＫトナーを測定し
た結果である。横軸はトナー付着量、縦軸は受光量であ
る。トナー付着量が増加するにしたがって受光量も減少
しており、正確にトナー付着量を測定できる。FIG. 8 shows the result of measuring the K toner by the density sensor. The horizontal axis is the toner adhesion amount, and the vertical axis is the light reception amount. As the amount of adhered toner increases, the amount of received light also decreases, and the amount of adhered toner can be accurately measured.
【００１２】図９は上記濃度センサでＫ以外の色トナー
を測定した結果である。横軸はトナー付着量、縦軸は受
光量である。最初はトナー付着量が増加するにしたがっ
て受光量も減少しているが、トナー付着量がある一定量
（図中ではＰで示した）に達すると、逆に受光量が増大
しており、正確にトナー付着量を測定できない。FIG. 9 shows the result of measuring the color toners other than K by the density sensor. The horizontal axis is the toner adhesion amount, and the vertical axis is the light reception amount. At first, the amount of received light decreases as the amount of adhered toner increases. However, when the amount of adhered toner reaches a certain amount (indicated by P in the figure), the amount of received light increases inversely. Cannot measure the amount of toner adhered to
【００１３】この現象を図１０で説明する。受光素子１
２ｂに入射する光Ｌ２は下地表面上のトナー付着量によ
って増減する。しかしながら、トナー部分による散乱反
射光成分である反射光Ｌ３が受光素子１２ｂに入射して
しまうからである。Ｋトナーの場合、ほとんど光を吸収
し反射しないため、トナー付着量が増えても反射光Ｌ３
はゼロに近く図８に示すような結果となっているが、色
トナーの場合、トナー付着量が多くなると、下地表面か
らの反射光Ｌ２は減少するにも関わらず、トナー部分に
よる反射光Ｌ３が増大するため、図９に示すような結果
となるわけである。This phenomenon will be described with reference to FIG. Light receiving element 1
The light L2 incident on the base 2b increases or decreases depending on the amount of toner adhering to the base surface. However, this is because reflected light L3, which is a scattered reflected light component of the toner portion, enters the light receiving element 12b. In the case of the K toner, almost no light is absorbed and reflected, so that the reflected light L3
8 is close to zero, and the result is as shown in FIG. 8. However, in the case of the color toner, when the amount of toner adhesion increases, the reflected light L3 from the toner portion decreases although the reflected light L2 from the base surface decreases. Is increased, and the result is as shown in FIG.
【００１４】また、図１１に示すように受光素子１２ｂ
をパッチＴ面の法線方向に配置した場合、下地表面が鏡
面に近いならば、下地部分による反射光Ｌ２は受光素子
１２ｂに入射することなく、色トナー部分からの散乱反
射光Ｌ３を受光検知することが可能となるが、下地から
の反射光成分が受光できないと、Ｋトナーを検知するこ
とが不可能となってしまう。これを防止するには、下地
表面を鏡面化せず、散乱反射するよう加工すれば良いわ
けであるが、そうすると、結局色トナー検知時に色トナ
ー部分からの反射成分と下地部分からの反射成分を分離
できないという問題が再度発生してしまう。Also, as shown in FIG.
Is arranged in the normal direction of the patch T surface, and if the underlying surface is close to the mirror surface, the reflected light L2 from the underlying portion does not enter the light receiving element 12b, and the scattered reflected light L3 from the color toner portion is detected. However, if the reflected light component from the base cannot be received, the K toner cannot be detected. To prevent this, the surface of the base may be processed so as to be scattered and reflected instead of being mirror-finished. However, in this case, when the color toner is detected, the reflection component from the color toner portion and the reflection component from the base portion are eventually reduced. The problem of inability to separate occurs again.
【００１５】つまり、従来方式では、下地からの反射光
Ｌ２と色トナー部分からの反射光Ｌ３とを確実に分離す
ることができないため、検知精度が劣っていたわけであ
る。That is, in the conventional method, the reflected light L2 from the base and the reflected light L3 from the color toner portion cannot be reliably separated, so that the detection accuracy is inferior.
【００１６】そこで、本発明は、色トナーにおいてもト
ナーの付着量を正確に測定する方法を実現することを目
的とする。SUMMARY OF THE INVENTION It is an object of the present invention to realize a method for accurately measuring the amount of toner attached to a color toner.
【００１７】[0017]
【課題を解決するための手段】（１） 上記目的を達成
する為、本出願に係わる第１の発明は、照射手段により
トナー像部分へ光を照射し、受光手段によりその反射光
を受光しトナー像濃度を検知するカラー画像形成装置に
おいて、反射率の高いトナーの濃度を測定する場合に
は、まず反射率の低いトナーの下地を形成した後、下地
の上に反射率の高いのトナー像を形成して濃度検知を実
行する。Means for Solving the Problems (1) In order to achieve the above object, the first invention according to the present application irradiates a toner image portion with light by irradiating means and receives reflected light by a light receiving means. In a color image forming apparatus for detecting the density of a toner image, when measuring the density of a toner having a high reflectance, first, a base of a toner having a low reflectance is formed, and then a toner image having a high reflectance is formed on the base. Is formed and density detection is executed.
【００１８】（２） 本出願に係る第二の発明は、第一
の発明の特徴に加え、上記下地となる反射率の低いトナ
ーとは黒トナーであり、黒トナー下地の上に形成される
反射率の高いトナーとは黒以外の色トナーであることを
特徴とする。(2) In the second invention according to the present application, in addition to the features of the first invention, the low-reflectance toner serving as the base is black toner, and is formed on the black toner base. The toner having a high reflectance is a toner other than black.
【００１９】（３） 本出願に係る第三の発明は、第一
の発明の特徴に加え、上記受光手段の信号を増幅する手
段を有し、検知するトナーによって受光信号の増幅幅を
可変することを特徴とする。(3) The third invention according to the present application has, in addition to the features of the first invention, means for amplifying the signal of the light-receiving means, and the amplification width of the light-receiving signal is varied by the toner to be detected. It is characterized by the following.
【００２０】（４） 本出願に係る第四の発明は、第一
の発明の特徴に加え、反射率の高いトナーの濃度を測定
する際、反射率の低いトナーによる下地を形成した場合
に加え、下地を形成しない場合も測定し、両者の測定結
果の差分より反射率の高いトナーの濃度を検知すること
を特徴とする。(4) The fourth invention according to the present application is characterized in that, in addition to the features of the first invention, when measuring the density of the toner having a high reflectance, the fourth invention is applied to a case where a base made of a toner having a low reflectance is formed. It is also characterized in that the measurement is performed even when the base is not formed, and the density of the toner having a high reflectance is detected from the difference between the two measurement results.
【００２１】[0021]
【発明の実施の形態】（第１の実施例）図１に本実施例
に係わるカラー画像形成装置の断面図を図示する。従来
例と同様の構成、作用の部材等については同じ符号を付
して、その説明は適宜省略するものとする。(First Embodiment) FIG. 1 is a sectional view of a color image forming apparatus according to the present embodiment. The same reference numerals are given to members having the same configuration and operation as in the conventional example, and the description thereof will be omitted as appropriate.
【００２２】装置全体内には像担持体である感光ドラム
１、接触方式ローラ帯電器２、更に感光ドラム１の左辺
には、複数個の現像器４ａ、４ｂ、４ｃ、４ｄを回転可
能の支持体３で担持し設定するものである。また、現像
装置４ａ、４ｂ、４ｃ、４ｄ内には、マゼンタ（以下Ｍ
と略す）、シアン（以下Ｃと略す）、イエロー（以下Ｙ
と略す）、ブラック（以下Ｋと略す）のトナーがそれぞ
れ収容されており、また、支持体回転軸３に取り付けら
れた現像器４ａ、４ｂ、４ｃ、４ｄは現像用開口面が常
に感光ドラム面に対向するよう駆動される。装置本体内
の上方には露光装置１１が配置されている。A photosensitive drum 1, which is an image carrier, a contact roller charger 2, and a plurality of developing units 4a, 4b, 4c, 4d are rotatably supported on the left side of the photosensitive drum 1. It is carried by the body 3 and set. In the developing devices 4a, 4b, 4c and 4d, magenta (hereinafter M
), Cyan (hereinafter abbreviated as C), yellow (hereinafter Y)
) And black (hereinafter abbreviated as K) toners, respectively, and the developing units 4a, 4b, 4c, and 4d attached to the support rotating shaft 3 have the developing opening surface always at the photosensitive drum surface. It is driven to face. An exposure apparatus 11 is disposed above the apparatus main body.
【００２３】感光ドラム１は、不図示の駆動手段によっ
て図示矢印方向に駆動される。また、感光ドラム１は、
のアルミシリンダーの外周面に有機感光体（ＯＰＣ）、
Ａ−Ｓｉ、ＣｄＳ、Ｓｅ等の光導電体を塗布して構成さ
れている。The photosensitive drum 1 is driven in a direction indicated by an arrow by driving means (not shown). Also, the photosensitive drum 1
Organic photoreceptor (OPC) on the outer surface of aluminum cylinder
It is configured by applying a photoconductor such as A-Si, CdS, or Se.
【００２４】転写装置５は、転写体支持体として３本の
支持ローラ５ａ、５ｂ、５ｃを備えている。このうち１
本が駆動ローラであり、残り２本は従動である。この支
持ローラに中間転写ベルト５ｄが巻かれ、不図示の駆動
手段によって図示矢印方向に駆動される。感光ドラム１
とほぼ対向するところに一次転写ローラ６が中間転写ベ
ルト５ｄを介して配置され、支持ローラ５ｂに対向した
ところに、転写材（不図示）に転写するための二次転写
ローラ７が配置してある。また、二次転写と一次転写の
間には中間転写ベルトクリーニング装置８が設けられて
いる。The transfer device 5 includes three support rollers 5a, 5b, and 5c as a transfer body support. One of these
The book is a driving roller, and the remaining two are driven. The intermediate transfer belt 5d is wound around the support roller, and is driven by a driving unit (not shown) in a direction indicated by an arrow. Photosensitive drum 1
A primary transfer roller 6 is arranged via the intermediate transfer belt 5d at a position substantially opposed to the intermediate transfer belt, and a secondary transfer roller 7 for transferring to a transfer material (not shown) is arranged at a position opposed to the support roller 5b. is there. An intermediate transfer belt cleaning device 8 is provided between the secondary transfer and the primary transfer.
【００２５】１２は画像濃度制御用の濃度センサであ
り、中間転写ベルト５ｄ表面に向けて設けられている。Reference numeral 12 denotes a density sensor for controlling image density, which is provided toward the surface of the intermediate transfer belt 5d.
【００２６】前述の接触方式ローラ帯電器２によって、
感光ドラム１を均一に帯電する。レーザドライバにＭの
画像模様に従った信号が入力されると、露光装置１１よ
りレーザ光が光路Ｌを通って感光ドラム１にレーザ光が
照射され、感光ドラム１上に静電潜像が形成される。更
に感光ドラム１が矢印方向に進むと現像装置４ａによっ
て可視化される。The contact-type roller charger 2 described above
The photosensitive drum 1 is uniformly charged. When a signal in accordance with the image pattern of M is input to the laser driver, the exposure device 11 irradiates the photosensitive drum 1 with laser light through the optical path L to form an electrostatic latent image on the photosensitive drum 1. Is done. When the photosensitive drum 1 further moves in the direction of the arrow, it is visualized by the developing device 4a.
【００２７】感光ドラム１上のトナー像は、不図示の電
源から中間転写ベルト５ｄに印加された電圧によって、
転写（一次転写）される。以上の行程をＣ、Ｙ、Ｋの各
色行って形成された中間転写ベルト５ｄ上の複数色トナ
ー像は、不図示の電源から中間転写ベルト５ｄに印加さ
れた電圧によって、転写材（不図示）に転写（二次転
写）され、従来公知の加熱、加圧の定着装置９によって
溶融固着されカラー画像が得られる。現像終了後の感光
ドラム１上の転写残トナーは感光ドラムクリーニング装
置１０によって清掃される。二次転写終了後の転写ベル
ト上の転写残トナーは中間転写ベルトクリーニング装置
８によって除去される。The toner image on the photosensitive drum 1 is changed by a voltage applied from a power source (not shown) to the intermediate transfer belt 5d.
It is transferred (primary transfer). The multi-color toner image formed on the intermediate transfer belt 5d by performing the above process for each of the colors C, Y, and K is transferred to a transfer material (not shown) by a voltage applied to the intermediate transfer belt 5d from a power supply (not shown). (Secondary transfer), and are fused and fixed by a conventionally known heating and pressure fixing device 9 to obtain a color image. After the development, the transfer residual toner on the photosensitive drum 1 is cleaned by the photosensitive drum cleaning device 10. The transfer residual toner on the transfer belt after the completion of the secondary transfer is removed by the intermediate transfer belt cleaning device 8.
【００２８】それでは、本実施例における画像濃度制御
について述べる。電源オン時等に画像濃度制御が実施さ
れる場合、まず、Ｋトナーによる下地トナー層Ｔｋが中
間転写ベルト５ｄ上に形成される。次に制御対象の色ト
ナーパッチＴｃがＫの下地トナー層Ｔｋ上に形成され、
濃度センサ１２により測定される。図２はパッチのトナ
ー付着量を測定する際の本実施例における模式図であ
る。Next, the image density control in this embodiment will be described. When image density control is performed when the power is turned on or the like, first, a base toner layer Tk of K toner is formed on the intermediate transfer belt 5d. Next, a color toner patch Tc to be controlled is formed on the K base toner layer Tk,
It is measured by the density sensor 12. FIG. 2 is a schematic diagram in the present embodiment when measuring the amount of toner attached to the patch.
【００２９】１２ａはＬＥＤ等の発光素子、１２ｂはフ
ォトダイオード等の受光素子である。発光素子１２ａと
受光素子１２ｂはパッチＴ面に対して、同一角度をなす
ように配置されている。発光素子１２ａからの測定光が
パッチヘ照射された時、色トナーパッチＴｃによる反射
光Ｌ３のみが受光素子１２ｂへ入射される。これは、従
来存在した中間転写ベルト５ｄ表面による反射光成分Ｌ
２が、Ｋの下地トナー層Ｔｋにより吸収され存在しなく
なってしまうからである。受光素子１２ｂによって反射
光Ｌ３のみがアナログ信号として検出され、Ａ／Ｄ変換
された信号はＣＰＵへと送信され演算される。図３はＫ
の下地トナー層Ｔｋ上に形成された色トナーを濃度セン
サ１２で測定した結果である。横軸は色トナー付着量、
縦軸は受光量である。色トナーの付着量が増加するにし
たがって受光量が増大しており、色トナーの付着量を正
確に測定することができるわけである。Reference numeral 12a denotes a light emitting element such as an LED, and 12b denotes a light receiving element such as a photodiode. The light emitting element 12a and the light receiving element 12b are arranged at the same angle with respect to the patch T surface. When the patch is irradiated with the measuring light from the light emitting element 12a, only the light L3 reflected by the color toner patch Tc is incident on the light receiving element 12b. This is due to the light component L reflected by the surface of the intermediate transfer belt 5d, which has existed conventionally.
2 is absorbed by the K base toner layer Tk and no longer exists. Only the reflected light L3 is detected as an analog signal by the light receiving element 12b, and the A / D converted signal is transmitted to the CPU and calculated. FIG.
3 shows the result of measurement of the color toner formed on the base toner layer Tk of FIG. The horizontal axis is the color toner adhesion amount,
The vertical axis is the amount of received light. The amount of received light increases as the amount of color toner attached increases, so that the amount of color toner attached can be measured accurately.
【００３０】なお、発光素子１２ａと受光素子１２ｂは
パッチＴ面に対して同一角度をなすように配置したの
は、Ｋトナーのトナー付着量測定時にパッチトナーが存
在しない場合の受光信号が一番大きく得られるようにす
るためである。中間転写ベルト５ｄ上にパッチトナーが
存在しない場合の受光信号が充分得られる場合、すなは
ち、中間転写ベルト５ｄが鏡面ではなくて入射された測
定光を散乱させるような場合、Ｋトナー付着量測定も可
能となるため、受光素子１２ｂの位置はどこでも良い。The reason why the light emitting element 12a and the light receiving element 12b are arranged at the same angle with respect to the surface of the patch T is that the light receiving signal when no patch toner exists when measuring the amount of K toner adhering is the best. This is in order to obtain a large value. When a sufficient light reception signal is obtained when no patch toner is present on the intermediate transfer belt 5d, that is, when the intermediate transfer belt 5d is not a mirror surface but scatters the incident measurement light, the K toner adhesion amount Since measurement is also possible, the position of the light receiving element 12b may be anywhere.
【００３１】（第２の実施例）図４に本実施例に係わる
カラー画像形成装置の断面図を図示する。従来例と同様
の構成、作用の部材等については同じ符号を付して、そ
の説明は適宜省略するものとする。(Second Embodiment) FIG. 4 is a sectional view of a color image forming apparatus according to the present embodiment. The same reference numerals are given to members having the same configuration and operation as in the conventional example, and the description thereof will be omitted as appropriate.
【００３２】図５は実施例１における受光素子１２ｂの
受光量とトナー付着量の関係である。実線はＫトナーに
おける受光量、破線は色トナーにおける受光量である。
Ｋトナー測定時における、トナー付着量ゼロの場合、す
なはち、中間転写ベルト５ｄのみからの反射光量が一番
強いことがわかる。また、Ｋトナー付着量の増減による
受光量変化幅、すなはちＳ／Ｎ比に比較して、色トナー
付着量増減によるＳ／Ｎ比が小さいことがわかる。図５
に示したままの受光量信号をＡ／Ｄ変換すると、色トナ
ーの場合において量子化誤差が大きくなり検出精度が悪
化してしまう。そこで、本実施例においては、アナログ
の受光量信号をデジタルに変換する前に増幅器を設け
る。そして、実施例１と同様にＫトナーの下地を形成し
た上に色トナーのパッチを形成して画像濃度制御を実行
する際、Ｋトナーと色トナーとで信号増幅率を変化させ
る。すなはち、Ｋトナー濃度測定時においては増幅率を
さほど大きくせず、色トナー濃度測定時においては増幅
率を大きくするわけである。そうすることにより、色ト
ナーにおいてもＡ／Ｄ変換の際の量子化誤差が小さくな
り、精度良く画像濃度制御が実施できる。FIG. 5 shows the relationship between the amount of light received by the light receiving element 12b and the amount of adhered toner in the first embodiment. The solid line is the amount of light received by the K toner, and the dashed line is the amount of light received by the color toner.
When the toner adhesion amount is zero when measuring the K toner, it is understood that the amount of reflected light from only the intermediate transfer belt 5d is the strongest. Further, it can be seen that the S / N ratio due to the increase / decrease in the amount of color toner is smaller than the S / N ratio, ie, the width of change in the amount of received light due to the increase / decrease in the amount of K toner adherence. FIG.
A / D conversion of the received light amount signal as shown in (1) above results in a large quantization error in the case of color toner, and the detection accuracy deteriorates. Therefore, in the present embodiment, an amplifier is provided before converting an analog light reception amount signal into a digital signal. Then, in the same manner as in the first embodiment, when forming a color toner patch on a K toner base and performing image density control, the signal amplification rate is changed between the K toner and the color toner. That is, the amplification factor is not increased so much when measuring the K toner density, but is increased when measuring the color toner density. By doing so, the quantization error in the A / D conversion is reduced even for the color toner, and the image density control can be performed with high accuracy.
【００３３】（第３の実施例）従来例と同様の構成、作
用の部材等については同じ符号を付して、その説明は適
宜省略するものとする。(Third Embodiment) The same reference numerals are assigned to members having the same structure and operation as those in the conventional example, and the description thereof will be omitted as appropriate.
【００３４】色トナーのパッチＴｃを形成する際に、実
施例１と同様に下地にＫトナーがある場合Ｔｃｋと、下
地がない場合Ｔｃｎの複数パッチを、Ｋトナー下地有無
し以外は全く同一条件で形成して、Ｔｃｎに対する画像
濃度制御とＴｃｋに対する画像濃度制御を実行する。す
ると、Ｔｃｋの受光信号出力はＫトナー下地効果によっ
て色トナー部分からの反射光Ｌ３のみの出力となり、Ｔ
ｃｎの受光信号は中間転写ベルト５ｄからの反射光Ｌ２
と色トナー部分からの反射光Ｌ３が混ざった出力とな
る。そして、Ｔｃｎの受光信号出力分からＴｃｋの受光
信号出力分を引いたものを、そのパッチＴｃの信号とす
る。そうすることにより、色トナー部分からの反射光成
分Ｌ３がキャンセルされ、Ｋトナーの場合と同様に中間
転写ベルト５ｄ上から反射光成分Ｌ２のみを検出する結
果となるわけである。図６に本実施例における演算後の
信号出力の関係を示す。図６を見てわかるように、色ト
ナーが中間転写ベルト５ｄ表面上に多く付着すればする
ほど受光信号が小さくなり、Ｋトナーの場合とほぼ同一
な曲線を描いている。すなはち、特に増幅器を用いてＫ
トナーと色トナーで増幅率を変えずとも充分なＳ／Ｎ比
が確保でき、精度良く画像濃度制御が実施可能となる。When forming the color toner patch Tc, a plurality of patches Tck when the K toner is present on the base and Tcn when the K toner is not present are formed under the same conditions except for the presence or absence of the K toner base, as in the first embodiment. And image density control for Tcn and image density control for Tck are executed. Then, the light receiving signal output of Tck becomes an output of only the reflected light L3 from the color toner portion due to the K toner background effect, and Tck
The light reception signal of cn is the reflected light L2 from the intermediate transfer belt 5d.
And the reflected light L3 from the color toner portion. A signal obtained by subtracting the output of the light receiving signal of Tck from the output of the light receiving signal of Tcn is used as the signal of the patch Tc. By doing so, the reflected light component L3 from the color toner portion is canceled, and as a result, only the reflected light component L2 is detected from the intermediate transfer belt 5d as in the case of the K toner. FIG. 6 shows the relationship between the signal outputs after the calculation in this embodiment. As can be seen from FIG. 6, the more the color toner adheres to the surface of the intermediate transfer belt 5d, the smaller the light receiving signal becomes, and the curve is almost the same as that of the K toner. That is, in particular, K
A sufficient S / N ratio can be secured without changing the amplification factor between toner and color toner, and image density control can be performed with high accuracy.
【００３５】以上、全実施例を中間転写ベルト方式を採
用した場合を記したが、中間転写ドラムを採用した場合
でも同様である。また、多重現像方式を採用して感光体
上で画像濃度制御を実施した場合でも同様の効果が得ら
れる。もちろん、静電転写体方式で静電転写ベルトや静
電転写ドラム上で実施しても同様な効果が得られるのは
言うまでもない。As described above, all the embodiments have described the case where the intermediate transfer belt system is employed, but the same applies to the case where the intermediate transfer drum is employed. The same effect can be obtained even when the image density control is performed on the photoreceptor by employing the multiple development method. Of course, it goes without saying that the same effect can be obtained even when the present invention is carried out on an electrostatic transfer belt or an electrostatic transfer drum by the electrostatic transfer body method.
【００３６】[0036]
【発明の効果】以上説明したように、本発明によれば、
色トナーの濃度検知を実施する際、下地にＫトナー層を
敷く。そうすると、受光素子で検知される反射光は色ト
ナーによる反射成分のみとなり、正確に濃度を検知でき
る。As described above, according to the present invention,
When detecting the density of the color toner, a K toner layer is laid on the base. Then, the reflected light detected by the light receiving element is only the reflected component by the color toner, and the density can be accurately detected.
【００３７】この場合、受光素子に入射する反射光はＫ
トナー検知時と比較して弱いため、増幅器によって信号
増幅してやると、より検知精度が上がる。In this case, the reflected light incident on the light receiving element is K
Since the signal is weaker than that at the time of toner detection, if the signal is amplified by an amplifier, the detection accuracy is further improved.
【００３８】また、下地にＫトナーを敷かない場合にお
ける反射光の受光信号と敷いた場合における反射光の受
光信号の差分を求めて、色トナーによる反射成分を取り
除くようにしても検知精度が高くなる。The detection accuracy is high even if the difference between the received light signal of the reflected light when the K toner is not laid on the base and the received light signal of the reflected light when the K toner is laid to remove the reflection component due to the color toner is high. Become.
【図１】 実施例１におけるカラー画像形成装置断面図FIG. 1 is a cross-sectional view of a color image forming apparatus according to a first embodiment.
【図２】 実施例１における濃度センサでトナー付着量
を測定する際の模式図FIG. 2 is a schematic diagram when measuring a toner adhesion amount by a density sensor according to the first embodiment.
【図３】 実施例１における受光量と色トナー付着量の
関係FIG. 3 shows the relationship between the amount of received light and the amount of attached color toner in the first embodiment.
【図４】 本発明の実施例２におけるカラー画像形成装
置断面図FIG. 4 is a sectional view of a color image forming apparatus according to a second embodiment of the present invention.
【図５】 実施例１における受光量とトナー付着量の関
係FIG. 5 is a diagram illustrating a relationship between a light receiving amount and a toner adhesion amount according to the first exemplary embodiment.
【図６】 実施例３における受光量と色トナー付着量の
関係FIG. 6 shows the relationship between the amount of received light and the amount of attached color toner in the third embodiment.
【図７】 濃度センサでトナー付着量を測定する際の模
式図FIG. 7 is a schematic diagram when measuring a toner adhesion amount with a density sensor.
【図８】 受光量とＫトナー付着量の関係FIG. 8 shows the relationship between the amount of received light and the amount of K toner attached.
【図９】 従来方法での受光量と色トナー付着量の関係FIG. 9 shows the relationship between the amount of received light and the amount of attached color toner in the conventional method.
【図１０】 従来方法で濃度センサで色トナー付着量を
測定する際の模式図FIG. 10 is a schematic view when measuring the amount of attached color toner with a density sensor by a conventional method.
【図１１】 従来方法で濃度センサで色トナー付着量を
測定する際の模式図FIG. 11 is a schematic diagram showing a conventional method for measuring the amount of attached color toner with a density sensor.
１ 感光ドラム ２ 接触方式ローラ帯電器 ３ 現像器支持体 ４ 現像器 ５ 中間転写ベルトユニット ６ 一次転写ローラ ７ 二次転写ローラ ８ 中間転写ベルトクリーニング用帯電装置 ９ 定着装置 １０ 感光ドラムクリーニング装置 １１ 露光装置 １２ 濃度センサ Ｌ 光路 REFERENCE SIGNS LIST 1 photosensitive drum 2 contact roller charger 3 developing device support 4 developing device 5 intermediate transfer belt unit 6 primary transfer roller 7 secondary transfer roller 8 charging device for intermediate transfer belt cleaning 9 fixing device 10 photosensitive drum cleaning device 11 exposure device 12 Density sensor L Optical path
フロントページの続き Ｆターム(参考） 2G059 AA01 EE02 GG02 HH02 KK01 MM09 2H027 DA09 DE02 DE07 DE10 EB04 EC19 EF01 2H030 AD01 BB02 BB24 BB36 BB42 BB63 2H077 BA10 DA03 DA04 DA05 DA31 DA63 DA82 GA13 Continued on the front page F-term (reference) 2G059 AA01 EE02 GG02 HH02 KK01 MM09 2H027 DA09 DE02 DE07 DE10 EB04 EC19 EF01 2H030 AD01 BB02 BB24 BB36 BB42 BB63 2H077 BA10 DA03 DA04 DA05 DA31 DA63 DA82 GA13
Claims (4)
射し、受光手段によりその反射光を受光してトナー像濃
度を検知するカラー画像形成装置において、反射率の高
いトナーの濃度を測定する場合には、まず反射率の低い
トナーの下地を形成した後、下地の上に反射率の高いト
ナーの像を形成して濃度検知を実行するカラー画像形成
装置。1. A color image forming apparatus which irradiates a toner image portion with light by a light irradiating unit and receives the reflected light by a light receiving unit to detect the toner image density, and measures the density of the toner having a high reflectance. In such a case, a color image forming apparatus that first forms a base of a toner with a low reflectance and then forms an image of a toner with a high reflectance on the base to perform density detection.
ナーであり、黒トナー下地の上に形成される反射率の高
いトナーとは黒以外の色トナーであることを特徴とする
請求項１記載のカラー画像形成装置。2. The toner according to claim 1, wherein the low-reflectivity toner serving as a base is black toner, and the high-reflectivity toner formed on the black toner base is a color toner other than black. 2. The color image forming apparatus according to 1.
受光手段の信号を増幅する手段を有し、検知するトナー
によって受光信号の増幅幅を可変することを特徴とする
請求項１に記載のカラー画像形成装置。3. The color image forming apparatus according to claim 1, wherein the color image forming apparatus includes a unit for amplifying a signal of the light receiving unit, and varies an amplification width of the light receiving signal depending on a toner to be detected. Forming equipment.
率の高いトナーの濃度を測定する際、反射率の低いトナ
ーによる下地を形成した場合に加え、下地を形成しない
場合も測定し、両者の測定結果の差分より反射率の高い
トナーの濃度を検知することを特徴とする請求項１に記
載のカラー画像形成装置。4. In the color image forming apparatus, when measuring the density of a toner having a high reflectivity, in addition to the case where a base is formed by a toner having a low reflectivity, the measurement is also performed when the base is not formed. 2. The color image forming apparatus according to claim 1, wherein a density of the toner having a high reflectance is detected from a difference between the results.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001172576A JP4467835B2 (en) | 2001-06-07 | 2001-06-07 | Color image forming apparatus |
| US10/161,709 US6775489B2 (en) | 2001-06-07 | 2002-06-05 | Image forming apparatus capable of detecting density of toner image |
| EP02012615A EP1267215B1 (en) | 2001-06-07 | 2002-06-06 | Image forming apparatus for controlling the image density of a toner image |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001172576A JP4467835B2 (en) | 2001-06-07 | 2001-06-07 | Color image forming apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2002365872A true JP2002365872A (en) | 2002-12-18 |
| JP4467835B2 JP4467835B2 (en) | 2010-05-26 |
Family
ID=19014177
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001172576A Expired - Fee Related JP4467835B2 (en) | 2001-06-07 | 2001-06-07 | Color image forming apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4467835B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003050493A (en) * | 2001-08-06 | 2003-02-21 | Canon Inc | Image forming device |
-
2001
- 2001-06-07 JP JP2001172576A patent/JP4467835B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003050493A (en) * | 2001-08-06 | 2003-02-21 | Canon Inc | Image forming device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4467835B2 (en) | 2010-05-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5236084B2 (en) | Image forming apparatus | |
| JP2006251686A (en) | Image forming apparatus | |
| JP2011028160A (en) | Image forming device | |
| US6775489B2 (en) | Image forming apparatus capable of detecting density of toner image | |
| JP4794226B2 (en) | Image forming apparatus | |
| US6512898B2 (en) | Image forming apparatus for detecting the density of toner | |
| JP2001194843A (en) | Image forming device | |
| JP5627549B2 (en) | Image forming apparatus | |
| JP2002072589A (en) | Image-forming device, and device and method for measuring toner quantity | |
| JP6536904B2 (en) | Image forming device | |
| JP2016126253A (en) | Image forming apparatus | |
| JP2001194851A (en) | Color image forming device | |
| JP4467835B2 (en) | Color image forming apparatus | |
| JP2011107613A (en) | Image forming apparatus and processing program | |
| JP4343079B2 (en) | Image forming apparatus | |
| JPH09247459A (en) | Image forming device | |
| JP2006220811A (en) | Toner amount measuring device and image forming apparatus having the same | |
| JP7467091B2 (en) | Image forming device | |
| JP3659015B2 (en) | Density measuring apparatus and image forming apparatus using the same | |
| JP4750897B2 (en) | Image forming apparatus | |
| JP3412385B2 (en) | Image forming device | |
| JP3172170B2 (en) | Image forming device | |
| JP2002040726A (en) | Image forming device | |
| JP2007003688A (en) | Image forming apparatus | |
| JP2003084508A (en) | Image forming apparatus |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| RD01 | Notification of change of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7421 Effective date: 20051214 |
|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20080604 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20091215 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20100129 |
|
| RD04 | Notification of resignation of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7424 Effective date: 20100201 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20100223 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20100224 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130305 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140305 Year of fee payment: 4 |
|
| LAPS | Cancellation because of no payment of annual fees |