CN104614962A - Image forming device - Google Patents

Abstract

High-concentration regions of low-reflectivity block images are accurately detected. An image forming device for detecting concentration of the block images by irradiating light from a laser oscillator (701) and using a line sensor (704) to receive reflected light reflected from the block images exists. By difference between the position of reflected light from a yellow block image (730) and the position of reflected light, which is transferred in a manner that the yellow block image (730) is overlapped to the top of a black block image (720), from the overlapped block images, concentration of the black block image (720) with low reflectivity is detected.

Description

Image processing system

The divisional application that the application is the applying date is on Dec 26th, 2009, application number is 200980163053.2, denomination of invention is the application for a patent for invention of " image processing system ".

Technical field

The present invention relates to electrofax or the electrostatic recording image processing system of such as duplicating machine, laser printer or facsimile recorder, relate more specifically to toner amount and measure and image color control.

Background technology

Usually, electrofax or electrostatic recording full-color image forming apparatus form image by use four kinds of colors i.e. yellow, magenta, cyan and black, and main two kinds of following methods are known.

A kind of is the image processing system of four round-robin methods with a photosensitive-member and multiple developing cell.In the method, on a photosensitive-member, electrostatic latent image is formed successively according to image information.These electrostatic latent images are developed by using the toner image of multiple color, and, the toner image of respective color is transferred on intermediate transfer belt successively, these toner images are transferred to recording sheet again from intermediate transfer belt, or are directly transferred on recording chart in the mode that toner image superposes mutually.Thus, coloured image is formed.

Another kind is the image processing system of the Cascading Methods often kind of color to a photosensitive-member and a developing cell.In the method, electrostatic latent image is formed according on the corresponding photosensitive-member of image information in image processing system.These electrostatic latent images are developed by using the toner image corresponding with respective color, and, these toner images are transferred on intermediate transfer belt successively, these toner images are transferred to recording chart again from these intermediate transfer belts, or are directly transferred on recording chart in the mode that toner image superposes mutually.Thus, coloured image is formed.

In above image processing system, in order to control the concentration of the image that will be formed, being controlled for the image forming conditions forming electrostatic latent image on photosensitive-member of such as exposure, developing bias and charged electric potential.But, even if these image forming conditions are identical, the concentration of the image that be formed is also because the various amounts (comprising the charge volume of toner, the sensitivity of photosensitive-member and transfer efficiency) of the state of such as image processing system change with the impact of the change of the environmental baseline of such as temperature and humidity over time.

Therefore, conventionally, the concentration of the toner image be transferred on photosensitive-member or intermediate transfer belt is detected, and, based on the image forming conditions of testing result FEEDBACK CONTROL such as charged electric potential, exposure and developing bias.

Such as, existence is used up and is irradiated block (patch) image and the method (see such as PTL 1) detecting the concentration of tile images based on the light quantity reflected from tile images (reflection light quantity).

Exist and use up the measurement of concetration toner image that is radiated at and photosensitive-member or intermediate transfer belt carry and based on the other method receiving the height measuring toner image from the light receiving position on the line sensor of the reflected light of toner image.Here, the concentration of toner image is higher, and the toner amount (amount of the toner of adhesion) for the formation of described toner image is more, and therefore the height of toner image is larger.Further, concentration is lower, and the toner amount (amount of the toner of adhesion) for the formation of toner image is fewer, and therefore the height of toner image is lower.Therefore, the height of the toner image measured based on the light receiving position on line sensor is converted into concentration (see such as PTL 2) as the amount of toner adhered to.

Quoted passage list

Patent documentation

PTL 1: Japanese Patent Publication No.2003-76129

PTL 2: Japanese Patent Publication No.4-156479

Summary of the invention

Technical matters

But in the invention described in PTL 1, there is so a kind of problem, that is, because the amount of reflected light from the black tile images with low reflectivity is few, therefore the SN of reflected light is than low, and can not realize the high precision test of concentration.

Further, in PTL 2, also there is so a kind of problem, that is, be difficult to the light receiving position of high accuracy detection antiradar reflectivity block image and the high precision test of concentration can not be realized.

More specifically, the black tile images with the antiradar reflectivity caused due to optical absorption characteristics encounters problems, and particularly, the amount from the reflected light of this tile images reduces along with the increase of concentration, and is difficult to the concentration detecting this tile images.

Further, cyan tile images also encounters problems: according to the wavelength of the light from light source irradiation, reflectivity is low, and can not receive the reflected light of q.s, makes thus to be difficult to the accuracy detection concentration with high.

Therefore, the object of the invention is, the image processing system of the concentration that accurately can detect the high concentration tile images even formed by antiradar reflectivity toner is provided.

The solution of problem

In order to solve above problem, image processing system according to claim 1 comprises: the image for the formation of the toner image of the benchmark toner image and superposition with the first color forms assembly, in the toner image of described superposition, the top of toner image with the second low color of luminance factor first color superposes the toner image of the first color, and the toner image of the first color is specifying to be formed under the predetermined condition about the toner height of benchmark toner image; Be carried through the image bearing member that image forms the benchmark toner image of assembly formation and the toner image of superposition; For light shining the illumination module of the toner image being carried on benchmark toner image on image bearing member and superposition; Irradiate and the light-receiving module of the light reflected from benchmark toner image and the light from illumination module irradiation and from the toner image reflection of superposition from illumination module for receiving; And, the toner concentration detection components of the toner concentration of the toner image with the second color is detected for the difference between the light receiving position and the light receiving position of the light reflected from the toner image superposed of the light from the reflection of benchmark toner image detected by light-receiving module.

Beneficial effect of the present invention

According to the present invention, the concentration of the high concentration tile images even formed by antiradar reflectivity toner accurately can be detected.

Accompanying drawing explanation

Fig. 1 is the schematic sectional view of the image processing system that the first embodiment is shown.

Fig. 2 is the diagram of the major part of the toner height sensor unit of the first embodiment.

Fig. 3 is the diagram that the light intensity of the tile images illustrated for measuring from the toner height sensor unit by the first embodiment detects the operation of light receiving position.

Fig. 4 comprises the diagram of the corresponding relation between the amount of toner and concentration that corresponding relation between light receiving position difference and the amount of toner adhered to and adhesion are shown.

Fig. 5 comprises the diagram of the light intensity that the light that the tile images from respective color measured by the toner height sensor unit of the first embodiment is reflected is shown.

Fig. 6 comprises the diagram of the spectral distribution that yellow, magenta, cyan and black are shown.

Fig. 7 comprises the diagram of operation when illustrating that the image processing system of the first embodiment forms the toner image of superposition.

Fig. 8 is diagram measurement illumination being mapped to the major part of the toner height sensor unit of the toner image of superposition.

Fig. 9 is the diagram of the light intensity of the toner image that the superposition of being measured by the toner height sensor unit of the first embodiment is shown.

Figure 10 is the control block diagram of the image processing system of the first embodiment.

Figure 11 is the process flow diagram controlled for the concentration controlling image forming conditions that the first embodiment is shown.

Figure 12 is the diagram of the tile images of carrying on intermediate transfer belt 51.

Figure 13 comprises the diagram that printer unit output characteristics and look-up table are shown.

Figure 14 comprises the diagram of operation when illustrating that the image processing system of the second embodiment forms the toner image of superposition.

Figure 15 is the schematic sectional view of the image processing system that the 3rd embodiment is shown.

Figure 16 is the schematic sectional view of the image processing system that the 4th embodiment is shown.

Embodiment

(the first embodiment)

Fig. 1 illustrates the image processing system used in the present embodiment of the reader unit 100A at the top comprising printer unit 100B and be installed on printer unit 100B.

Reader unit 100A comprises the contribution glass platform 81 of placement original copy 80, the exposure lamp 82 scanning the image of the original copy 80 be positioned on contribution glass platform and the picture sweep unit 85 formed by catoptron.The reflected light of the original copy 80 be irradiated by light by using exposure lamp 82 is converged by short focal length lens array 83, be read by the panchromatic sensor 84 of such as CCD, and by using graphics processing unit 108 to be converted into the picture signal corresponding with respective color.

Printer unit 100B comprises the photosensitive drums 1 being driven to and rotating along arrow A direction.Charger 2, exposure device 3, developing apparatus 4, transfer device 5, drum clearer 6 etc. are arranged in around photosensitive drums 1 along the sense of rotation of photosensitive drums 1 successively, and these devices are used as image in the lump and form assembly.

Charger 2 is the corona charging devices (coronacharger) making photosensitive drums 1 charge in a non-contact manner.Also by use such as conduct electricity charging roller or charging brush or magnetic brush be set to contact with photosensitive drums 1 or close contact charging device realizes charger 2.

The exposure device 3 light E of the exposure corresponding with image information irradiates the photosensitive drums 1 through charging, to form electrostatic latent image.In the present embodiment, the image of original copy 80 stands to the four kinds of colors i.e. color separated of yellow, cyan, magenta and black, and, photosensitive drum surface forms the electrostatic latent image corresponding with respective color successively.

Developing apparatus 4 is configured to developing cell 4Y, 4M, 4C and 4K of being rotated the developer holding yellow, magenta, cyan and black by use rotary unit along arrow B direction.Here, developing cell 4Y holds yellow developer, and developing cell 4M holds the developer of magenta, and developing cell 4C holds the developer of cyan, and developing cell 4K holds the developer of black.When developing electrostatic latent image, the developing cell being used in the color of development moves to the developing location on the surface close to photosensitive drums 1, and electrostatic latent image is visualized as toner image.

Transfer device 5 comprises as the intermediate transfer belt 51 being driven to the annular image load bearing component rotated along arrow C direction, primary transfer roller 53, secondary transfer printing opposed roller 56 and secondary transfer roller 57.Primary transfer roller 53 is pressed against photosensitive drums 1 by the intermediate transfer belt 51 between primary transfer roller 53 and photosensitive drums 1, to form primary transfer nip portion, and, secondary transfer roller 57 is pressed against secondary transfer printing opposed roller 56, to form secondary transfer nip by the intermediate transfer belt 51 between secondary transfer roller 57 and secondary transfer printing opposed roller 56.

Further, intermediate transfer belt 51 is equipped with removal and is not transferred on recording materials P and the band clearer 55 residuing in the toner on intermediate transfer belt 51.

Drum clearer 6 is configured to the toner surface by the cleaning doctor be made up of polyurethane (urethane) rubber etc. being pressed against photosensitive drums 1 removed in photosensitive drums 1.

Except above device, printer unit 100B also comprises printer control module 109 described below, holds the paper feed cassette 7 of recording materials P, from transfer printing above secondary transfer nip is transmitted the recording materials P of toner image conveyer belt 58 and by the fixing device 9 of toner image in recording materials P.

Further, be mapped to be needed on tile images on intermediate transfer belt 51 and the toner height sensor unit 21 detecting the amount (toner height) of the thickness direction of tile images based on the position received on the sensor of reflected light is set to the device of the concentration measuring toner image by measuring illumination.The toner height detected by toner height sensor unit 21 is converted into concentration by process described below.

Below, by the operation of the image processing system in description the present embodiment.

The surface of photosensitive drums 1 is by charger 2 uniform charging.Subsequently, when the light E of the exposure of the image signal modulation according to the yellow color component exported from reader unit 100A is transmitted into photosensitive drums 1 by catoptron by exposure device 3, the surface of photosensitive drums 1 forms the electrostatic latent image corresponding with the image of the yellow color component in original copy 80.

Subsequently, when developing apparatus 4 rotates along arrow B direction, the developing cell 4Y that the electrostatic latent image corresponding with the image of the yellow color component formed on the photosensitive drum 1 is moved to developing location develops for yellow toner image.

Subsequently, when yellow toner image according to photosensitive drums 1 along arrow A direction rotate into primary transfer nip portion time, apply primary transfer voltage from primary transfer roller 53, and Yellow toner is transferred on intermediate transfer belt 51.The remaining toner in the photosensitive drums 1 be not transferred on intermediate transfer belt 51 is removed by drum clearer 6.

Subsequently, the surface of photosensitive drums 1 is by charger 2 uniform charging.Subsequently, when the light E of the exposure of the image signal modulation according to the magenta component exported from reader unit 100A is transmitted into photosensitive drums 1 by exposure device 3, the surface of photosensitive drums 1 forms the electrostatic latent image corresponding with the image of the magenta component in original copy 80.

Subsequently, when developing apparatus 4 rotates along arrow B direction, the developing cell 4M that the electrostatic latent image corresponding with the image of the magenta component formed on the photosensitive drum 1 is moved to developing location develops for magenta toner image.

Subsequently, when yellow toner image response intermediate transfer belt 51 enters primary transfer nip portion again along the rotation in arrow C direction, apply primary transfer voltage from primary transfer roller 53, and, magenta toner image is transferred, to be superimposed upon on the top of yellow toner image.

Similarly, cyan toner image and black toner image are formed successively on the photosensitive drum 1, and are transferred mutually superpose at primary transfer nip portion place successively.Therefore, intermediate transfer belt 51 forms full-color toner image.

Here, before the toner image by mutually superposing each color on intermediate transfer belt 51 successively forms full-color toner image, secondary transfer printing voltage is not applied to secondary transfer printing opposed roller 56 and secondary transfer roller 57.Therefore, before acquisition full-color toner image, carrying on intermediate transfer belt 51 is also continued to be carried on intermediate transfer belt 51 by the toner image that intermediate transfer belt 51 transmits.Further, the position of clearer 55 is with known configuration away from intermediate transfer belt 51.Therefore, before toner image is transferred on recording materials P completely, do not removed the toner image of each color be transferred on intermediate transfer belt 51 by band clearer 55.

The full-color toner image that intermediate transfer belt 51 is formed is transferred to secondary transfer nip according to intermediate transfer belt 51 along the rotation in arrow C direction.

Further, recording materials P is stored in paper feed cassette 7, and by making paper using feed roller 71 and 72 be fed to one by one, and be transferred to alignment roller 73.The recording materials P being transferred to alignment roller 73 is adjusted in time, and is passed to secondary transfer nip to contact with full-color toner image.

When the full-color toner image on intermediate transfer belt 51 and recording materials P enter two transfer printing nip portion, transfer voltage is applied to secondary transfer roller 57, and the full-color toner image on intermediate transfer belt 51 is transferred on recording materials P.Not to be transferred on recording materials P and the toner residued on intermediate transfer belt 51 is removed by band clearer 55.

The recording materials P of carrying toner image is transferred to fixing device 9 by conveyer belt 58, and, to be held between fixing roller 91 and 92 and to be heated by well heater (not shown) while being transmitted by fixing roller 91 and 92, toner image is fixed on recording materials P.

Then, the recording materials P of fixing above toner image is discharged to paper discharge tray 75 by paper distributing roller 74.

Below, the detection of the concentration of the toner image performed by image processing system will be described.

Photosensitive drums 1 is charged by charger 2, and, form the electrostatic latent image corresponding with each color component i.e. tile images of yellow, magenta, cyan and black by using exposure device 3.

The electrostatic latent image of the tile images of the respective color component formed on the photosensitive drum 1 is developed tile images into corresponding color component by using developing apparatus 4.

Subsequently, when the tile images of each color component is transferred to primary transfer nip portion according to photosensitive drums 1 along the rotation in arrow A direction, apply primary transfer voltage from primary transfer roller 53, and the tile images of color component is transferred on intermediate transfer belt 51.When the tile images being carried on each color component on intermediate transfer belt 51 to be transferred to by toner height sensor unit 21 to measure light-struck position (irradiation position) according to intermediate transfer belt 51 along the rotation in arrow C direction, measure the light receiving position corresponding with the toner height of tile images.The light receiving position of the tile images measured by this way is converted into concentration by process described below.

Below, by by use Fig. 2 ~ 4, the image processing system 100 described in more detail in Fig. 1 passes through the method using toner height sensor unit 21 from the toner height detection concentration of yellow tile images 710.

Fig. 2 is the diagram of the major part of the toner height sensor unit 21 of the present embodiment.

Toner height sensor unit 21 is configured with as the laser oscillator 701 of illumination module, convergent lens 702, sensitive lens 703 and the line sensor 704 being used as light-receiving module.

Laser oscillator 701 is irradiated to measuring light (wavelength of 780 [nm]) on intermediate transfer belt 51 to provide the spot diameter of 50 [μm] by convergent lens 702.

Line sensor 704 is configured such that multiple photo detector is arranged and embarks on journey.Further, each in the photo detector of the line sensor 704 of the present embodiment is configured to export the voltage corresponding with light intensity during reception light.

Below, the method using the toner height sensor unit 21 in Fig. 2 to detect the light receiving position of tile images 710 will be described through.

As represented in dotted line, before yellow tile images 710 is transferred to irradiation position, the measurement light irradiated from laser oscillator 701 is reflected from the surface of intermediate transfer belt 51, and reflected light (dotted line G) is focused on line sensor 704 by sensitive lens 703.In this case, the reflected light that can not incide on sensitive lens 703 is configured to be stopped by baffle plate (not shown).Note, dotted line G represents the light from the center through sensitive lens 703 in the reflected light of intermediate transfer belt 51.

Subsequently, as shown by the solid line, when yellow tile images 710 is transferred to irradiation position, measure light and reflected from the surface of tile images 710, and reflected light (solid line N) is focused on line sensor 704 by sensitive lens 703.Note, solid line N represents the light from the center through sensitive lens 703 in the reflected light of tile images 710.

In this case, the position be focused on line sensor 704 from the reflected light (solid line N) of tile images 710 is different from the position that the reflected light (dotted line G) from intermediate transfer belt 51 is focused.

Pitch between photo detector can be designed so that: even if when tile images changes the amount corresponding with a toner particle with mean particle diameter, also can detect the change of light receiving position from the reflected light from tile images.

Further, in the present embodiment, line sensor 704 is used as light-receiving module.But, also can use the area sensor of the photo detector with two-dimensional arrangement.

Further, the position relationship between laser oscillator 701 and line sensor 704 is not limited to the position relationship in the present embodiment.The configuration of multiple photo detectors of the direction deployment line sensor 704 changed along the light receiving position from the reflected light of tile images when can use the toner Level Change when tile images.

More preferably, line sensor 704 is positioned at the position that line sensor 704 does not receive the specular components (specular reflection component) of the reflected light on the surface from intermediate transfer belt 51 or the surface from tile images.In this case, any position relationship can be used.

If the reflectivity forming the luminance factor intermediate transfer belt 51 of the toner of tile images is high, the amount so from the reflected light of tile images increases along with the increase of the concentration of tile images.Therefore, described concentration becomes higher, then more accurately can detect light receiving position.

Fig. 3 illustrates the light intensity D (0) of light of the surface reflection from intermediate transfer belt 51 and the light intensity D (1) from the light of the surface reflection of yellow tile images 710 that are measured by the line sensor 704 in Fig. 2.

In the present embodiment, from the light receiving position of the reflected light of intermediate transfer belt 51 be the position P (0) of the reflection light quantity maximum from intermediate transfer belt 51 on line sensor 704.Further, from the light receiving position of the reflected light of yellow tile images 710 be the position P (1) of the reflection light quantity maximum from yellow tile images 710 on line sensor 704.

Position from intermediate transfer belt 51 reflection measurement light and the position from tile images 710 reflection measurement light differ the amount corresponding with the toner height of tile images 710.Therefore, the difference (light receiving position difference Δ P (1)) between the light receiving position P (0) of the intermediate transfer belt 51 and light receiving position P (1) of tile images 710 increases pro rata with the toner height of tile images 710.

By using the table of the corresponding relation between the expression light receiving position difference described and the amount of the toner adhered to below, light receiving position difference Δ P (1) corresponding with the toner height of tile images 710 is detected as the amount of the toner of adhesion.Light receiving position difference Δ P (1) is calculated by use formula 1.

Δ P (1)=P (1)-P (0) ... (formula 1)

Fig. 4 (a) is the diagram of data that representative represents the table of the corresponding relation between light receiving position difference and the amount of toner adhered to, and Fig. 4 (b) is the diagram that representative represents the data of the table of the corresponding relation between the amount of the toner adhered to and the concentration of yellow tile images 710.

The amount of the concentration of tile images 710 and the toner of adhesion is proportional, and, by referring to the table (Fig. 4 (b)) of the corresponding relation represented between the amount of the toner adhered to and concentration, the amount based on the toner of the adhesion of the tile images 710 of light receiving position difference detection from the above description detects the concentration of tile images 710.Because the amount of the toner of the adhesion of tile images is different between color component from the corresponding relation between concentration, therefore, each color component is provided to the table of the corresponding relation between amount and concentration representing the toner adhered to.

In the present embodiment, light receiving position P (0) and P (1) are the positions of the photo detector on the line sensor 704 of the reflection light quantity from intermediate transfer belt 51 and the reflection light quantity maximum from tile images 710.But, also can use other configuration any.By using the light intensity D (0) and D (1) application curves matching that utilize the least squares approach of Gaussian function to measure the output from line sensor 704, further, the position determined by the arithmetical operation of predictability from the parameter of the Gaussian function after matching can be used as light receiving position.As shown in Equation 2, Gaussian function is take A as maximal value, the function with bell peak centered by x=μ, and here, μ represents light receiving position.

[mathematical expression 1]

$f\left(x\right)=\frac{A}{\sqrt{{2\mathrm{\π\σ}}^2}}\exp \{-\frac{{(x-\mathrm{\μ})}^2}{{2\mathrm{\σ}}^2}\}+C$ (formula 2)

Further, the matching for such as Lorentz functional expression (3) and quadratic function (formula 4) can also be used.

[mathematical expression 2]

$f\left(x\right)=\frac{2A}{\mathrm{\π}}\·\frac{w}{4{(x-x_C)}^2+w^2}+C$ (formula 3)

F (x)=A (x-B) ²+ C ... (formula 4)

Fig. 5 (a) ~ 5 (d) is the diagram illustrated from the light intensity of the light of yellow, magenta, cyan and black tile images reflection and the light intensity from the light of intermediate transfer belt 51 reflection.

Fig. 5 (a) illustrates the light receiving position P (0) from light receiving position P (Y1), the P (Y2) of light of the yellow tile images Y1 with different concentration, Y2, Y3 and Y4 reflection, P (Y3) and P (Y4) and the light from intermediate transfer belt 51 reflection.The concentration of yellow tile images meets Y1<Y2<Y3<Y4.

Further, Fig. 5 (b) illustrates the light receiving position P (0) from light receiving position P (M1), the P (M2) of light of the magenta tile images M1 with different concentration, M2, M3 and M4 reflection, P (M3) and P (M4) and the light from intermediate transfer belt 51 reflection.The concentration of magenta tile images meets M1<M2<M3<M4.

Further, Fig. 5 (c) illustrates the light receiving position P (0) from light receiving position P (C1), the P (C2) of light of the cyan tile images C1 with different concentration, C2, C3 and C4 reflection, P (C3) and P (C4) and the light from intermediate transfer belt 51 reflection.The concentration of cyan tile images meets C1<C2<C3<C4.

As shown in Fig. 5 (a) ~ 5 (c), can find out, in yellow, magenta and cyan tile images, along with concentration increases, light receiving position difference also increases.

On the contrary, Fig. 5 (d) illustrates the light receiving position P (0) from light receiving position P (K1), the P (K2) of light of the black tile images K1 with different concentration, K2, K3 and K4 reflection, P (K3) and P (K4) and the light from intermediate transfer belt 51 reflection.The concentration of black tile images has relation K1<K2<K3<K4.

In black tile images, due to the absorbing properties of black toner, therefore, the amount of reflected light is few, and, be difficult to accurately detect light receiving position.Especially, in high concentration black tile images, because the amount of toner that adheres to and concentration increase pro rata, therefore, the amount from the reflected light of tile images reduces, and therefore, accurately can not detect light receiving position.

By this way, due to the low reflectivity of the black tile images of the wavelength (780 [nm]) about the measurement light irradiated from toner height sensor unit 21, therefore, the amount from the reflected light of black tile images is few.

Fig. 6 (a) ~ 6 (d) illustrates the spectral distribution of yellow, magenta, cyan and black toner respectively.Be about 90 [%] (Fig. 6 (a), Fig. 6 (b)) about the reflectivity of the measurement light used in the present embodiment (wavelength of 780 [nm]) for yellow and magenta toner, being about 50 [%] (Fig. 6 (c)) for cyan toner, is about 10 [%] (Fig. 6 (d)) for black toner.

Therefore, in the present embodiment, from as have the first color benchmark toner image yellow tile images reflected light light receiving position and from the reflected light of intermediate transfer belt 51 light between light receiving position difference (light receiving position of yellow tile images is poor) be detected.Subsequently, the yellow tile images formed under the top of the tile images of the black as the second color is superimposed upon the image forming conditions identical with the image forming conditions of the yellow tile images detecting light receiving position, to form the toner image of superposition.Subsequently, detected from the light receiving position difference (light receiving position of the toner image superposed is poor) between the light receiving position of reflected light of the toner image of superposition and the light receiving position of the reflected light from intermediate transfer belt 51.Difference between the light receiving position difference and the light receiving position difference of the toner image superposed of yellow tile images, the light receiving position calculated between the light receiving position from the reflected light of black tile images and the light receiving position from the reflected light of intermediate transfer belt 51 is poor.

Because the measurement light irradiated is reflected from the yellow tile images the toner image of superposition, therefore, by the toner image superposing the superposition that yellow tile images is formed on the top of black tile images, there is large reflection light quantity, and its light receiving position also can be accurately detected.

Therefore, even if for the black tile images with low reflectivity, also by using above-mentioned method to detect the concentration of the amount of the toner adhered to or the amount conversion from the toner adhered to from the light receiving position difference of the black tile images calculated.

Below, by by using Fig. 7 ~ 9 to describe in detail for the toner image by using the toner height sensor unit 21 of the present embodiment superpose on the top of toner image with the second color to have the first color to form the method for the toner image superposed and to be used for detecting the method for light receiving position of toner image of superposition.In the description of Fig. 7 ~ 9, the toner image with the first color is yellow tile images 710, and the toner image with the second color is black tile images 720.Further, the toner image 730 of superposition is produced by superposing yellow tile images 710 on the top of black tile images 720.

Fig. 7 (a) ~ 7 (d) is the sectional view of the major part of the image processing system 100 of the present embodiment.

First, the black tile images 720 formed on the photosensitive drum 1 by developing cell 4K is transferred on intermediate transfer belt 51 at primary transfer nip portion place.Subsequently, black tile images 720 is transferred to the irradiation position (Fig. 7 (a)) of toner height sensor unit 21 along the rotation in arrow C direction according to intermediate transfer belt 51.Now, toner height sensor unit 21 does not irradiate to black tile images 720 and measures light.

When black tile images 720 is transferred to secondary transfer nip according to intermediate transfer belt 51 along the rotation in arrow C direction, do not apply secondary transfer printing voltage to secondary transfer roller 57 and secondary transfer printing opposed roller 56.Further, be with the position of clearer 55 with similar mode when forming full-color toner image away from intermediate transfer belt 51.Therefore, black tile images 720 is again transferred to primary transfer nip portion (Fig. 7 (b)) while maintenance toner height.

Subsequently, the yellow tile images 710 as the benchmark toner image with the first color is formed on the photosensitive drum 1 to be superimposed on intermediate transfer belt 51 carrying and in the black tile images 720 transmitted by intermediate transfer belt 51 (Fig. 7 (c)) by developing cell 4Y.

Subsequently, yellow tile images 710 is transferred to be superimposed on the top of black tile images 720 at primary transfer nip portion place, therefore, forms the toner image 730 (Fig. 7 (d)) of superposition.

Below by the method by using Fig. 8 description to be used for light receiving position difference P (3) of the toner image 730 detecting superposition.

In toner height sensor unit 21, when the toner image 730 superposed is positioned at the position be illustrated by the broken lines, intermediate transfer belt 51 is penetrated in laser oscillator 701 measurement illumination, further, the light reflected from intermediate transfer belt 51 focuses on the position P (0) on line sensor 704.In this case, the dotted line G in Fig. 8 represents the reflected light from the center through sensitive lens 703 light of the surface reflection of intermediate transfer belt 51.

Subsequently, when the toner image 730 superposed is transferred to along the rotation in arrow C direction the position represented by solid line according to intermediate transfer belt 51, the measurement light irradiated from laser oscillator 701 is reflected from the toner image 730 of superposition, further, this light focuses on position P (3) place on line sensor 704.In this case, the solid line H in Fig. 8 represents the reflected light at the center through sensitive lens 703 light reflected from the Yellow toner (yellow tile images 710) on the surface of the toner image 730 being used as superposition.

Fig. 9 illustrates the light intensity D (3) of the light intensity D (0) of the reflected light from intermediate transfer belt 51 measured by the toner height sensor unit 21 in Fig. 8 and the reflected light from the toner image 730 of superposition.

According to Fig. 9, the surface of the toner image 730 of superposition is corresponding with Yellow toner (yellow tile images 710), therefore, the light intensity D (3) of the light that can reflect according to the toner image 730 from superposition detects the light receiving position P (3) of the light reflected from the toner image 730 of superposition.

The toner height of toner image 730 of superposition equal the toner height of black tile images 720 and the toner height of yellow tile images 710 with.Namely, the light receiving position of the light reflected from yellow tile images 710 at the light receiving position of light of the surface reflection of the toner image 730 from superposition changes the light receiving position of the amount corresponding with the toner height of black tile images, measures poor Δ P (2) of light receiving position of black tile images.

Therefore, the light receiving position P (3) of the light that can reflect based on the toner image 730 from superposition, light receiving position difference Δ P (2) by use formula 5 and 6 calculating black tile images 720.

The light receiving position P (3) of light reflected according to the toner image from above-mentioned superposition and the light receiving position P (0) of the light from intermediate transfer belt 51 reflection, calculates light receiving position difference Δ P (3) of the light reflected from the toner image 730 of superposition by use formula 6.And, the light receiving position P (1) of light reflected according to the yellow tile images 710 from formation separately under single color state and the light receiving position P (0) of the light from intermediate transfer belt 51 reflection, calculates light receiving position difference Δ P (1) of the light reflected from yellow tile images 710 by use formula 1.Light receiving position difference Δ P (2) of black tile images 720 is that the light receiving position of the black tile images 720 of the formation indirect inspection of the toner image 730 by superposition is poor.

Δ P (2)=Δ P (3)-Δ P (1) ... (formula 5)

Δ P (3)=P (3)-P (0) ... (formula 6)

By use represent light receiving position difference and adhere to toner amount between corresponding relation Fig. 4 part (a) shown in table, based on light receiving position difference Δ P (2) of black tile images, detect the amount of the toner of the adhesion of black tile images 720.Further, the table of the corresponding relation between the amount of the toner adhered to by using representative and the concentration corresponding to black tile images, from the amount of the toner of the adhesion of black tile images 720, detects the concentration of black tile images 720.

Below, the concentration described in the present embodiment is controlled.

The image processing system of the present embodiment passes through by using the deep or light of 256 gray level grade (0 ~ 255) displaying chart pictures.Therefore, when by using tile images to realize concentration control, 16 tile images are formed for each color.With such as 15,31 ..., 239 and 255 16 ratings represent the concentration of 16 tile images.Below, 16 yellow tile images T (Ya), T (Yb) ... T (Yx) is collectively referred to as with T (Yp).About this point, a, b ... mean that concentration scale is 15 with p, 31 ... with 255.Similarly, magenta tile images T (Ma), T (Mb) ... be called as T (Mx) with T (Mp), cyan tile images T (Ca), T (Cb) ... T (Cx) is called as with T (Cp).Black tile images T (Ka), T (Kb) ... T (Kx) is called as with T (Kp).

Note, quantity and the concentration scale of tile images are appropriately determin, and are not limited to those in the present embodiment.

Here, Figure 10 is the control block diagram of the image processing system of the present embodiment.Further, Figure 11 is described through the process flow diagram using toner height sensor unit 21 to realize the operation of CPU when concentration controls, and in the present embodiment, described operation comprises the process of the concentration for detecting black tile images T (Kx).

In Fig. 10, CPU 128 is the control circuits controlling whole image processing system.ROM130 stores the control program for controlling the various process performed by image processing system.RAM132 by CPU 128 for performing the system working memory of process.

Further, the ROM 130 of the present embodiment or RAM 132 stores the image forming conditions for the formation of yellow, magenta, cyan and black toner image described below.Be stored in image forming conditions in ROM130 to control immediately preceding being used to concentration after the primary power connecting image processing system, and stored in advance when factory loads and transports.Further, be stored in image forming conditions in RAM 132 be used to after the primary power connecting image processing system second and concentration subsequently control, and each perform concentration control time be updated.

Measurement illumination is mapped on intermediate transfer belt 51 according to the signal from CPU 128 by laser oscillator 701.

When line sensor 704 receives the reflected light from intermediate transfer belt 51 and the reflected light from the tile images be carried on intermediate transfer belt 51, by using CPU 128, the position at the reflection light quantity place that the acquisition on the line sensor 704 measured by each photo detector is maximum is detected as light receiving position.

Operating unit 101 is arranged on the guidance panel in the main body of the image processing system 100 shown in Fig. 1, and be used by a user in the various conditions of input for the formation of image.User performs predetermined input by guidance panel, thus the signal being used for making toner height sensor unit 21 perform concentration control is outputted to CPU 128.Operating unit 101 can be the keyboard of the PC be connected with image processing system by network, and signal that concentration controls outputs to CPU 128 by being used for making toner height sensor unit 21 to perform can be configured to respond predetermined input.

When inputting from operating unit 101 for making toner height sensor unit 21 perform the signal of concentration control, CPU 128 performs the control shown in the process flow diagram of Figure 11.As an alternative, CPU 128 can be configured to image formed be performed predetermined number of times after perform Figure 11 process flow diagram shown in control, or the control that performs after the primary power connecting image processing system 100 (Fig. 1) shown in the process flow diagram of Figure 11 can be configured to.

The process of the program in ROM 130 by CPU 128 flowchart is stored in by reading.

Below, by by using the process flow diagram shown in the schematic sectional view of the image processing system in Fig. 1 and Figure 11, describing the concentration realized by the image processing system of the present embodiment in detail and controlling.

First, CPU 128 controls image processing system 100 and on intermediate transfer belt 51, forms yellow, magenta and cyan tile images T (Yx), T (Mx) and T (Cx) (S100) by using yellow, magenta and cyan image formation condition.

The tile images formed in the step s 100 shown in Figure 12 is transferred to the mode on intermediate transfer belt 51.On intermediate transfer belt 51, along the sense of rotation (arrow C direction) of intermediate transfer belt 51 with predetermined gap-forming tile images T (Yx), T (Mx) and T (Cx).Described predetermined interval is the distance larger than the spot diameter of the measurement light irradiated from laser oscillator 701.

Tile images T (Yx), T (Mx) that intermediate transfer belt 51 is formed and T (Cx) are sequentially transferred to the irradiation position of toner height sensor unit 21 along the rotation in arrow C direction according to intermediate transfer belt 51.

Subsequently, the CPU 128 light receiving position P (0) that makes toner height sensor unit 21 detect the light reflected from intermediate transfer belt 51 and light receiving position P (Yx), the P (Mx) of light that reflect from tile images T (Yx), T (Mx) and T (Cx) and P (Cx).

In step S101, CPU 128 makes laser oscillator 701 measurement illumination be mapped on intermediate transfer belt 51, and samples with the signal of predetermined cycle to the reflection light quantity exported from line sensor 704.

Therefore, CPU 128 two light intensity D (0) of light of measuring light intensity D (Yx), the D (Mx) of the light reflected from respective block image T (Yx), T (Mx) and T (Cx) and D (Cx) and each tile images being reflected from intermediate transfer belt 51.Subsequently, CPU 128 detects the light receiving position P (0) of intermediate transfer belt 51 and light receiving position P (Yx), the P (Mx) of tile images T (Yx), T (Mx) and T (Cx) and P (Cx) from light intensity D (0), D (Yx), D (Mx) and D (Cx) respectively by using above-mentioned method.

Here, the light receiving position P (0) in the present embodiment be along transmission direction with predetermined distance from the light receiving position of the intermediate transfer belt 51 of the front end of the transmission direction of a tile images and the mean value of light receiving position of intermediate transfer belt 51 of rear end of transmission direction leaving a tile images along the direction contrary with transmission direction with predetermined distance.That is, the equalization of the upstream side of transmission direction of tile images T (Yx), T (Mx) and T (Cx) and the light receiving position of the reflected light from intermediate transfer belt 51 in downstream alleviates the loose error caused by the change of the thickness of intermediate transfer belt 51 or intermediate transfer belt 51.

Subsequently, CPU 128 calculates light receiving position difference Δ P (Yx), Δ P (Mx) and Δ P (Cx) (S102) based on the light receiving position P (0) measured in step S101, P (Yx), P (Mx) and P (Cx) by use formula 7 ~ 9.

Δ P (Yx)=P (Yx)-P (0) (x=a, b ..., p) ... (formula 7)

Δ P (Mx)=P (Mx)-P (0) (x=a, b ..., p) ... (formula 8)

Δ P (Cx)=P (Cx)-P (0) (x=a, b ..., p) ... (formula 9)

Subsequently, CPU 128 determines light receiving position difference Δ P (Yx), whether Δ P (Mx) and Δ P (Cx) equals the desired value Δ P that is stored in advance in ROM 130 _i(Yx), Δ P _iand Δ P (Mx) _i(Cx) (S103).Here, term desired value be from have suitable concentration scale tile images detect light receiving position difference and be stored in advance ROM 130.

Here, CPU 128 can be configured to by using the table of the corresponding relation represented between light receiving position difference and the amount of toner adhered to detect amount Q (Yx), Q (Mx) and the Q (Cx) of the toner of the adhesion of respective block image from light receiving position difference Δ P (Yx), Δ P (Mx) and Δ P (Cx).Here, Q (Yx) is the amount of the toner of the adhesion of yellow tile images T (Yx), Q (Mx) is the amount of the toner of the adhesion of magenta tile images T (Mx), and Q (Cx) is the amount of the toner of the adhesion of cyan tile images T (Cx).

Further, the table that CPU 128 also can be configured in the amount of toner by using representative to adhere to and tile images T (Yx), T (Mx) and T (Cx) between the concentration of each corresponding relation detects the concentration of tile images T (Yx), T (Mx) and T (Cx).That is, CPU 128 and these tables are also used as toner concentration detection components.

If light receiving position difference Δ P (Yx), Δ P (Mx) and Δ P (Cx) are not equal to desired value Δ P in step s 103 _i(Yx), Δ P _iand Δ P (Mx) _i(Cx), so CPU 128 controls yellow, magenta and cyan image formation condition (S104).Here, image forming conditions is charging voltage, developing bias, primary transfer voltage and look-up table etc.Control and the existing concentration of image forming conditions control similar, and, omit the description that it is detailed.

In step S104, CPU 128 stores the yellow of change, magenta and cyan image formation condition in RAM 132, then proceeds to step S105.Therefore, by the light receiving position difference of the tile images using the image forming conditions be stored in RAM 132 to be formed, there is the value equaling desired value.

On the other hand, if poor Δ P (Yx) of the light receiving position of yellow, magenta and cyan tile images, Δ P (Mx) and Δ P (Cx) equal desired value Δ P in step s 103 _i(Yx), Δ P _iand Δ P (Mx) _i(Cx), so CPU 128 proceeds to step S105 and does not control image forming conditions.

In step S105, CPU 128 controls image processing system to form black tile images T (Kx) by use black image formation condition on intermediate transfer belt 51.

The black tile images T (Kx) that intermediate transfer belt 51 is formed is transferred to primary transfer nip portion according to intermediate transfer belt 51 again along the irradiation position rotating past toner height sensor unit 21 in arrow C direction.

Subsequently, toner image T (supx) (S106) of CPU 128 by using the yellow image formation condition be stored in ROM 130 or RAM 132 to form superposition.Here, have 15 to be superimposed on as the yellow tile images T (Yh) with the concentration scale of 127 of benchmark toner image, 31 ... with 255 concentration scale black tile images T (Kx) top on mode form the toner image T (supx) of superposition.That is, T (suph) is the toner image that benchmark toner image (having the yellow tile images of the concentration scale of 127) is transferred to be superimposed on the superposition on the top of the black tile images T (Kh) of the concentration scale with 127.

In step s 106, the toner image T (supx) being carried on the superposition on intermediate transfer belt 51 is sequentially transferred to the irradiation position of toner height sensor unit 21 along the rotation in arrow C direction according to intermediate transfer belt 51.

Subsequently, CPU 128 makes the light receiving position P (0) that toner height sensor unit 21 detects the light reflected from intermediate transfer belt 51 and light receiving position P (supx) (S107) of light that reflect from the toner image T (supx) of superposition.

In step s 107, similar with step S101, CPU 128 makes laser oscillator 701 measurement illumination be mapped on intermediate transfer belt 51 by convergent lens 702, and samples with the signal of predetermined cycle to the amount of the reflected light exported from line sensor 704.

Therefore, CPU 128 measures from the light intensity D (supx) of the light of each reflection the toner image T (supx) of superposition and two light intensity D (0) of light of reflecting from intermediate transfer belt 51 for the toner image of each superposition.Subsequently, the light receiving position P (supx) of CPU 128 by using above-mentioned method to detect the light receiving position P (0) of intermediate transfer belt 51 and the toner image T (supx) of superposition respectively from light intensity D (0) and D (supx).

In the present embodiment, similar with step S101, light receiving position P (0) is the upstream side in direction of toner image T (supx) of transmission one superposition and the mean value of the light receiving position of the reflected light from intermediate transfer belt 51 in downstream.

Subsequently, CPU 128 calculates light receiving position difference Δ P (supx) (S108) from the light receiving position P (0) measured in step s 107 and P (supx) by use formula 10.

Δ P (supx)=P (supx)-P (0) (x=a, b ..., p) ... (formula 10)

Subsequently, CPU 128 is from poor Δ P (supx) of the light receiving position of the toner image of superposition and the desired value Δ P be stored in ROM 130 _i(Yh) difference (formula 11) between calculates light receiving position difference Δ P (Kx) (S109) of black tile images.Here, due to have 127 concentration scale yellow tile images light receiving position difference Δ P (Yh) equal desired value Δ P by step S100 ~ S104 _i(Yh) desired value be stored in advance in ROM 130, therefore, is used.

Δ P (Kx)=Δ P (supx)-Δ P _i(Yh) (x=a, b ..., p) ... (formula 11)

Subsequently, CPU 128 determines whether light receiving position difference Δ P (Kx) of black tile images equals the desired value Δ P be stored in advance in ROM 130 _i(Kx) (S110).

Here, CPU 128 can be configured to by using the table of the corresponding relation between the amount of the toner representing light receiving position difference and adhesion to detect the amount Q (Kx) of the toner of the adhesion of black tile images from poor Δ P (Kx) of light receiving position.

Further, CPU 128 also can be configured to the concentration by using the table of the corresponding relation between the amount of the toner of representative adhesion and the concentration of black tile images T (Kx) to detect black tile images T (Kx).

If in step s 110, light receiving position difference Δ P (Kx) of black tile images equals desired value Δ P _i(Kx) concentration, so stopping being performed by toner height sensor unit 21 is controlled.

On the other hand, if light receiving position difference Δ P (Kx) is not equal to desired value Δ P in step s 110 _i(Kx), so CPU 128 controls black image formation condition (S111).Here, similar with step S104, control and the existing concentration of image forming conditions control similar, and, omit the description that it is detailed.

In step S111, CPU 128 stores the black image formation condition of change in RAM 132, and the concentration then stopping being performed by toner height sensor unit 21 controls.

Using the renewal by using Figure 13 to describe the look-up table as the image forming conditions control method performed in step S104 and S111.

Figure 13 (a) is representative for the formation of the printer unit output characteristics of the corresponding relation between the picture signal of the image of each single gray level grade be stored in ROM 130 and the concentration of image formed according to picture signal.

In Figure 13 (a), the printer unit output characteristics that curve X exhibits detects from arbitrary tile images, and straight line Z represents the desirable printer unit output characteristics detected from the tile images formed under suitable image forming conditions.Further, Figure 13 (b) is the look-up table (curve L) for the printer unit output characteristics (curve X) of the arbitrary tile images in Figure 13 (a) being converted to desirable printer unit output characteristics (straight line Z).

In the present embodiment, current printer unit output characteristics is created by using the image color determined from light receiving position difference Δ P (Yx), Δ P (Mx), Δ P (Cx) and Δ P (Kx), further, by using the known look-up table of method establishment for printer unit output characteristics being become desirable printer unit output characteristics.Owing to only detecting 16 image color data of the tile images with corresponding concentration scale for each color, therefore, current printer unit output characteristics is the curve of approximation from many data calculating accordingly.

Although describe the method for controlling image forming conditions by upgrading look-up table, the control of the image forming conditions in the present embodiment is not limited to above configuration.CPU 128 can be configured to after charging voltage and developing bias are changed the predetermined amount be stored in advance in ROM 130, upgrade look-up table as the control of the image forming conditions in the present embodiment.Or multiple look-up tables that CPU 128 can be configured to from being stored in advance ROM 130 select suitable look-up table.As an alternative, CPU 128 also can be configured to primary transfer voltage to change the predetermined amount be stored in advance in ROM 130.

(the second embodiment)

First embodiment of the present embodiment from above-mentioned on following point is different.Other key element in the present embodiment is identical with corresponding those in the first above-mentioned embodiment, and their description is omitted.

In a first embodiment, by using toner height sensor unit 21 (Fig. 1) measurement from the light intensity of the reflected light of the tile images on intermediate transfer belt 51.In contrast, in the present embodiment, by using toner height sensor unit 22 (Fig. 1), after being carried on the tile images on intermediate transfer belt 51 and being transferred on recording materials P, measure the light intensity of the reflected light from the tile images be transferred on recording materials P.

Toner height sensor unit 22 is arranged on and extends to the transmission path of recording materials P of fixing device 9 from secondary transfer nip, and measurement illumination is mapped to and is transferred to the recording materials P of fixing device 9 according to the rotation of conveyer belt 58 and is transferred to the toner image on recording materials P at secondary transfer nip place.

Here, when the toner image T (supx) being carried on the superposition on recording materials P is transferred to the irradiation position of toner height sensor unit 22, the surface of the toner image T (supx) of superposition needs to be yellow toner image T (Yh).

Therefore, when measurement illumination is mapped to the toner height sensor unit 22 of the toner image be transferred on recording materials P by use, before being transferred on recording materials P, be carried on the toner image T (supx) of the superposition on intermediate transfer belt 51 and different in the first embodiment.Specifically, the toner image T (supx) of superposition intermediate transfer belt 51 formed be as have the first color benchmark toner image yellow tile images T (Yh) top on superpose the toner image of the superposition of the black tile images T (Kx) as the toner image with the second color.

When the toner image T (supx) superposed is transferred on recording materials P, the toner image T (supx) being carried on the superposition on recording materials P is the toner image T (supx) of the superposition superposing yellow tile images T (Yh) on the top of black tile images T (Kx).

Figure 14 (a) and 14 (b) are the sectional views of the major part of the image processing system of the present embodiment.By the method by using these figure to describe the toner image for the formation of superposition.For ease of describing, the black tile images as the toner image with the second color represents by 720, and the yellow tile images as benchmark toner image represents by 710, and the toner image of superposition represents by 730.

The yellow tile images 710 formed on the photosensitive drum 1 by developing cell 4Y is transferred on intermediate transfer belt 51 at primary transfer nip portion place, is then transferred to secondary transfer nip according to intermediate transfer belt 51 along the rotation in arrow C direction.But, now, do not apply secondary transfer printing voltage to secondary transfer roller 57 and secondary transfer printing opposed roller 56, and, band clearer 55 with similar mode when forming full-color toner image away from intermediate transfer belt 51.Therefore, yellow tile images 710 is again transferred to primary transfer nip portion while maintenance toner height.

Subsequently, black tile images 720 is formed on the photosensitive drum 1 by developing cell 4K, to be carried on intermediate transfer belt 51 and in the yellow tile images 710 transmitted by intermediate transfer belt 51 to be superimposed on.

Subsequently, black tile images 720 is transferred to be superimposed on the top of yellow tile images 710 at primary transfer nip portion place, and therefore forms the toner image 730 (Figure 14 (a)) of superposition.The toner image 730 of superposition is transferred to secondary transfer nip according to intermediate transfer belt 51 along the rotation in arrow C direction.In this timing, to be transmitted by paper feed roller 71 and 72 in paper feed cassette 7 and the recording materials P being adjusted its position and transmit timing by alignment roller 73 is transferred to secondary transfer nip.

When the toner image 730 superposed and recording materials P enter secondary transfer nip, secondary transfer printing is applied to secondary transfer roller 57 and secondary transfer printing opposed roller 56, further, the toner image 730 of superposition is transferred to (Figure 14 (b)) on recording materials P.Recording materials P is transferred to the irradiation position of toner height sensor unit 22 with the toner image 730 being carried on the superposition on recording materials P according to the rotation of conveyer belt 58, further, by toner height sensor unit 22 measured light intensity D (0) and D (3).Then, recording materials P is transferred to fixing device 9 with the toner image 730 being carried on the superposition on recording materials P, and the toner image 730 of superposition is fixed on recording materials P.

Because the surface being transferred to the toner image 730 of the superposition of the irradiation position of toner height sensor unit 22 is Yellow toner (yellow tile images 710), therefore, the light receiving position P (3) of the light reflected from the toner image 730 of superposition can accurately be detected.

The toner height of toner image 730 of superposition equal the toner height of black tile images 720 and the toner height of yellow tile images 710 and.Namely, the light receiving position of the light that the light receiving position of the light reflected on the surface of toner image 730 of superposition reflects from yellow tile images 710 changes the light receiving position of the amount corresponding with the toner height of black tile images, measures poor Δ P (2) of light receiving position of black tile images 720.

Therefore, the light receiving position Δ P (3) of the light that can reflect according to the toner image 730 from superposition and the light receiving position Δ P (1) of light reflected from yellow tile images 710 calculates light receiving position difference Δ P (2) of black tile images by use formula 5.The light receiving position P (0) of the light receiving position P (1) detected according to the light intensity D (1) from the yellow tile images 710 be transferred to separately under single color state on recording materials P and recording materials P calculates light receiving position difference Δ P (1) of the light reflected from yellow tile images 710.

Light receiving position difference Δ P (2) based on the black tile images calculated by above mode controls black image formation condition in the mode similar with the first embodiment.

Here, image forming conditions is charging voltage, developing bias, look-up table, primary transfer voltage and secondary transfer printing voltage etc.Control and the existing concentration of image forming conditions control similar, and, omit their detailed description.

(the 3rd embodiment)

The basic configuration of the present embodiment is identical with the first embodiment.Therefore, the parts identical or substantially the same with the first embodiment are endowed identical Reference numeral, omit the description that it is detailed, and, the part as the feature of the present embodiment will be described.

In the first and second embodiment, the toner image by using the image processing system comprising the developing cell of a photosensitive drums and respective color to form superposition.In the present embodiment, comprise multiple photosensitive drums by using and form with the image processing system of the corresponding multiple developing cells of in photosensitive drums the toner image superposed respectively.

Figure 15 is the schematic sectional view of the printer unit 100B of the present embodiment.

The image processing system 100 of the present embodiment comprises image formation unit Sy, Sm, Sc and Sk that the image being used as the toner image forming respective color forms assembly.Here, Sy represents the image formation unit forming yellow toner image, Sm represents the image formation unit forming magenta toner image, and Sc represents the image formation unit forming cyan toner image, and Sk represents the image formation unit forming black toner image.

The printer unit 100B of the present embodiment is configured such that yellow, magenta, cyan and black toner image by using image formation unit Sy, Sm, Sc and Sk to be formed are transferred on the intermediate transfer belt 51 as image bearing member, forms full-color toner image mutually to superpose successively.When being carried on the full-color toner image on intermediate transfer belt 51 and being transferred to secondary transfer nip, full-color toner image is transferred in this timing from the recording materials P that paper feed cassette 7 is transmitted, further, by using fixing device 9 to be fixed as full-colour image.

More specifically, when performing image forming operation, be driven to rotate with predetermined speed photosensitive drums 1y, 1m, 1c and 1k by corona charging device 2y, 2m, 2c and 2k by uniform charging.Subsequently, when photosensitive drums 1y, 1m, 1c and 1k expose based on the laser output signal standing color separated according to original copy by exposure device 3y, 3m, 3c and 3k, photosensitive drums 1y, 1m, 1c and 1k form the electrostatic latent image corresponding with the image of respective color in the above.

Subsequently, the electrostatic latent image corresponding with yellow image photosensitive drums 1y formed is developed as yellow toner image by the developing cell 4y being applied in developing bias.By applying primary transfer voltage at primary transfer nip portion place to primary transfer roller 53y, yellow toner image is transferred on intermediate transfer belt 51, at primary transfer nip portion place, primary transfer roller 53y is pressed against photosensitive drums 1y by the intermediate transfer belt 51 between primary transfer roller 53y and photosensitive drums 1y.Intermediate transfer belt 51 by driven roller 50, secondary transfer printing opposed roller 56 and jockey pulley 52 tensioning, and is driven to by the rotary actuation of driven roller 50 and rotates along arrow C direction.

Be carried on yellow toner image on intermediate transfer belt 51 and be transferred to primary transfer nip portion according to intermediate transfer belt 51 along the rotation in arrow C direction, at primary transfer nip portion place, primary transfer roller 53m is pressed against photosensitive drums 1m by the intermediate transfer belt 51 between primary transfer roller 53m and photosensitive drums 1m.Then, equally in image formation unit Sm, by applying primary transfer voltage, the magenta toner image that photosensitive drums 1m is formed is transferred on the top of the yellow toner image be superimposed on intermediate transfer belt 51.

Subsequently, similarly, time on the toner image of the superposition of the yellow that cyan and black toner image are transferred and are superimposed on successively on intermediate transfer belt 51 and magenta toner image, intermediate transfer belt 51 forms full-color toner image.At secondary transfer nip place, described full-color toner image is transferred in the synchronous time from the recording materials P that paper feed cassette 7 is transmitted, at secondary transfer nip place, secondary transfer printing opposed roller 56m is pressed against secondary transfer roller 57 by the intermediate transfer belt 51 between secondary transfer printing opposed roller 56m and secondary transfer roller 57.

Not to be transferred on intermediate transfer belt 51 and the remaining toner still residued on photosensitive drums 1y, 1m, 1c and 1k is removed according to be rotated through bulging clearer 6y, 6m, 6c and 6k of photosensitive drums 1y, 1m, 1c and 1k.Further, not to be transferred on recording materials P and still to residue in the remaining toner on intermediate transfer belt 51 and be removed according to the band clearer 55 that is rotated through of intermediate transfer belt 51.

The full-color toner image be transferred on recording materials P is transferred to fixing device 9 by delivery roll (not shown).In fixing device 9, to be held between fixing roller 91 and 92 and the full-color toner image transmitted by fixing roller 91 and 92 and recording materials P are heated by the well heater (not shown) be arranged in fixing roller 91, to allow fixing for full-color toner image thus on recording materials P.

Below, the operation using tile images to perform the image processing system 100 of the present embodiment that concentration controls will be described through.The toner image with the first color in the present embodiment is the yellow tile images T (ref) by being used as the image formation unit Sy of the first image formation unit to be formed under predetermined image forming conditions, further, photosensitive drums 1y is the first photosensitive-member.Further, the toner image with the second color in the present embodiment is the black tile images T (Kx) by being used as the image formation unit Sk of the second image formation unit to be formed, and photosensitive drums 1k is the second photosensitive-member.

When starting concentration and controlling, the printer unit 100B of the present embodiment forms tile images T (Yx), T (Mx), T (Cx) and T (Kx) respectively based on the image forming conditions be stored in ROM 130 or RAM 132 on photosensitive drums 1y, 1m, 1c and 1k.Subsequently, be carried on the tile images T (Yx) on photosensitive drums 1y, 1m, 1c and 1k, T (Mx), T (Cx) and T (Kx) to be transferred on intermediate transfer belt 51 at corresponding primary transfer nip portion place.In this case, black, cyan, magenta and yellow tile images is carried at intermediate transfer belt 51 successively from the irradiation position of toner height sensor unit 21 to the upstream of the sense of rotation of intermediate transfer belt 51.

Be carried on the tile images T (Yx) on intermediate transfer belt 51, T (Mx), T (Cx) and T (Kx) are sequentially transferred to toner height sensor unit 21 along the rotation in arrow C direction irradiation position according to intermediate transfer belt 51.Toner height sensor unit 21 by measure illumination be mapped to be transferred to irradiation position yellow, magenta and cyan tile images T (Yx), T (Mx) and T (Cx), and detection light receiving position P (Yx), the P (Mx) of light that reflect from corresponding tile images and P (C).In this case, not detected from the light receiving position P (Kx) of the light of black tile images reflection.

The printer unit 100B of the present embodiment is configured such that the upstream of the sense of rotation (arrow C direction) from intermediate transfer belt 51 sets gradually yellow image forming unit Sy, black image forming unit Sk and toner height sensor unit 21.Therefore, in order to form the toner image T (supx) of superposition, black tile images T (Kx) must be transferred to the primary transfer nip portion of yellow image forming unit Sy, at the primary transfer nip portion place of yellow image forming unit Sy, primary transfer roller 53y is pressed against photosensitive drums 1y by the intermediate transfer belt 51 between primary transfer roller 53y and photosensitive drums 1y.

Therefore, the present embodiment has band clearer 55 can not remove black tile images T (Kx) configuration close to or away from intermediate transfer belt 51.

When yellow, magenta, cyan and black tile images T (Yx), T (Mx), T (Cx) and T (Kx) are transferred to secondary transfer nip, do not apply secondary transfer printing voltage to the secondary transfer roller 57 of the present embodiment and secondary transfer printing opposed roller 56.Further, become the toner image T (supx) of superposition in yellow image forming unit Sy at black tile images T (Kx) before, band clearer 55 is away from intermediate transfer belt 51.

Therefore, while maintenance toner height, black tile images T (Kx) is transferred to the primary transfer nip portion of yellow image forming unit Sy.

Be carried on the mode that the black tile images T (Kx) on intermediate transfer belt 51 is superimposed on black tile images T (Kx) at the primary transfer nip portion place of yellow image forming unit Sy with the yellow tile images T (ref) formed under predetermined image forming conditions to be transferred, further, the toner image T (supx) of superposition is produced.The toner image T (supx) being carried on the superposition on intermediate transfer belt 51 is transferred to the irradiation position of toner height sensor unit 21 according to intermediate transfer belt 51 again along the rotation in arrow C direction, further, by using toner height sensor unit 21 to detect light receiving position P (supx).

Similar with the first embodiment, toner height sensor unit 21 also detects the light receiving position P (0) of the light reflected from intermediate transfer belt 51 when detecting the light receiving position of the light reflecting from tile images T (Yx), T (Mx) and T (Cx) and reflect from the toner image T (supx) of superposition.

Subsequently, by using above-mentioned method to calculate corresponding light receiving position difference Δ P (Yx), Δ P (Mx), Δ P (Cx) and Δ P (Kx) from the light receiving position P (0) detected by toner height sensor unit 21, P (Yx), P (Mx), P (Cx) and P (supx).Similar with the first embodiment, poor Δ P (Yx) of the light receiving position based on yellow, magenta and cyan tile images, Δ P (Mx) and Δ P (Cx) control yellow, magenta and cyan image formation condition.

And, according to the difference between light receiving position difference Δ P (supx) of the toner image of superposition and light receiving position difference Δ P (ref) of the yellow tile images that formed under predetermined image forming conditions, calculate poor Δ P (Kx) of light receiving position of black tile images.Here, light receiving position difference Δ P (ref) of the yellow tile images formed under predetermined image forming conditions can be detected according to the light receiving position P (ref) of the light from the yellow tile images reflection of measuring individually under a single state.

Here, image forming conditions is charging voltage, developing bias, look-up table and primary transfer voltage etc.Control and the existing concentration of image forming conditions control similar, and, omit the description that it is detailed.

Further, the amount that the image processing system 100 of the present embodiment can be configured to light receiving position difference Δ P (Yx) according to yellow, magenta and cyan tile images, poor Δ P (Kx) of light receiving position of Δ P (Mx) and Δ P (Cx) and black tile images detects the toner of the adhesion of respective color.By this configuration, by the amount using light receiving position difference Δ P (Yx) of table from the tile images of respective color of the corresponding relation between the amount of the toner of above-mentioned representative light receiving position difference and adhesion, Δ P (Mx), Δ P (Cx) and Δ P (Kx) to detect the toner of the adhesion of respective color.Another that the table of the corresponding relation between the amount of toner by using representative to adhere to and concentration also can be used to detect the concentration of the tile images of respective color from the amount of the toner of the adhesion of the tile images of respective color configures.

(the 4th embodiment)

Three embodiment of the present embodiment from above-mentioned on following point is different.Other key element in the present embodiment is identical with corresponding those in the 3rd above-mentioned embodiment, and their description is omitted.

In the image processing system of the 3rd embodiment, need from when black tile images is transferred to intermediate transfer belt 51 to when the light receiving position of toner image superposed is detected, intermediate transfer belt 51 being revolved the circle that to turn around or more.But, in the image processing system of the present embodiment, can intermediate transfer belt 51 is revolved turn around before detect the light receiving position of the toner image of superposition.

Figure 16 is the schematic sectional view of the printer unit 100B of the present embodiment.

The upstream of the sense of rotation (arrow C direction) that the printer unit 100B in the image processing system 100 of the present embodiment is configured such that from intermediate transfer belt 51 sets gradually black image forming unit Sk, yellow image forming unit Sy and toner height sensor unit 21.

Below, the operation using tile images to perform the image processing system 100 of the present embodiment that concentration controls will be described through.In the present embodiment, the benchmark toner image with the first color is the yellow tile images formed under predetermined image forming conditions, and the toner image with the second color is black tile images.

When starting concentration and controlling, in the printer unit 100B of the present embodiment, intermediate transfer belt 51 carries formed based on the image forming conditions that is stored in ROM 130 or RAM 132 tile images T (Kx), T (Yx), T (Mx) and T (Cx).In this case, cyan, magenta, yellow and black tile images is carried at intermediate transfer belt 51 successively from the irradiation position of toner height sensor unit 21 to the upstream of the sense of rotation of intermediate transfer belt 51.

Be carried on black tile images T (Kx) on intermediate transfer belt 51 according to intermediate transfer belt 51 along arrow C direction be rotated in the irradiation position being transferred to toner height sensor unit 21 before be transferred to the primary transfer nip portion of yellow image forming unit Sy.In this case, yellow image forming unit Sy is to be carried on the yellow tile images formed under the upper mode superposing yellow tile images of the black tile images T (Kx) on intermediate transfer belt 51 is formed in predetermined image forming conditions on photosensitive drums 1y.Subsequently, the yellow tile images T (ref) that yellow image forming unit Sy is formed under being transferred in predetermined image forming conditions is superimposed on black tile images T (Kx) to make it, and forms the toner image T (supx) of superposition.

Subsequently, the toner image T (supx) of the superposition on intermediate transfer belt 51 and yellow, magenta and cyan tile images T (Yx), T (Mx) and T (Cx) are transferred to toner height sensor unit 21 along the rotation in arrow C direction irradiation position according to intermediate transfer belt 51 is carried on.

Measurement illumination is mapped to the tile images T (Yx), T (Mx), T (Cx) and the T (supx) that are transferred to irradiation position successively and the intermediate transfer belt 51 carrying above image by toner height sensor unit 21.Therefore, from light receiving position P (Yx), the P (Mx) of the light of yellow, magenta and the reflection of cyan tile images and P (Cx), detected from the light receiving position P (supx) of the light of the toner image reflection of superposition and the light receiving position P (0) of light that reflects from intermediate transfer belt 51.

The image processing system 100 of the present embodiment calculates corresponding light receiving position difference Δ P (Yx), Δ P (Mx), Δ P (Cx) and Δ P (Kx) according to the light receiving position P (Yx) detected by toner height sensor unit 21, P (Mx), P (Cx), P (supx) and P (0) by using above-mentioned method.Similar with the first embodiment, poor Δ P (Yx) of the light receiving position based on yellow, magenta and cyan tile images, Δ P (Mx) and Δ P (Cx) control yellow, magenta and cyan image formation condition.

And, according to the difference between light receiving position difference Δ P (supx) of the light of the toner image reflection from superposition and light receiving position difference Δ P (ref) of the yellow tile images that formed under predetermined image forming conditions, calculate poor Δ P (Kx) of light receiving position of black tile images.Here, according to the light receiving position of the light reflected from yellow tile images T (ref) measured individually under a single state, light receiving position difference Δ P (ref) of the yellow tile images formed under predetermined image forming conditions can be calculated.

Here, image forming conditions is charging voltage, developing bias, look-up table and primary transfer voltage etc.Control and the existing concentration of image forming conditions control similar, and, omit the description that it is detailed.

Further, the image processing system 100 of the present embodiment can be configured to the amount detecting the toner of the adhesion of respective color from poor Δ P (Kx) of light receiving position of light receiving position difference Δ P (Yx) of yellow, magenta and cyan tile images, Δ P (Mx) and Δ P (Cx) and black tile images.By this configuration, by the amount using light receiving position difference Δ P (Yx) of table according to respective color component of the corresponding relation between the amount of the toner of above-mentioned representative light receiving position difference and adhesion, Δ P (Mx), Δ P (Cx) and Δ P (Kx) to detect the toner of the adhesion of the tile images of respective color.Another that the table of the corresponding relation between the amount of toner by using representative to adhere to and concentration also can be used to detect the concentration of the tile images of respective color from the amount of the toner of the adhesion of the tile images of respective color configures.

According to the present embodiment, black tile images according to intermediate transfer belt 51 along arrow C direction rotate past the irradiation position of toner height sensor unit 21 time, black tile images be carried on intermediate transfer belt 51 as superposition toner image.That is, the black tile images in a single state is not transferred to along the rotation in arrow C direction the position that the toner residued on intermediate transfer belt 51 removed by band clearer 55 according to intermediate transfer belt 51.Therefore, different from the 3rd embodiment, band clearer 55 does not need to be configured to close to or away from intermediate transfer belt 51, therefore, compared with the image processing system of the 3rd embodiment, detection can be made shorter for the stop time required for light receiving position.

Further, in the first to the four embodiment, by as have the second color toner image black tile images on superpose yellow tile images as the benchmark toner image with the first color, form the toner image of superposition.But the benchmark toner image with the first color is not limited to above configuration with the combination of the toner image with the second color.In the present embodiment, the measurement light irradiated from laser oscillator 701 has the wavelength of 780 [nm].If the wavelength measuring light is 680 [nm], so the reflectivity (Fig. 6 (c)) of cyan is about 10 [%] and reduces from the light quantity of the light of cyan tile images reflection.Therefore, can use and form the toner image of superposition by superposing magenta tile images in cyan tile images and indirectly detect the configuration of the light receiving position difference of cyan tile images.That is, if the toner image with the first color is made up of the toner of the color with the reflectivity higher than the toner image with the second color, so any configuration can be used.

Further, although first toner image that will be superimposed on the toner image of the second color is benchmark toner image T (ref) in the first to the four embodiment, the toner image of the first color is not limited to this configuration.More preferably, the toner image of the first color can have the concentration scale of the stacked underclad portion for covering such as intermediate transfer belt 51 or recording materials P equably of corresponding toner.By this configuration, the toner image T (supx) that the toner image of the second color superposes the superposition of the toner image of the first color has the surface covered by the toner of the first color.Therefore, the measurement light irradiated from laser oscillator 701 is reflected from the surface of the toner image T (supx) of the superposition covered by the toner of the first color, thus causes the accurate detection of the light receiving position P (supx) of the toner image T (supx) of the increase of the amount of the reflected light received by line sensor 704 and superposition.

Further, the first to the four embodiment has according to the light receiving position poor configuration that control image forming conditions of the difference between light receiving position difference and desired value based on the tile images of respective color.But, the control of image forming conditions is not limited to above configuration, further, the amount of the toner of the adhesion that the table based on the corresponding relation between the representative light receiving position difference be stored in advance by use in ROM 130 and the amount of the toner adhered to can be used to change controls the configuration of image forming conditions from the light receiving position difference of the tile images of respective color.As an alternative, the configuration controlling image forming conditions based on the concentration by using the table of the corresponding relation between the amount of the toner of the adhesion of the representative respective color component be stored in advance in ROM 130 and concentration to change from the amount of the toner of the adhesion of the tile images of respective color can also be used.

And, in the first to the four embodiment, in order to form the toner image T (supx) of superposition, the toner image being superimposed on the first color on the toner image of the second color is benchmark toner image T (ref), further, corresponding with the toner height of the toner image of the first color light receiving position difference is controlled as and equals desired value.That is, with the identical image forming conditions of benchmark toner image under form the first toner image, make the light receiving position of the first toner image difference can equal the light receiving position difference (desired value) of benchmark toner image.But the image forming conditions of the toner image of the first color is not limited to above configuration.The toner image of the first color can be configured to be formed under image forming conditions that is identical with those image forming conditions allowing to obtain in the scope of the height identical with benchmark toner image T (ref) or that be equal to.

Further, the toner image of the first color be superimposed on the toner image of the second color in order to the toner image T (supx) forming superposition is not limited to be controlled as the formation of the image forming conditions of the toner image of the first color the configuration making the light receiving position difference corresponding with the toner height of the toner image of the first color can equal desired value.

When using above configuration, following configuration can be used: the multiple toner images forming multiple first color, further, regulation has the toner image of the first color of the light receiving position difference closest to desired value in the light receiving position difference corresponding with the toner height of the toner image of the first color.Subsequently, the toner image of the first color formed under the image forming conditions closest to the light receiving position difference of desired value is being provided to be superimposed on the toner image of the second color, and, form the toner image T (supx) of superposition.

And, in the first to the four embodiment, the benchmark toner image T (ref) be carried on intermediate transfer belt 51 or on recording materials P is the toner image that will be superimposed on the first color on the toner image of the second color when forming toner image T (supx) of superposition.But, other configuration any can be used.Following configuration can be used: detect the light receiving position corresponding with the toner height of benchmark toner image T (ref) by toner height sensor unit 21 poor, and, the corresponding relation between specified image formation condition and toner height.Subsequently, when forming toner image T (supx) of superposition, the toner image of the first color is formed under allowing toner height to be the image forming conditions of N times of the toner height of benchmark toner image T (ref), and is superimposed on the toner image of the second color.Term N can be doubly twice, three times, 1/3rd times or 1/4th times.Further, the toner image by forming the first color under allowing light receiving position difference instead of toner height to be N image forming conditions doubly can also be used and the toner image superposing the first color on the toner image of the second color forms the configuration of the toner image T (supx) of superposition.

In the first to the four embodiment, difference between the light receiving position difference and the light receiving position difference of the toner image T (supx) superposed of benchmark toner image T (ref), detects the light receiving position corresponding with the toner height of the toner image of the second color.Here, the light receiving position difference of term benchmark toner image T (ref) is the difference between the light receiving position from the reflected light of benchmark toner image T (ref) and the light receiving position from the reflected light of intermediate transfer belt 51.Further, the light receiving position difference of the toner image T (supx) of term superposition is the difference between the light receiving position from the reflected light of the toner image T (supx) superposed and the light receiving position from the reflected light of intermediate transfer belt 51.But, if specified in advance from the light receiving position of the light of intermediate transfer belt 51 reflection, the configuration detecting the light receiving position corresponding with the toner height of the toner image of the second color from the difference between the light receiving position and the light receiving position of the toner image T (supx) of superposition of benchmark toner image T (ref) so can be used.

Reference numerals list

T (ref) benchmark toner image (there is the yellow tile images T (Yh) of the concentration scale of 127)

T (Kx) black tile images

The toner image that T (supx) superposes

51 intermediate transfer belts

701 laser oscillators

704 line sensors

128 CPU

Claims (9)

1. an image processing system, comprising:

First image forms assembly, forms the first toner image for the toner being different from the color of black by use;

Second image forms assembly, for forming the second toner image by the toner of use black;

Image bearing member, described first toner image and described second toner image are transferred to described image bearing member;

Controller, described controller is configured to control first image and forms assembly to form benchmark toner image on described image bearing member, and control the first image to form assembly and the second image and form assembly to form the toner image of superposition on described image bearing member, the toner image of wherein said superposition comprises and forms by the first image the first tile images that assembly formed and form by the second image the second tile images that assembly formed, wherein said first tile images is superimposed upon in described second tile images, the toner height of wherein said first tile images is determined in advance,

Illumination module, described illumination module is for light shining the toner image of described benchmark toner image and described superposition;

Light-receiving module, described light-receiving module for receive when described illumination module use up irradiate described benchmark toner image time from described benchmark toner image reflected light and receive when described illumination module uses up the toner image irradiating described superposition from the reflected light of the toner image of described superposition; With

Toner concentration detection components, described toner concentration detection components is used for the concentration detecting the second tile images comprised in the toner image of described superposition based on the light receiving position of the reflected light from benchmark toner image in described light-receiving module and the light receiving position of the reflected light from the described toner image superposed in described light-receiving module.

2. an image processing system, comprising:

First image forms assembly, forms the first toner image for the toner being different from the color of black by use;

Second image forms assembly, for forming the second toner image by the toner of use black;

Image bearing member, described first toner image and described second toner image are transferred to described image bearing member;

Controller, described controller is configured to control first image and forms assembly to form benchmark toner image on described image bearing member, and control the first image to form assembly and the second image and form assembly to form the toner image of superposition on described image bearing member, the toner image of wherein said superposition comprises and forms by the first image the first tile images that assembly formed and form by the second image the second tile images that assembly formed, wherein said first tile images is superimposed upon in described second tile images, the toner height of wherein said first tile images is determined in advance,

Illumination module, described illumination module is for light shining the toner image of described benchmark toner image and described superposition;

Light-receiving module, described light-receiving module for receive when described illumination module use up irradiate described benchmark toner image time from described benchmark toner image reflected light and receive when described illumination module uses up the toner image irradiating described superposition from the reflected light of the toner image of described superposition; With

Control Component, described Control Component is for controlling the image forming conditions for the formation of the second toner image based on the light receiving position of the reflected light from benchmark toner image in described light-receiving module and the light receiving position of the reflected light from the toner image superposed in described light-receiving module.

3. an image processing system, comprising:

First image forms assembly, forms the first toner image for the toner being different from the color of black by use;

Second image forms assembly, for forming the second toner image by the toner of use black;

Image bearing member, described first toner image and described second toner image are transferred to described image bearing member;

Controller, described controller is configured to control first image and forms assembly to form benchmark toner image on described image bearing member, and control the first image to form assembly and the second image and form assembly to form the toner image of superposition on described image bearing member, the toner image of wherein said superposition comprises and forms by the first image the first tile images that assembly formed and form by the second image the second tile images that assembly formed, wherein said first tile images is superimposed upon in described second tile images, the toner height of wherein said first tile images is determined in advance,

Illumination module, described illumination module is for light shining the toner image of described benchmark toner image and described superposition;

Light-receiving module, described light-receiving module for receive when described illumination module use up irradiate described benchmark toner image time from described benchmark toner image reflected light and receive when described illumination module uses up the toner image irradiating described superposition from the reflected light of the toner image of described superposition; With

Toner height detection assembly, described toner height detection assembly is used for the toner height detecting the second tile images comprised in the toner image of described superposition based on the light receiving position of the reflected light from benchmark toner image in described light-receiving module and the light receiving position of the reflected light from the toner image superposed in described light-receiving module.

4. according to the image processing system of any one in claims 1 to 3, wherein, described controller controls described first image and forms assembly based on predetermined image forming conditions formation benchmark toner image, and

Described controller controls described first image formation assembly and forms the first tile images based on predetermined image forming conditions.

5. according to the image processing system of any one in claims 1 to 3, wherein, described light-receiving module comprises multiple photo detector, described multiple photo detector arranges along from the first light receiving position to the direction of the second light receiving position, wherein, described first light receiving position is the light receiving position of the reflected light from benchmark toner image in described light-receiving module, and described second light receiving position is the light receiving position of the reflected light of the toner image from described superposition in described light-receiving module.

6. according to the image processing system of any one in claims 1 to 3,

Wherein, the first image formation unit is positioned at the downstream of the second image formation unit in the transmission direction of described image bearing member.

7. image processing system according to claim 1, wherein, described toner concentration detection components detects the concentration of the second tile images comprised in the toner image of described superposition based on the difference between the light receiving position of the reflected light from described benchmark toner image in described light-receiving module and the light receiving position of the reflected light from the described toner image superposed in described light-receiving module.

8. image processing system according to claim 2, wherein, described Control Component is based on the poor image forming conditions controlled for the formation of the second toner image between the light receiving position of the reflected light from benchmark toner image in described light-receiving module and the light receiving position of the reflected light from the toner image superposed in described light-receiving module.

9. image processing system according to claim 3, wherein, described toner height detection assembly detects the toner height of the second tile images comprised in the toner image of described superposition based on the difference between the light receiving position of the reflected light from benchmark toner image in described light-receiving module and the light receiving position of the reflected light from the toner image superposed in described light-receiving module.